Name: On Youth, Old Age, Life and Death, and Respiration
Author: Aristotle

Ross (OCT, 1955) · Ross (1908)

Ross (1908)

Chapter 1 (467b10–468a12)

467b

10 Περὶ δὲ νεότητος καὶ γήρως καὶ περὶ ζωῆς καὶ θανάτου

λεκτέον νῦν· ἅμα δὲ καὶ περὶ ἀναπνοῆς ἀναγκαῖον ἴσως τὰς

αἰτίας εἰπεῖν· ἐνίοις γὰρ τῶν ζῴων διὰ τοῦτο συμβαίνει τὸ

ζῆν καὶ τὸ μὴ ζῆν. ἐπεὶ δὲ περὶ ψυχῆς ἐν ἑτέροις διώρισται,

καὶ δῆλον ὅτι οὐχ οἷόν τ' εἶναι σῶμα τὴν οὐσίαν αὐτῆς, ἀλλ'

15 ὅμως ὅτι γ' ἔν τινι τοῦ σώματος ὑπάρχει μορίῳ φανερόν,

καὶ ἐν τούτῳ τινὶ τῶν ἐχόντων δύναμιν ἐν τοῖς μορίοις, τὰ

μὲν οὖν ἄλλα τῆς ψυχῆς ἢ μόρια ἢ δυνάμεις, ὁποτέρως

ποτὲ δεῖ καλεῖν, ἀφείσθω τὰ νῦν· ὅσα δὲ ζῷα λέγεται

καὶ ζῆν, ἐν μὲν τοῖς ἀμφοτέρων τούτων τετυχηκόσι (λέγω

20 δ' ἀμφοτέρων τοῦ τε ζῷον εἶναι καὶ τοῦ ζῆν) ἀνάγκη ταὐτὸν

εἶναι καὶ ἓν μόριον καθ' ὅ τε ζῇ καὶ καθ' ὃ προςαγορεύομεν

αὐτὸ ζῷον· τὸ μὲν γὰρ ζῷον ᾗ ζῷον ἀδύνατον μὴ

ζῆν· ᾗ δὲ ζῇ, ταύτῃ ζῷον ὑπάρχειν οὐκ ἀναγκαῖον· τὰ γὰρ

φυτὰ ζῇ μέν, οὐκ ἔχει δ' αἴσθησιν, τῷ δ' αἰσθάνεσθαι τὸ

25 ζῷον πρὸς τὸ μὴ ζῷον διορίζομεν. ἀριθμῷ μὲν οὖν ἀναγκαῖον

ἓν εἶναι καὶ τὸ αὐτὸ τοῦτο τὸ μόριον, τῷ δ' εἶναι

πλείω καὶ ἕτερα· οὐ γὰρ ταὐτὸ τὸ ζῴῳ εἶναι καὶ τὸ ζῆν.

ἐπεὶ οὖν τῶν ἰδίων αἰσθητηρίων ἕν τι κοινόν ἐστιν αἰσθητήριον,

εἰς ὃ τὰς κατ' ἐνέργειαν αἰσθήσεις ἀναγκαῖον ἀπαντᾶν, τοῦτο

30 δ' ἂν εἴη μέσον τοῦ πρόσθεν καλουμένου καὶ ὄπισθεν (ἔμπροσθεν

μὲν γὰρ λέγεται ἐφ' ὅ ἐστιν ἡμῖν ἡ αἴσθησις, ὄπισθεν

δὲ τὸ ἀντικείμενον), ἔτι δὲ διῃρημένου τοῦ σώματος τῶν

ζώντων πάντων τῷ τ' ἄνω καὶ κάτω (πάντα γὰρ ἔχει τὸ

ἄνω καὶ τὸ κάτω, ὥστε καὶ τὰ φυτά), δῆλον ὅτι τὴν θρεπτικὴν

10We must now treat of youth and old age and life and death. We must probably also at the same time state the causes of respiration as well, since in some cases living and the reverse depend on this.
We have elsewhere given a precise account of the soul, and while it is clear that its essential reality cannot be corporeal, 15yet manifestly it must exist in some bodily part which must be one of those possessing control over the members. Let us for the present set aside the other divisions or faculties of the soul (whichever of the two be the correct name). But as to being what is called an animal and a living thing, we find that in all beings endowed with both characteristics (viz. 20being an animal and being alive) there must be a single identical part in virtue of which they live and are called animals; for an animal qua animal cannot avoid being alive. But a thing need not, though alive, be animal, for plants live without having sensation, 25and it is by sensation that we distinguish animal from what is not animal.
This organ, then, must be numerically one and the same and yet possess multiple and disparate aspects, for being animal and living are not identical. Since then the organs of special sensation have one common organ in which the senses when functioning must meet, 30and this must be situated midway between what is called before and behind (we call 'before' the direction from which sensation comes, 'behind' the opposite), further, since in all living things the body is divided into upper and lower (they all have upper and lower parts, so that this is true of plants as well), clearly the nutritive principle must be situated midway between these regions.

468a

1 ἀρχὴν ἔχοι ἂν ἐν μέσῳ τούτων· καθ' ὃ μὲν γὰρ εἰςέρχεται

μόριον ἡ τροφή, ἄνω καλοῦμεν, πρὸς αὐτὸ βλέποντες

ἀλλ' οὐ πρὸς τὸ περιέχον ὅλον, κάτω δὲ καθ' ὃ τὸ

περίττωμα ἀφίησι τὸ πρῶτον. ἔχει δ' ἐναντίως τοῖς φυτοῖς

5 τοῦτο καὶ τοῖς ζῴοις· τῷ μὲν γὰρ ἀνθρώπῳ διὰ τὴν ὀρθότητα

μάλιστα ὑπάρχει τοῦτο τῶν ζῴων, τὸ ἔχειν τὸ ἄνω

μόριον πρὸς τὸ τοῦ παντὸς ἄνω, τοῖς δ' ἄλλοις μεταξύ· τοῖς

δὲ φυτοῖς ἀκινήτοις οὖσι καὶ λαμβάνουσιν ἐκ τῆς γῆς τὴν

τροφὴν ἀναγκαῖον ἀεὶ κάτω τοῦτ' ἔχειν τὸ μόριον. ἀνάλογον

10 γάρ εἰσιν αἱ ῥίζαι τοῖς φυτοῖς καὶ τὸ καλούμενον στόμα τοῖς

ζῴοις, δι' οὗ τὴν τροφὴν τὰ μὲν ἐκ τῆς γῆς λαμβάνει, τὰ

δὲ δι' αὑτῶν.

1That part where food enters we call upper, considering it by itself and not relatively to the surrounding universe, while downward is that part by which the primary excrement is discharged.
5Plants are the reverse of animals in this respect. To man in particular among the animals, on account of his erect stature, belongs the characteristic of having his upper parts pointing upwards in the sense in which that applies to the universe, while in the others these are in an intermediate position.
But in plants, owing to their being stationary and drawing their sustenance from the ground, the upper part must always be down; 10for there is a correspondence between the roots in a plant and what is called the mouth in animals, by means of which they take in their food, whether the source of supply be the earth or each other's bodies.

Chapter 2 (468a13–468b15)

Τριῶν δὲ μερῶν ὄντων εἰς ἃ διαιρεῖται πάντα τὰ τέλεια

τῶν ζῴων, ἑνὸς μὲν ᾗ δέχεται τὴν τροφήν, ἑνὸς δ' ᾗ

15 τὸ περίττωμα προΐεται, τρίτου δὲ τοῦ μέσου τούτων, τοῦτο ἐν

μὲν τοῖς μεγίστοις τῶν ζῴων καλεῖται στῆθος, ἐν δὲ τοῖς ἄλλοις

τὸ ἀνάλογον, διήρθρωται δὲ μᾶλλον ἑτέροις ἑτέρων.

ὅσα δ' αὐτῶν ἐστι πορευτικά, πρόσκειται καὶ μόρια τὰ πρὸς

ταύτην τὴν ὑπηρεσίαν, οἷς τὸ πᾶν οἴσουσι κύτος, σκέλη τε

20 καὶ πόδες καὶ τὰ τούτοις ἔχοντα τὴν αὐτὴν δύναμιν. ἀλλ'

ἥ γε τῆς θρεπτικῆς ἀρχὴ ψυχῆς ἐν τῷ μέσῳ τῶν τριῶν

μορίων καὶ κατὰ τὴν αἴσθησιν οὖσα φαίνεται καὶ κατὰ τὸν

λόγον· πολλὰ γὰρ τῶν ζῴων ἀφαιρουμένου ἑκατέρου τῶν μορίων,

τῆς τε καλουμένης κεφαλῆς καὶ τοῦ δεκτικοῦ τῆς τροφῆς,

25 ζῇ μεθ' οὗπερ ἂν ᾖ τὸ μέσον. δῆλον δ' ἐπὶ τῶν ἐντόμων,

οἷον σφηκῶν τε καὶ μελιττῶν, τοῦτο συμβαῖνον· καὶ

τῶν μὴ ἐντόμων δὲ πολλὰ διαιρούμενα δύναται ζῆν διὰ τὸ

θρεπτικόν. τὸ δὲ τοιοῦτον μόριον ἐνεργείᾳ μὲν ἔχει ἕν, δυνάμει

δὲ πλείω· τὸν αὐτὸν γὰρ συνέστηκε τοῖς φυτοῖς τρόπον·

30 καὶ γὰρ τὰ φυτὰ διαιρούμενα ζῇ χωρίς, καὶ γίνεται πολλὰ

ἀπὸ μιᾶς ἀρχῆς δένδρα. δι' ἓν δ' αἰτίαν τὰ μὲν οὐ δύναται

διαιρούμενα ζῆν, τὰ δ' ἀποφυτεύεται τῶν φυτῶν, ἕτερος

13All perfectly formed animals are to be divided into three parts, one that by which food is taken in, one that by which excrement is discharged, 15and the third the region intermediate between them. In the largest animals this latter is called the chest and in the others something corresponding; in some also it is more distinctly marked off than in others. All those also that are capable of progression have additional members subservient to this purpose, by means of which they bear the whole trunk, 20to wit legs and feet and whatever parts are possessed of the same powers. Now it is evident both by observation and by inference that the source of the nutritive soul is in the midst of the three parts. For many animals, when either part-the head or the receptacle of the food-is cut off, retain life in that member to which the middle remains attached. 25This can be seen to occur in many insects, e.g. wasps and bees, and many animals also besides insects can, though divided, continue to live by means of the part connected with nutrition.
While this member is indeed in actuality single, yet potentially it is multiple, for these animals have a constitution similar to that of Plants; 30plants when cut into sections continue to live, and a number of trees can be derived from one single source. A separate account will be given of the reason why some plants cannot live when divided, while others can be propagated by the taking of slips.

468b

1 ἔσται λόγος. ἀλλ' ὁμοίως ἔχει κατά γε τοῦτο τά τε φυτὰ

καὶ τὸ τῶν ἐντόμων γένος. ἀνάγκη δὲ καὶ τὴν θρεπτικὴν

ψυχὴν ἐνεργείᾳ μὲν ἐν τοῖς ἔχουσιν εἶναι μίαν, δυνάμει δὲ

πλείους, ὁμοίως δὲ καὶ τὴν αἰσθητικήν· φαίνεται γὰρ

5 ἔχοντα αἴσθησιν τὰ διαιρούμενα αὐτῶν. ἀλλὰ πρὸς τὸ σῴζεσθαι

τὴν φύσιν, τὰ μὲν φυτὰ δύναται, ταῦτα δ' οὐ δύναται

διὰ τὸ μὴ ἔχειν ὄργανα πρὸς σωτηρίαν, ἐνδεᾶ τ' εἶναι

τὰ μὲν τοῦ ληψομένου τὰ δὲ τοῦ δεξομένου τὴν τροφήν,

τὰ δ' ἄλλων τε καὶ τούτων ἀμφοτέρων. ἐοίκασι γὰρ τὰ

10 τοιαῦτα τῶν ζῴων πολλοῖς ζῴοις συμπεφυκόσιν (τὰ δ' ἄριστα

συνεστηκότα τοῦτ' οὐ πάσχει τῶν ζῴων διὰ τὸ εἶναι τὴν

φύσιν αὐτῶν ὡς ἐνδέχεται μάλιστα μίαν). διὸ καὶ μικρὰν

αἴσθησιν ἔνια ποιεῖ διαιρούμενα τῶν μορίων ὅτι ἔχει τι ψυχικὸν

πάθος· χωριζομένων γὰρ τῶν σπλάγχνων ποιεῖται

15 κίνησιν, οἷον καὶ αἱ χελῶναι τῆς καρδίας ἀφῃρημένης.

1In this respect, however, plants and insects are alike.
It is true that the nutritive soul, in beings possessing it, while actually single must be potentially plural. And it is too with the principle of sensation, for 5evidently the divided segments of these animals have sensation. They are unable, however, to preserve their constitution, as plants can, not possessing the organs on which the continuance of life depends, for some lack the means for seizing, others for receiving their food; or again they may be destitute of other organs as well.
10Divisible animals are like a number of animals grown together, but animals of superior construction behave differently because their constitution is a unity of the highest possible kind. Hence some of the organs on division display slight sensitiveness because they retain some psychical susceptibility; 15the animals continue to move after the vitals have been abstracted: tortoises, for example, do so even after the heart has been removed.

Chapter 3 (468b16–469a26)

Ἔτι δὲ ἐπί τε τῶν φυτῶν δῆλον καὶ ἐπὶ τῶν ζῴων,

τῶν μὲν φυτῶν τήν τ' ἐκ τῶν σπερμάτων γένεσιν ἐπισκοποῦσι

καὶ τὰς ἐμφυτείας τε καὶ τὰς ἀποφυτείας. ἥ τε γὰρ

ἐκ τῶν σπερμάτων γένεσις συμβαίνει πᾶσιν ἐκ τοῦ μέσου (διθύρων

20 γὰρ ὄντων πάντων, ᾗ συμπέφυκεν καὶ τὸ μέσον

ἔστιν ἑκατέρου τῶν μορίων, ἐντεῦθεν ὅ τε καυλὸς

ἐκφύεται καὶ ἡ ῥίζα τῶν φυομένων, ἡ δ' ἀρχὴ τὸ μέσον

αὐτῶν ἐστιν), ἔν τε ταῖς ἐμφυτείαις καὶ ταῖς ἀποφυτείαις

μάλιστα συμβαίνει τοῦτο περὶ τοὺς ὄζους· ἔστι γὰρ ἀρχή τις

25 ὁ ὄζος τοῦ κλάδου, ἅμα δὲ καὶ μέσον, ὥστε ἢ τοῦτο ἀφαιροῦσιν

ἢ εἰς τοῦτο ἐμβάλλουσιν, ἵνα ἢ ὁ κλάδος ἢ αἱ ῥίζαι ἐκ

τούτου γίνωνται, ὡς οὔσης τῆς ἀρχῆς ἐκ τοῦ μέσου κλάδου καὶ

ῥίζης. καὶ τῶν ζῴων τῶν ἐναίμων ἡ καρδία γίνεται πρῶτον·

τοῦτο δὲ δῆλον ἐξ ὧν ἐν τοῖς ἐνδεχομένοις ἔτι γινομένοις

30 ἰδεῖν τεθεωρήκαμεν. ὥστε καὶ ἐν τοῖς ἀναίμοις ἀναγκαῖον τὸ

ἀνάλογον τῇ καρδίᾳ γίνεσθαι πρῶτον. ἡ δὲ καρδία ὅτι ἐστὶν

ἀρχή, τῶν φλεβῶν ἐν τοῖς περὶ τὰ Πέρη τῶν ζῴων εἴρηται

16The same phenomenon is evident both in plants and in animals, and in plants we note it both in their propagation by seed and in grafts and cuttings. Genesis from seeds always starts from the middle. 20All seeds are bivalvular, and the place of junction is situated at the point of attachment (to the plant), an intermediate part belonging to both halves. It is from this part that both root and stem of growing things emerge; the starting-point is in a central position between them. In the case of grafts and cuttings this is particularly true of the buds; for the bud is in a way 25the starting-point of the branch, but at the same time it is in a central position. Hence it is either this that is cut off, or into this that the new shoot is inserted, when we wish either a new branch or a new root to spring from it; which proves that the point of origin in growth is intermediate between stem and root.
Likewise in sanguineous animals the heart is the first organ developed; this is evident from what has been observed in those cases where observation of their growth is possible. 30Hence in bloodless animals also what corresponds to the heart must develop first.

469a

1 πρότερον· καὶ ὅτι τὸ αἷμα τοῖς ἐναίμοις ἐστὶ τελευταία τροφή,

ἐξ οὗ γίνεται τὰ μόρια. φανερὸν τοίνυν ὅτι μίαν μέν

τινα ἐργασίαν ἡ τοῦ στόματος λειτουργεῖ δύναμις, ἑτέραν δ'

ἡ τῆς κοιλίας, περὶ τὴν τροφήν, ἡ δὲ καρδία κυριωτάτη, καὶ

5 τὸ τέλος ἐπιτίθησιν. ὥστ' ἀνάγκη καὶ τῆς αἰσθητικῆς καὶ

τῆς θρεπτικῆς ψυχῆς ἐν τῇ καρδίᾳ τὴν ἀρχὴν εἶναι τοῖς

ἐναίμοις· τὰ γὰρ τῶν ἄλλων μορίων ἔργα περὶ τὴν τροφὴν

τοῦ ταύτης ἔργου χάριν ἐστί· δεῖ μὲν γὰρ τὸ κύριον πρὸς τὸ οὗ

ἕνεκα διατελεῖν, ἀλλ' οὐκ ἐν τοῖς τούτου ἕνεκα, οἷον ἰατρὸς

10 πρὸς τὴν ὑγίειαν. ἀλλὰ μὴν τό γε κύριον τῶν αἰσθήσεων

ἐν ταύτῃ τοῖς ἐναίμοις πᾶσιν· ἐν τούτῳ γὰρ ἀναγκαῖον εἶναι

τὸ πάντων τῶν αἰσθητηρίων κοινὸν αἰσθητήριον. δύο δὲ φανερῶς

ἐνταῦθα συντεινούσας ὁρῶμεν, τήν τε γεῦσιν καὶ τὴν

ἁφήν, ὥστε καὶ τὰς ἄλλας ἀναγκαῖον· ἐν τούτῳ μὲν γὰρ

15 τοῖς ἄλλοις αἰσθητηρίοις ἐνδέχεται ποιεῖσθαι τὴν κίνησιν,

ταῦτα δ' οὐδὲν συντείνει πρὸς τὸν ἄνω τόπον. χωρὶς δὲ τούτων,

εἰ τὸ ζῆν ἐν τούτῳ τῷ μορίῳ πᾶσίν ἐστι, δῆλον ὅτι καὶ

τὴν αἰσθητικὴν ἀρχὴν ἀναγκαῖον· ᾗ μὲν γὰρ ζῷον, ταύτῃ

καὶ ζῆν φαμεν, ᾗ δ' αἰσθητικόν, ταύτῃ τὸ σῶμα ζῷον εἶναι

20 λέγομεν. διὰ τί δ' αἱ μὲν τῶν αἰσθήσεων φανερῶς συντείνουσι

πρὸς τὴν καρδίαν, αἱ δ' εἰσὶν ἐν τῇ κεφαλῇ (διὸ καὶ

δοκεῖ τισιν αἰσθάνεσθαι τὰ ζῷα διὰ τὸν ἐγκέφαλον), τὸ

αἴτιον τούτων ἐν ἑτέροις εἴρηται χωρίς. κατὰ μὲν οὖν τὰ φαινόμενα

δῆλον ἐκ τῶν εἰρημένων ὅτι ἐν τούτῳ τε καὶ ἐν τῷ

25 μέσῳ τοῦ σώματος τῶν τριῶν μορίων ἥ τε τῆς αἰσθητικῆς

ψυχῆς ἀρχή ἐστι καὶ ἡ τῆς αὐξητικῆς καὶ θρεπτικῆς·

1We have already asserted in our treatise on The Parts of Animals that it is from the heart that the veins issue, and that in sanguineous animals the blood is the final nutriment from which the members are formed. Hence it is clear that there is one function in nutrition which the mouth has the faculty of performing, and a different one appertaining to the stomach. But it is the heart that has supreme control, exercising an additional and completing function. 5Hence in sanguineous animals the source both of the sensitive and of the nutritive soul must be in the heart, for the functions relative to nutrition exercised by the other parts are ancillary to the activity of the heart. It is the part of the dominating organ to achieve the final result, as of the physician's efforts to be directed towards health, and not to be occupied with subordinate offices.
10Certainly, however, all saguineous animals have the supreme organ of the sensefaculties in the heart, for it is here that we must look for the common sensorium belonging to all the sense-organs. These in two cases, taste and touch, can be clearly seen to extend to the heart, and hence the others also must lead to it, for in it 15the other organs may possibly initiate changes, whereas with the upper region of the body taste and touch have no connexion. Apart from these considerations, if the life is always located in this part, evidently the principle of sensation must be situated there too, for it is qua animal that an animal is said to be a living thing, and it is called animal because endowed with sensation. 20Elsewhere in other works we have stated the reasons why some of the sense-organs are, as is evident, connected with the heart, while others are situated in the head.
(It is this fact that causes some people to think that it is 25in virtue of the brain that the function of perception belongs to animals.)

Chapter 4 (469a27–469b20)

κατὰ δὲ τὸν λόγον, ὅτι τὴν φύσιν ὁρῶμεν ἐν πᾶσιν

ἐκ τῶν δυνατῶν ποιοῦσαν τὸ κάλλιστον· ἐν τῷ μέσῳ δὲ τῆς

30 οὐσίας τῆς ἀρχῆς οὔσης ἑκατέρας μάλιστα ἂν ἀποτελοῖ τῶν

μορίων ἑκάτερον τὸ αὑτοῦ ἔργον, τό τε κατεργαζόμενον τὴν

ἐσχάτην τροφὴν καὶ τὸ δεκτικόν· πρὸς ἑκατέρῳ γὰρ αὐτῶν

οὕτως ἔσται, καὶ ἔστιν ἡ τοῦ τοιούτου μέσου χώρα ἄρχοντος

27Thus if, on the one hand, we look to the observed facts, what we have said makes it clear that the source of the sensitive soul, together with that connected with growth and nutrition, is situated in this organ and in the central one of the three divisions of the body. But it follows by deduction also; for we see that in every case, when several results are open to her, Nature always brings to pass the best. 30Now if both principles are located in the midst of the substance, the two parts of the body, viz.

469b

1 χώρα. ἔτι τὸ χρώμενον καὶ ᾧ χρῆται τὸ χρώμενον δεῖ διαφέρειν

(ὥσπερ δὲ τὴν δύναμιν, οὕτως, ἂν ἐνδέχηται, καὶ τὸν τόπον),

ὥσπερ οἵ τ' αὐλοὶ καὶ τὸ κινοῦν τοὺς αὐλούς, ἡ χείρ. εἴπερ

οὖν τὸ ζῷον ὥρισται τῷ τὴν αἰσθητικὴν ἔχειν ψυχήν, τοῖς

5 μὲν ἐναίμοις ἀναγκαῖον ἐν τῇ καρδίᾳ ταύτην ἔχειν τὴν ἀρχήν,

τοῖς δ' ἀναίμοις ἐν τῷ ἀνάλογον μορίῳ. πάντα δὲ τὰ

μόρια καὶ πᾶν τὸ σῶμα τῶν ζῴων ἔχει τινὰ σύμφυτον

θερμότητα φυσικήν· διὸ ζῶντα μὲν φαίνεται θερμά, τελευτῶντα

δὲ καὶ στερισκόμενα τοῦ ζῆν τοὐναντίον. ἀναγκαῖον δὴ

10 ταύτης τὴν ἀρχὴν τῆς θερμότητος ἐν τῇ καρδίᾳ τοῖς ἐναίμοις

εἶναι, τοῖς δ' ἀναίμοις ἐν τῷ ἀνάλογον· ἐργάζεται γὰρ

καὶ πέττει τῷ φυσικῷ θερμῷ τὴν τροφὴν πάντα, μάλιστα

δὲ τὸ κυριώτατον. διὸ τῶν μὲν ἄλλων μορίων ψυχομένων

ὑπομένει τὸ ζῆν, τοῦ δ' ἐν ταύτῃ φθείρεται πάμπαν, διὰ τὸ

15 τὴν ἀρχὴν ἐντεῦθεν τῆς θερμότητος ἠρτῆσθαι πᾶσι, καὶ τῆς

ψυχῆς ὥσπερ ἐμπεπυρευμένης ἐν τοῖς μορίοις τούτοις, τῶν

μὲν ἀναίμων ἐν τῷ ἀνάλογον, ἐν δὲ τῇ καρδίᾳ τῶν ἐναίμων.

ἀνάγκη τοίνυν ἅμα τό τε ζῆν ὑπάρχειν καὶ τὴν τοῦ θερμοῦ

τούτου σωτηρίαν, καὶ τὸν καλούμενον θάνατον εἶναι τὴν

20 τούτου φθοράν.

1that which elaborates and that which receives the nutriment in its final form will best perform their appropriate function; for the soul will then be close to each, and the central situation which it will, as such, occupy is the position of a dominating power.
Further, that which employs an instrument and the instrument it employs must be distinct (and must be spatially diverse too, if possible, as in capacity), just as the flute and that which plays it-the hand-are diverse. Thus if animal is defined by the possession of sensitive soul, 5this soul must in the sanguineous animals be in the heart, and, in the bloodless ones, in the corresponding part of their body. But in animals all the members and the whole body possess some connate warmth of constitution, and hence when alive they are observed to be warm, but when dead and deprived of life they are the opposite. Indeed, 10the source of this warmth must be in the heart in sanguineous animals, and in the case of bloodless animals in the corresponding organ, for, though all parts of the body by means of their natural heat elaborate and concoct the nutriment, the governing organ takes the chief share in this process. Hence, though the other members become cold, life remains; but when the warmth here is quenched, death always ensues, 15because the source of heat in all the other members depends on this, and the soul is, as it were, set aglow with fire in this part, which in sanguineous animals is the heart and in the bloodless order the analogous member. Hence, of necessity, life must be coincident with the maintenance of heat, 20and what we call death is its destruction.

Chapter 5 (469b21–470a18)

Ἀλλὰ μὴν πυρός γε δύο ὁρῶμεν φθοράς, μάρανσίν τε

καὶ σβέσιν. καλοῦμεν δὲ τὴν μὲν ὑφ' αὑτοῦ μάρανσιν, τὴν δ'

ὑπὸ τῶν ἐναντίων σβέσιν, [τὴν μὲν γήρᾳ, τὴν δὲ βίαιον,] συμβαίνει

δ' ἀμφοτέρας διὰ ταὐτὸ γίνεσθαι τὰς φθοράς· ὑπολειπούσης

25 γὰρ τῆς τροφῆς, οὐ δυναμένου λαμβάνειν τοῦ θερμοῦ

τὴν τροφήν, φθορὰ γίνεται τοῦ πυρός. τὸ μὲν γὰρ ἐναντίον

παῦον τὴν πέψιν κωλύει τρέφεσθαι· ὁτὲ δὲ μαραίνεσθαι

συμβαίνει, πλείονος ἀθροιζομένου θερμοῦ διὰ τὸ μὴ ἀναπνεῖν

μηδὲ καταψύχεσθαι· ταχὺ γὰρ καὶ οὕτω καταναλίσκει

30 τὴν τροφὴν πολὺ συναθροιζόμενον τὸ θερμόν, καὶ φθάνει

καταναλίσκον πρὶν ἐπιστῆναι τὴν ἀναθυμίασιν. διόπερ οὐ μόνον

μαραίνεται τὸ ἔλαττον παρὰ τὸ πλεῖον πῦρ, ἀλλὰ καὶ

αὐτὴ καθ' αὑτὴν ἡ τοῦ λύχνου φλὸξ ἐντιθεμένη πλείονι φλογὶ

21However, it is to be noticed that there are two ways in which fire ceases to exist; it may go out either by exhaustion or by extinction. That which is self-caused we call exhaustion, that due to its opposites extinction.
[The former is that due to old age, the latter to violence.] But either of these ways in which fire ceases to be may be brought about by the same cause, 25for, when there is a deficiency of nutriment and the warmth can obtain no maintenance, the fire fails; and the reason is that the opposite, checking digestion, prevents the fire from being fed. But in other cases the result is exhaustion,-when the heat accumulates excessively owing to lack of respiration and of refrigeration. For in this case 30what happens is that the heat, accumulating in great quantity, quickly uses up its nutriment and consumes it all before more is sent up by evaporation.

470a

1 κατακαίεται, καθάπερ ὁτιοῦν ἄλλο τῶν καυστῶν. αἴτιον δ' ὅτι

τὴν μὲν οὖσαν ἐν τῇ φλογὶ τροφὴν φθάνει λαμβάνουσα ἡ

μείζων φλὸξ πρὶν ἐπελθεῖν ἑτέραν, τὸ δὲ πῦρ ἀεὶ διατελεῖ

γινόμενον καὶ ῥέον ὥσπερ ποταμός, ἀλλὰ λανθάνει διὰ τὸ

5 τάχος. δῆλον τοίνυν ὡς εἴπερ δεῖ σῴζεσθαι τὸ θερμόν (τοῦτο

δ' ἀναγκαῖον, εἴπερ μέλλει ζῆν), δεῖ γίνεσθαί τινα τοῦ θερμοῦ

τοῦ ἐν τῇ ἀρχῇ κατάψυξιν. παράδειγμα δὲ τούτου λαβεῖν

ἔστι τὸ συμβαῖνον ἐπὶ τῶν καταπνιγομένων ἀνθράκων· ἂν

μὲν γὰρ ὦσι περιπεπωμασμένοι τῷ καλουμένῳ πνιγεῖ συνεχῶς,

10 ἀποσβέννυνται ταχέως· ἂν δὲ παρ' ἄλληλά τις ποιῇ

πυκνὰ τὴν ἀφαίρεσιν καὶ τὴν ἐπίθεσιν, μένουσι πεπυρωμένοι

πολὺν χρόνον. ἡ δ' ἔγκρυψις σῴζει τὸ πῦρ· οὔτε γὰρ ἀποπνεῖν

κωλύεται, διὰ μανότητα τῆς τέφρας, ἀντιφράττει τε

τῷ πέριξ ἀέρι πρὸς τὸ μὴ σβεννύναι, τῷ πλήθει τῆς ἐνυπαρχούσης

15 αὐτῷ θερμότητος. ἀλλὰ περὶ μὲν τῆς αἰτίας ταύτης,

ὅτι τὸ ἐναντίον συμβαίνει τῷ ἐγκρυπτομένῳ καὶ καταπνιγομένῳ

πυρί (τὸ μὲν γὰρ μαραίνεται, τὸ δὲ διαμένει

πλείω χρόνον), εἴρηται ἐν τοῖς προβλήμασιν.

1Hence not only is a smaller fire readily put out by a large one, but of itself the candle flame is consumed when inserted in a large blaze just as is the case with any other combustible. The reason is that the nutriment in the flame is seized by the larger one before fresh fuel can be added, for fire is ever coming into being and rushing just like a river, but so speedily as to elude observation.
5Clearly therefore, if the bodily heat must be conserved (as is necessary if life is to continue), there must be some way of cooling the heat resident in the source of warmth. Take as an illustration what occurs when coals are confined in a brazier. If they are kept covered up continuously by the so-called 'choker', 10they are quickly extinguished, but, if the lid is in rapid alternation lifted up and put on again they remain glowing for a long time. Banking up a fire also keeps it in, for the ashes, being porous, do not prevent the passage of air, and again they enable it to resist extinction by the surrounding air by means of the supply of heat which it possesses. 15However, we have stated in The Problems the reasons why these operations, namely banking up and covering up a fire, have the opposite effects (in the one case the fire goes out, in the other it continues alive for a considerable time).

Chapter 6 (470a19–470b5)

Ἐπεὶ δὲ πᾶν ζῶν ἔχει ψυχήν, αὕτη δ' οὐκ ἄνευ φυσικῆς

20 ὑπάρχει θερμότητος, ὥσπερ εἴπομεν, τοῖς μὲν φυτοῖς

ἡ διὰ τῆς τροφῆς καὶ τοῦ περιέχοντος ἱκανὴ γίνεται

βοήθεια πρὸς τὴν τοῦ φυσικοῦ θερμοῦ σωτηρίαν. καὶ γὰρ ἡ

τροφὴ ποιεῖ κατάψυξιν εἰσιοῦσα, καθάπερ καὶ τοῖς ἀνθρώποις

τὸ πρῶτον προσενεγκαμένοις, αἱ δὲ νηστεῖαι θερμαίνουσι

25 καὶ δίψας ποιοῦσιν· ἀκίνητος γὰρ ὢν ὁ ἀὴρ ἀεὶ θερμαίνεται,

τῆς δὲ τροφῆς εἰσιούσης καταψύχεται κινούμενος, ἕως ἂν

λάβῃ τὴν πέψιν. ἐὰν δὲ τὸ περιέχον ὑπερβάλλῃ ψυχρότητι

διὰ τὴν ὥραν, ἰσχυρῶν γινομένων πάγων, ἐξαυαίνεται

ἡ τοῦ θερμοῦ ἰσχύς, ἂν δὲ συμβαίνῃ καύματα καὶ μὴ δύνηται

30 τὸ σπώμενον ἐκ τῆς γῆς ὑγρὸν καταψύχειν, φθείρεται

μαραινόμενον τὸ θερμόν, καὶ λέγεται σφακελίζειν καὶ

ἀστρόβλητα γίνεσθαι τὰ δένδρα περὶ τοὺς καιροὺς τούτους. διὸ

καὶ γένη τινὰ λίθων ταῖς ῥίζαις ὑποβάλλουσι καὶ ὕδωρ ἐν

19Everything living has soul, and it, as we have said, cannot exist without the presence of 20heat in the constitution. In plants the natural heat is sufficiently well kept alive by the aid which their nutriment and the surrounding air supply. For the food has a cooling effect [as it enters, just as it has in man] when first it is taken in, whereas abstinence from food produces heat and thirst. 25The air, if it be motionless, becomes hot, but by the entry of food a motion is set up which lasts until digestion is completed and so cools it. If the surrounding air is excessively cold owing to the time of year, there being severe frost, plants shrivel, or if, in the extreme heats of summer 30the moisture drawn from the ground cannot produce its cooling effect, the heat comes to an end by exhaustion. Trees suffering at such seasons are said to be blighted or star-stricken. Hence the practice of laying beneath the roots stones of certain species or water in pots, for the purpose of cooling the roots of the plants.

470b

1 ἀγγείοις, ὅπως αἱ ῥίζαι ψύχωνται τῶν φυτῶν. τῶν δὲ

ζῴων ἐπεὶ τὰ μέν ἐστιν ἔνυδρα τὰ δ' ἐν τῷ ἀέρι ποιεῖται

τὴν δίαιταν, ἐκ τούτων καὶ διὰ τούτων πορίζεται τὴν κατάψυξιν,

τὰ μὲν τῷ ὕδατι τὰ δὲ τῷ ἀέρι. τίνα δὲ τρόπον

5 καὶ πῶς, λεκτέον ἐπιστήσασι τὸν λόγον μᾶλλον.

1Some animals pass their life in the water, others in the air, and therefore these media furnish the source and means of refrigeration, water in the one case, air in the other. We must proceed-and it will require further application on our part-to 5give an account of the way and manner in which this refrigeration occurs.

Chapter 7 (470b6–27)

Περὶ γὰρ ἀναπνοῆς ὀλίγοι μέν τινες τῶν πρότερον φυσικῶν

εἰρήκασιν· τίνος μέντοι χάριν ὑπάρχει τοῖς ζῴοις,

οἱ μὲν οὐδὲν ἀπεφήναντο, οἱ δὲ εἰρήκασι μέν, οὐ καλῶς δ'

εἰρήκασιν ἀλλ' ἀπειροτέρως τῶν συμβαινόντων. ἔτι δὲ πάντα

10 τὰ ζῷά φασιν ἀναπνεῖν· τοῦτο δ' οὐκ ἔστιν ἀληθές. ὥστ' ἀναγκαῖον

περὶ τούτων πρῶτον ἐπελθεῖν, ὅπως μὴ δοκῶμεν ἀπόντων

κενὴν κατηγορεῖν. ὅτι μὲν οὖν ὅσα πνεύμονα ἔχει τῶν

ζῴων ἀναπνεῖ πάντα, φανερόν. ἀλλὰ καὶ τούτων αὐτῶν

ὅσα μὲν ἄναιμον ἔχει τὸν πνεύμονα καὶ σομφὸν ἧττον

15 δέονται τῆς ἀναπνοῆς· διὸ πολὺν χρόνον ἐν τοῖς ὕδασι δύνανται

διαμένειν παρὰ τὴν τοῦ σώματος ἰσχύν. τὸν δὲ πνεύμονα

σομφὸν ἔχει πάντα τὰ ᾠοτοκοῦντα, οἷον τὸ τῶν βατράχων

γένος. ἔτι δὲ αἱ ἑμύδες τε καὶ χελῶναι πολὺν

χρόνον μένουσιν ἐν τοῖς ὑγροῖς· ὁ γὰρ πνεύμων ὀλίγην ἔχει

20 θερμότητα (ὀλίγαιμον γὰρ ἔχουσιν αὐτόν)· ἐμφυσώμενος οὖν

αὐτὸς τῇ κινήσει καταψύχει καὶ ποιεῖ διαμένειν πολὺν

χρόνον. ἐὰν μέντοι βιάζηταί τις λίαν κατέχων πολὺν χρόνον,

ἀποπνίγονται πάντα· οὐδὲν γὰρ τῶν τοιούτων δέχεται τὸ

ὕδωρ ὥσπερ οἱ ἰχθύες. τὰ δ' ἔναιμον ἔχοντα πνεύμονα

25 πάντα μᾶλλον δεῖται τῆς ἀναπνοῆς διὰ τὸ πλῆθος τῆς

θερμότητος· τῶν δ' ἄλλων ὅσα μὴ ἔχει πνεύμονα οὐθὲν

ἀναπνεῖ.

6A few of the previous physical philosophers have spoken of respiration.
The reason, however, why it exists in animals they have either not declared or, when they have, their statements are not correct and show a comparative lack of acquaintance with the facts. 10Moreover they assert that all animals respire-which is untrue. Hence these points must first claim our attention, in order that we may not be thought to make unsubstantiated charges against authors no longer alive.
First then, it is evident that all animals with lungs breathe, but in some cases breathing animals have a bloodless and spongy lung, and then 15there is less need for respiration. These animals can remain under water for a time, which relatively to their bodily strength, is considerable.
All oviparous animals, e.g. the frog-tribe, have a spongy lung. Also hemydes and tortoises can remain for a long time immersed in water; for their lung, containing little blood, has not much heat. 20Hence, when once it is inflated, it itself, by means of its motion, produces a cooling effect and enables the animal to remain immersed for a long time. Suffocation, however, always ensues if the animal is forced to hold its breath for too long a time, for none of this class take in water in the way fishes do. On the other hand, animals which have the lung charged with blood 25have greater need of respiration on account of the amount of their heat, while none at all of the others which do not possess lungs breathe.

Chapter 8 (470b28–471a19)

Δημόκριτος μὲν οὖν ὁ Ἀβδηρίτης καί τινες ἄλλοι τῶν

περὶ τῆς ἀναπνοῆς εἰρηκότων οὐδὲν περὶ τῶν ἄλλων διωρίκασι

30 ζῴων, ἐοίκασι μέντοι λέγειν ὡς πάντων ἀναπνεόντων· Ἀναξαγόρας

δὲ καὶ Διογένης, πάντα φάσκοντες ἀναπνεῖν, περὶ

τῶν ἰχθύων καὶ τῶν ὀστρέων λέγουσι τίνα τρόπον ἀναπνέουσιν,

καί φησιν Ἀναξαγόρας μέν, ὅταν ἀφῶσι τὸ ὕδωρ διὰ τῶν

28Democritus of Abdera and certain others who have treated of respiration, while saying nothing definite about the lungless animals, 30nevertheless seem to speak as if all breathed. But Anaxagoras and Diogenes both maintain that all breathe, and state the manner in which fishes and oysters respire.
Anaxagoras says that when fishes discharge water through their gills, air is formed in the mouth, for there can be no vacuum, and that it is by drawing in this that they respire.

471a

1 βραγχίων, τὸν ἐν τῷ στόματι γινόμενον ἀέρα ἕλκοντας ἀναπνεῖν

τοὺς ἰχθῦς· οὐ γὰρ εἶναι κενὸν οὐδέν· Διογένης δ' ὅταν

ἀφῶσι τὸ ὕδωρ διὰ τῶν βραγχίων, ἐκ τοῦ περὶ τὸ στόμα

περιεστῶτος ὕδατος ἕλκειν τῷ κενῷ τῷ ἐν τῷ στόματι τὸν

5 ἀέρα, ὡς ἐνόντος ἐν τῷ ὕδατι ἀέρος. ταῦτα δ' ἐστὶν ἀδύνατα.

πρῶτον μὲν γὰρ τὸ ἥμισυ τοῦ πράγματος ἀφαιροῦσι,

διὰ τὸ τὸ κοινὸν ἐπὶ θατέρου λέγεσθαι μόνον. ἀναπνοὴ γὰρ

καλεῖται, ταύτης δὲ τὸ μέν ἐστιν εἰσπνοή, τὸ δ' ἐκπνοή, περὶ

ἧς οὐθὲν λέγουσι, τίνα τρόπον ἐκπνέουσι τὰ τοιαῦτα τῶν ζῴων.

10 οὐδ' ἐνδέχεται αὐτοῖς εἰπεῖν· ὅταν γὰρ ἀναπνεύσωσι, ταύτῃ

ᾗ ἀνέπνευσαν πάλιν δεῖ ἐκπνεῖν, καὶ τοῦτο ποιεῖν ἀεὶ παραλλάξ,

ὥστε συμβαίνει ἅμα δέχεσθαι τὸ ὕδωρ κατὰ τὸ

στόμα καὶ ἐκπνεῖν. ἀνάγκη δ' ἀπαντῶντα ἐμποδίζειν θάτερον

θατέρῳ. εἶτα ὅταν ἀφῶσι τὸ ὕδωρ, τότε ἐκπνέουσι κατὰ

15 τὸ στόμα ἢ κατὰ τὰ βράγχια, ὥστε συμβαίνει ἅμα ἐκπνεῖν

καὶ ἀναπνεῖν· τότε γάρ φασιν αὐτὸ ἀναπνεῖν. ἅμα

δ' ἀναπνεῖν καὶ ἐκπνεῖν ἀδύνατον. ὥστ' εἰ ἀνάγκη τὰ ἀναπνέοντα

ἐκπνεῖν καὶ εἰσπνεῖν, ἐκπνεῖν δὲ μὴ ἐνδέχεται μηδὲν

αὐτῶν, φανερὸν ὡς οὐδ' ἀναπνεῖ αὐτῶν οὐδέν.

1Diogenes' statement is that, when they discharge water through their gills, they suck the air out of the water surrounding the mouth by means of the vacuum formed in the mouth, 5for he believes there is air in the water.
But these theories are untenable. Firstly, they state only what is the common element in both operations and so leave out the half of the matter. For what goes by the name of respiration consists, on the one hand, of inhalation, and, on the other, of the exhalation of breath; but, about the latter they say nothing, nor do they describe how such animals emit their breath. 10Indeed, explanation is for them impossible for, when the creatures respire, they must discharge their breath by the same passage as that by which they draw it in, and this must happen in alternation.
Hence, as a result, they must take the water into their mouth at the same time as they breathe out. But the air and the water must meet and obstruct each other. Further, when they discharge the water they must emit their breath 15by the mouth or the gills, and the result will be that they will breathe in and breathe out at the same time, for it is at that moment that respiration is said to occur. But it is impossible that they should do both at the same time. Hence, if respiring creatures must both exhale and inhale the air, and if none of these animals can breathe out, evidently none can respire at all.

Chapter 9 (471a20–471b29)

20 Ἔτι δὲ τὸ φάναι τὸν ἀέρα ἕλκειν ἐκ τοῦ στόματος ἢ

ἐκ τοῦ ὕδατος διὰ τοῦ στόματος ἀδύνατον· οὐ γὰρ ἔχουσιν

ἀρτηρίαν διὰ τὸ πνεύμονα μὴ ἔχειν, ἀλλ' εὐθὺς ἡ κοιλία

πρὸς τῷ στόματί ἐστιν, ὥστ' ἀναγκαῖον τῇ κοιλίᾳ ἕλκειν. τοῦτο

δὲ κἂν τἆλλα ἐποίει ζῷα· νῦν δὲ οὐ ποιοῦσιν. κἂν ἐκεῖνα δ'

25 ἔξω τοῦ ὑγροῦ ὄντα ἐπιδήλως ἂν αὐτὸ ἐποίει· φαίνεται δ' οὐ

ποιοῦντ' αὐτό. ἔτι πάντων τῶν ἀναπνεόντων καὶ ἑλκόντων τὸ

πνεῦμα ὁρῶμεν γινομένην τινὰ κίνησιν τοῦ μορίου τοῦ ἕλκοντος,

ἐπὶ δὲ τῶν ἰχθύων οὐ συμβαῖνον· οὐθὲν γὰρ φαίνονται κινοῦντες

τῶν περὶ τὴν κοιλίαν ἀλλ' ἢ τὰ βράγχια μόνον,

30 καὶ ἐν τῷ ὑγρῷ καὶ εἰς τὸ ξηρὸν ἐμπεσόντες, ὅταν ἀσπαρίζωσιν.

ἔτι ὅταν ἀποθνήσκῃ πνιγόμενα ἐν τοῖς ὑγροῖς πάντα

20Further, the assertion that they draw in air out of the mouth or out of the water by means of the mouth is an impossibility, for, not having a lung, they have no windpipe; rather the stomach is closely juxtaposed to the mouth, so that they must do the sucking with the stomach. But in that case the other animals would do so also, which is not the truth; and 25the water-animals also would be seen to do it when out of the water, whereas quite evidently they do not. Further, in all animals that respire and draw breath there is to be observed a certain motion in the part of the body which draws in the air, but in the fishes this does not occur. Fishes do not appear to move any of the parts in the region of the stomach, except the gills alone, 30and these move both when they are in the water and when they are thrown on to dry land and gasp.

471b

1 τὰ ἀναπνέοντα, γίνονται πομφόλυγες τοῦ πνεύματος ἐξιόντος

βιαίως, οἷον ἐάν τις βιάζηται χελώνας ἢ βατράχους

ἤ τι ἄλλο τῶν τοιούτων γενῶν· ἐπὶ δὲ τῶν ἰχθύων οὐ συμβαίνει

πειρωμένοις πάντα τρόπον, ὡς οὐκ ἐχόντων πνεῦμα

5 θύραθεν οὐθέν. ὅν τε τρόπον λέγουσι γίνεσθαι τὴν ἀναπνοὴν

αὐτοῖς, ἐνδέχεται καὶ τοῖς ἀνθρώποις οὖσιν ἐν τῷ ὑγρῷ

συμβαίνειν· εἰ γὰρ καὶ οἱ ἰχθύες ἕλκουσιν ἐκ τοῦ πέριξ

ὕδατος τῷ στόματι, διὰ τί τοῦτο οὐκ ἂν ποιοῖμεν καὶ οἱ

ἄνθρωποι καὶ τἆλλα ζῷα; καὶ τὸν ἐκ τοῦ στόματος δ' ἂν

10 ἕλκοιεν ὁμοίως τοῖς ἰχθύσιν. ὥστ' εἴπερ κἀκεῖνα ἦν δυνατά,

καὶ ταῦτ' ἂν ἦν· ἐπεὶ δ' οὐκ ἔστι, δῆλον ὡς οὐδ' ἐπ' ἐκείνων

ἐστίν. πρὸς δὲ τούτοις διὰ τίν' αἰτίαν ἐν τῷ ἀέρι ἀποθνήσκουσι

καὶ φαίνονται ἀσπαρίζοντα ὥσπερ τὰ πνιγόμενα, εἴπερ

ἀναπνέουσιν; οὐ γὰρ δὴ τροφῆς γε ἐνδείᾳ τοῦτο πάσχουσιν.

15 ἣν γὰρ λέγει Διογένης αἰτίαν, εὐήθης· φησὶ γὰρ ὅτι τὸν

ἀέρα πολὺν ἕλκουσι λίαν ἐν τῷ ἀέρι, ἐν δὲ τῷ ὕδατι μέτριον,

καὶ διὰ τοῦτ' ἀποθνήσκειν. καὶ γὰρ ἐπὶ τῶν πεζῶν

ἔδει δυνατὸν εἶναι τοῦτο συμβαίνειν· νῦν δ' οὐδὲν τῷ σφόδρα

ἀναπνεῦσαι ἀποπνίγεται πεζὸν ζῷον. ἔτι δ' εἰ πάντα ἀναπνεῖ,

20 δῆλον ὅτι καὶ τὰ ἔντομα τῶν ζῴων ἀναπνεῖ· φαίνεται

δ' αὐτῶν πολλὰ διατεμνόμενα ζῆν, οὐ μόνον εἰς δύο

μέρη ἀλλὰ καὶ εἰς πλείω, οἷον αἱ καλούμεναι σκολόπενδραι·

ἃ πῶς ἢ τίνι ἐνδέχεται ἀναπνεῖν; αἴτιον δὲ μάλιστα

τοῦ μὴ λέγεσθαι περὶ αὐτῶν καλῶς τό τε τῶν μορίων ἀπείρους

25 εἶναι τῶν ἐντός, καὶ τὸ μὴ λαμβάνειν ἕνεκά τινος τὴν

φύσιν πάντα ποιεῖν· ζητοῦντες γὰρ τίνος ἕνεκα ἡ ἀναπνοὴ

τοῖς ζῴοις ὑπάρχει, καὶ ἐπὶ τῶν μορίων τοῦτ' ἐπισκοποῦντες,

οἷον ἐπὶ βραγχίων καὶ πνεύμονος, εὗρον ἂν θᾶττον τὴν

αἰτίαν.

1Moreover, always when respiring animals are killed by being suffocated in water, bubbles are formed of the air which is forcibly discharged, as happens, e.g. when one forces a tortoise or a frog or any other animal of a similar class to stay beneath water. But with fishes this result never occurs, in whatsoever way we try to obtain it, since they do not contain air drawn from an external source.
5Again, the manner of respiration said to exist in them might occur in the case of men also when they are under water. For if fishes draw in air out of the surrounding water by means of their mouth why should not men too and other animals do so also; 10they should also, in the same way as fishes, draw in air out of the mouth. If in the former case it were possible, so also should it be in the latter. But, since in the one it is not so, neither does it occur in the other. Furthermore, why do fishes, if they respire, die in the air and gasp (as can be seen) as in suffocation? It is not want of food that produces this effect upon them, 15and the reason given by Diogenes is foolish, for he says that in air they take in too much air and hence die, but in the water they take in a moderate amount. But that should be a possible occurrence with land animals also; as facts are, however, no land animal seems to be suffocated by excessive respiration. Again, if all animals breathe, 20insects must do so also. many of them seem to live though divided not merely into two, but into several parts, e.g. the class called Scolopendra. But how can they, when thus divided, breathe, and what is the organ they employ? The main reason why these writers have not given a good account of these facts is that 25they have no acquaintance with the internal organs, and that they did not accept the doctrine that there is a final cause for whatever Nature does. If they had asked for what purpose respiration exists in animals, and had considered this with reference to the organs, e.g. the gills and the lungs, they would have discovered the reason more speedily.

Chapter 10 (471b30–472b5)

30 Δημόκριτος δ' ὅτι μὲν ἐκ τῆς ἀναπνοῆς συμβαίνει τι

τοῖς ἀναπνέουσι λέγει, φάσκων κωλύειν ἐκθλίβεσθαι τὴν

30Democritus, however, does teach that in the breathing animals there is a certain result produced by respiration; he asserts that it prevents the soul from being extruded from the body.

472a

1 ψυχήν· οὐ μέντοι ὡς τούτου γ' ἕνεκα ποιήσασαν τοῦτο τὴν

φύσιν οὐθὲν εἴρηκεν· ὅλως γὰρ ὥσπερ καὶ οἱ ἄλλοι φυσικοί,

καὶ οὗτος οὐθὲν ἅπτεται τῆς τοιαύτης αἰτίας. λέγει δ'

ὡς ἡ ψυχὴ καὶ τὸ θερμὸν ταὐτόν, τὰ πρῶτα σχήματα τῶν

5 σφαιροειδῶν. ἐκκρινομένων οὖν αὐτῶν ὑπὸ τοῦ περιέχοντος

ἐκθλίβοντος, βοήθειαν γίνεσθαι τὴν ἀναπνοήν φησιν. ἐν

γὰρ τῷ ἀέρι πολὺν ἀριθμὸν εἶναι τῶν τοιούτων ἃ καλεῖ

ἐκεῖνος νοῦν καὶ ψυχήν· ἀναπνέοντος οὖν καὶ εἰσιόντος τοῦ

ἀέρος συνεισιόντα ταῦτα καὶ ἀνείργοντα τὴν θλίψιν κωλύειν

10 τὴν ἐνοῦσαν ἐν τοῖς ζῴοις διιέναι ψυχήν, καὶ διὰ τοῦτο ἐν τῷ

ἀναπνεῖν καὶ ἐκπνεῖν εἶναι τὸ ζῆν καὶ ἀποθνήσκειν· ὅταν

γὰρ κρατῇ τὸ περιέχον συνθλῖβον, καὶ μηκέτι <τὸ> θύραθεν εἰςιὸν

δύνηται ἀνείργειν, μὴ δυναμένου ἀναπνεῖν, τότε συμβαίνειν

τὸν θάνατον τοῖς ζῴοις· εἶναι γὰρ τὸν θάνατον τὴν τῶν

15 τοιούτων σχημάτων ἐκ τοῦ σώματος ἔξοδον ἐκ τῆς τοῦ περιέχοντος

ἐκθλίψεως. τὴν δ' αἰτίαν διὰ τί ποτε πᾶσι μὲν

ἀναγκαῖον ἀποθανεῖν, οὐ μέντοι ὅτε ἔτυχεν ἀλλὰ κατὰ

φύσιν μὲν γήρᾳ, βίᾳ δὲ παρὰ φύσιν, οὐθὲν δεδήλωκεν

(καίτοι ἐχρῆν, ἐπεὶ ὁτὲ μὲν φαίνεται τοῦτο γινόμενον, ὁτὲ δ'

20 οὐ φαίνεται), πότερον τὸ αἴτιον ἔξωθέν ἐστιν ἢ ἐντός. οὐ λέγει

δὲ οὐδὲ περὶ τῆς ἀρχῆς τοῦ ἀναπνεῖν τί τὸ αἴτιον, πότερον

ἔσωθεν ἢ ἔξωθεν· οὐ γὰρ δὴ ὁ θύραθεν νοῦς τηρεῖ τὴν βοήθειαν,

ἀλλ' ἔσωθεν ἡ ἀρχὴ τῆς ἀναπνοῆς γίνεται καὶ τῆς

κινήσεως, οὐχ ὡς βιαζομένου τοῦ περιέχοντος. ἄτοπον δὲ καὶ

25 τὸ ἅμα τὸ περιέχον συνθλίβειν καὶ εἰσιὸν διαστέλλειν. ἃ

μὲν οὖν εἴρηκε καὶ ὥς, σχεδὸν ταῦτ' ἐστίν. εἰ δὲ δεῖ νομίζειν

ἀληθῆ εἶναι τὰ πρότερον λεχθέντα καὶ μὴ πάντα τὰ ζῷα

ἀναπνεῖν, οὐ περὶ παντὸς θανάτου τὴν αἰτίαν ὑποληπτέον

εἰρῆσθαι ταύτην, ἀλλὰ μόνον ἐπὶ τῶν ἀναπνεόντων. οὐ μὴν

30 οὐδ' ἐπὶ τούτων καλῶς· δῆλον δ' ἐκ τῶν συμβαινόντων καὶ

τῶν τοιούτων ὧν ἔχομεν πάντες πεῖραν. ἐν γὰρ ταῖς ἀλέαις

θερμαινόμενοι μᾶλλον καὶ τῆς ἀναπνοῆς μᾶλλον δεόμεθα

καὶ πυκνότερον ἀναπνέομεν πάντες· ὅταν δὲ τὸ πέριξ ᾖ

ψυχρὸν καὶ συνάγῃ καὶ συμπηγνύῃ τὸ σῶμα, κατέχειν

35 συμβαίνει τὸ πνεῦμα. καίτοι τότ' ἐχρῆν τὸ θύραθεν εἰσιὸν

1Nevertheless, he by no means asserts that it is for this purpose that Nature so contrives it, for he, like the other physical philosophers, altogether fails to attain to any such explanation. His statement is that the soul and the hot element are identical, being the primary forms among the spherical particles. 5Hence, when these are being crushed together by the surrounding atmosphere thrusting them out, respiration, according to his account, comes in to succour them.
For in the air there are many of those particles which he calls mind and soul. Hence, when we breathe and the air enters, these enter along with it, and by their action cancel the pressure, thus preventing the expulsion 10of the soul which resides in the animal.
This explains why life and death are bound up with the taking in and letting out of the breath; for death occurs when the compression by the surrounding air gains the upper hand, and, the animal being unable to respire, the air from outside can no longer enter and counteract the compression. Death is the departure of 15those forms owing to the expulsive pressure exerted by the surrounding air. Death, however, occurs not by haphazard but, when natural, owing to old age, and, when unnatural, to violence.
But the reason for this and why all must die Democritus has by no means made clear. And yet, since evidently death occurs at one time of life and not at another, he should have said 20whether the cause is external or internal. Neither does he assign the cause of the beginning of respiration, nor say whether it is internal or external. Indeed, it is not the case that the external mind superintends the reinforcement; rather the origin of breathing and of the respiratory motion must be within: it is not due to pressure from around. It is absurd also 25that what surrounds should compress and at the same time by entering dilate. This then is practically his theory, and how he puts it.
But if we must consider that our previous account is true, and that respiration does not occur in every animal, we must deem that this explains death not universally, but only in respiring animals. 30Yet neither is it a good account of these even, as may clearly be seen from the facts and phenomena of which we all have experience. For in hot weather we grow warmer, and, having more need of respiration, we always breathe faster.
But, when the air around is cold and contracts and solidifies the body, 35retardation of the breathing results.

472b

1 κωλύειν τὴν σύνθλιψιν. νῦν δὲ γίνεται τοὐναντίον· ὅταν

γὰρ πολὺ λίαν ἀθροισθῇ τὸ θερμὸν μὴ ἐκπνεόντων, τότε

δέονται τῆς ἀναπνοῆς· ἀναγκαῖον δ' εἰσπνεύσαντας ἀναπνεῖν.

ἀλεάζοντες δὲ πολλάκις ἀναπνέουσιν, ὡς ἀναψύξεως χάριν

5 ἀναπνέοντες ὅτε τὸ λεγόμενον ποιεῖ πῦρ ἐπὶ πῦρ.

1Yet this was just the time when the external air should enter and annul the expulsive movement, whereas it is the opposite that occurs. For when the breath is not let out and the heat accumulates too much then we need to respire, and to respire we must draw in the breath. When hot, people breathe rapidly, because they must do so in order to cool themselves, 5just when the theory of Democritus would make them add fire to fire.

Chapter 11 (472b6–473a2)

Ἡ δ' ἐν τῷ Τιμαίῳ γεγραμμένη περίωσις περί τε τῶν

ἄλλων ζῴων οὐδὲν διώρικε τίνα τρόπον αὐτοῖς ἡ τοῦ θερμοῦ

γίνεται σωτηρία, πότερον τὸν αὐτὸν ἢ δι' ἄλλην τινὰ αἰτίαν

(εἰ μὲν γὰρ μόνοις τὸ τῆς ἀναπνοῆς ὑπάρχει τοῖς πεζοῖς,

10 λεκτέον τὴν αἰτίαν τοῦ μόνοις· εἰ δὲ καὶ τοῖς ἄλλοις, ὁ δὲ

τρόπος ἄλλος, καὶ περὶ τούτου διοριστέον, εἴπερ δυνατὸν ἀναπνεῖν

πᾶσιν)· ἔτι δὲ καὶ πλασματώδης ὁ τρόπος τῆς αἰτίας.

ἐξιόντος γὰρ ἔξω τοῦ θερμοῦ διὰ τοῦ στόματος, τὸν περιέχοντα

ὠθούμενον ἀέρα φερόμενον ἐμπίπτειν εἰς τὸν αὐτὸν τόπον

15 φησὶ διὰ μανῶν οὐσῶν τῶν σαρκῶν, ὅθεν τὸ ἐντὸς ἐξῄει θερμόν,

διὰ τὸ μηδὲν εἶναι κενὸν ἀντιπεριισταμένων ἀλλήλοις·

θερμανθέντα δὲ πάλιν ἐξιέναι κατὰ τὸν αὐτὸν τόπον, καὶ

περιωθεῖν εἴσω διὰ τοῦ στόματος τὸν ἀέρα τὸν ἐκπίπτοντα

θερμόν· καὶ τοῦτο δὴ διατελεῖν ἀεὶ ποιοῦντας, ἀναπνέοντάς τε

20 καὶ ἐκπνέοντας. συμβαίνει δὲ τοῖς οὕτως οἰομένοις πρότερον

τὴν ἐκπνοὴν γίνεσθαι τῆς εἰσπνοῆς. ἔστι δὲ τοὐναντίον· σημεῖον

δέ· γίνεται μὲν γὰρ ἀλλήλοις ταῦτα παρ' ἄλληλα, τελευτῶντες

δὲ ἐκπνέουσιν, ὥστ' ἀναγκαῖον εἶναι τὴν ἀρχὴν

εἰσπνοήν. ἔτι δὲ τὸ τίνος ἕνεκα ταῦθ' ὑπάρχει τοῖς ζῴοις

25 (λέγω δὲ τὸ ἀναπνεῖν καὶ τὸ ἐκπνεῖν) οὐθὲν εἰρήκασιν οἱ τοῦτον

τὸν τρόπον λέγοντες, ἀλλ' ὡς περὶ συμπτώματός τινος

ἀποφαίνονται μόνον. καίτοι γε κύρια ταῦθ' ὁρῶμεν τοῦ ζῆν

καὶ τελευτᾶν· ὅταν γὰρ ἀναπνεῖν μὴ δύνωνται, τότε συμβαίνει

γίνεσθαι τὴν φθορὰν τοῖς ἀναπνέουσιν. ἔτι δὲ ἄτοπον

30 τὸ τὴν μὲν τοῦ θερμοῦ διὰ τοῦ στόματος ἔξοδον καὶ πάλιν

εἴσοδον μὴ λανθάνειν ἡμᾶς, τὴν δ' εἰς τὸν θώρακα τοῦ πνεύματος

εἴσοδον καὶ πάλιν θερμανθέντος ἔξοδον λανθάνειν.

ἄτοπον δὲ καὶ τοῦ θερμοῦ τὴν ἀναπνοὴν εἴσοδον εἶναι. φαίνεται

γὰρ τοὐναντίον· τὸ μὲν γὰρ ἐκπνεόμενον εἶναι θερμόν,

35 τὸ δ' εἰσπνεόμενον ψυχρόν. ὅταν δὲ θερμὸν ᾖ, ἀσθμαίνοντες

6The theory found in the Timaeus, of the passing round of the breath by pushing, by no means determines how, in the case of the animals other than land-animals, their heat is preserved, and whether it is due to the same or a different cause. For if respiration occurs only in land-animals 10we should be told what is the reason of that. Likewise, if it is found in others also, but in a different form, this form of respiration, if they all can breathe, must also be described.
Further, the method of explaining involves a fiction. It is said that when the hot air issues from the mouth it pushes the surrounding air, which being carried on enters the very place 15whence the internal warmth issued, through the interstices of the porous flesh; and this reciprocal replacement is due to the fact that a vacuum cannot exist. But when it has become hot the air passes out again by the same route, and pushes back inwards through the mouth the air that had been discharged in a warm condition.
It is said that it is this action which goes on continuously when the breath is taken in and let out.
20But according to this way of thinking it will follow that we breathe out before we breathe in. But the opposite is the case, as evidence shows, for though these two functions go on in alternation, yet the last act when life comes to a close is the letting out of the breath, and hence its admission must have been the beginning of the process.
Once more, those who give this kind of explanation by no means state the final cause of the presence in animals of this function 25(to wit the admission and emission of the breath), but treat it as though it were a contingent accompaniment of life. Yet it evidently has control over life and death, for it results synchronously that when respiring animals are unable to breathe they perish. Again, it is absurd 30that the passage of the hot air out through the mouth and back again should be quite perceptible, while we were not able to detect the thoracic influx and the return outwards once more of the heated breath. It is also nonsense that respiration should consist in the entrance of heat, for the evidence is to the contrary effect; what is breathed out is hot, and 35what is breathed in is cold.

473a

1 ἀναπνέουσιν· διὰ γὰρ τὸ μὴ καταψύχειν ἱκανῶς τὸ εἰσιὸν

πολλάκις τὸ πνεῦμα συμβαίνει σπᾶν.

1When it is hot we pant in breathing, for, because what enters does not adequately perform its cooling function, we have as a consequence to draw the breath frequently.

Chapter 12 (473a3–14)

Ἀλλὰ μὴν οὐδὲ τροφῆς γε χάριν ὑποληπτέον γίνεσθαι

τὴν ἀναπνοήν, ὡς τρεφομένου τῷ πνεύματι τοῦ ἐντὸς πυρός,

5 καὶ ἀναπνέοντος μὲν ὥσπερ ἐπὶ πῦρ ὑπέκκαυμα ὑποβάλλεσθαι,

τραφέντος δὲ τοῦ πυρὸς γίγνεσθαι τὴν ἐκπνοήν. ταὐτὰ

γὰρ ἐροῦμεν πάλιν καὶ πρὸς τοῦτον τὸν λόγον ἅπερ καὶ πρὸς

τοὺς ἔμπροσθεν· καὶ γὰρ ἐπὶ τῶν ἄλλων ζῴων ἐχρῆν τοῦτο

συμβαίνειν ἢ τὸ ἀνάλογον τούτῳ· πάντα γὰρ ἔχει θερμότητα

10 ζωτικήν. ἔπειτα καὶ τὸ γίγνεσθαι τὸ θερμὸν ἐκ τοῦ πνεύματος

τίνα χρὴ τρόπον λέγειν, πλασματῶδες ὄν; μᾶλλον

γὰρ ἐκ τῆς τροφῆς τοῦτο γιγνόμενον ὁρῶμεν. συμβαίνει τε

κατὰ ταὐτὸ δέχεσθαι τὴν τροφὴν καὶ τὸ περίττωμα ἀφιέναι·

τοῦτο δ' ἐπὶ τῶν ἄλλων οὐχ ὁρῶμεν γινόμενον.

3It is certain, however, that we must not entertain the notion that it is for purposes of nutrition that respiration is designed, and believe that the internal fire is fed by the breath; 5respiration, as it were, adding fuel to the fire, while the feeding of the flame results in the outward passage of the breath. To combat this doctrine I shall repeat what I said in opposition to the previous theories. This, or something analogous to it, should occur in the other animals also (on this theory), for all possess vital heat. 10Further, how are we to describe this fictitious process of the generation of heat from the breath? Observation shows rather that it is a product of the food. A consequence also of this theory is that the nutriment would enter and the refuse be discharged by the same channel, but this does not appear to occur in the other instances.

Chapter 13 (473a15–474a24)

15 Λέγει δὲ περὶ ἀναπνοῆς καὶ Ἐμπεδοκλῆς, οὐ μέντοι

τίνος γ' ἕνεκα, οὐδὲ περὶ πάντων τῶν ζῴων οὐδὲν ποιεῖ δῆλον,

εἴτε ἀναπνέουσιν εἴτε μή. καὶ περὶ τῆς διὰ τῶν μυκτήρων

ἀναπνοῆς λέγων οἴεται καὶ περὶ τῆς κυρίας λέγειν ἀναπνοῆς.

ἔστι γὰρ καὶ διὰ τῆς ἀρτηρίας ἐκ τῶν στηθῶν ἀναπνοὴ

20 καὶ ἡ διὰ τῶν μυκτήρων· αὐτοῖς δὲ χωρὶς ἐκείνης οὐκ

ἔστιν ἀναπνεῦσαι τοῖς μυκτῆρσιν. καὶ τῆς μὲν διὰ τῶν μυκτήρων

γινομένης ἀναπνοῆς στερισκόμενα τὰ ζῷα οὐδὲν πάσχουσι,

τῆς δὲ κατὰ τὴν ἀρτηρίαν ἀποθνήσκουσιν. καταχρῆται

γὰρ ἡ φύσις ἐν παρέργῳ τῇ διὰ τῶν μυκτήρων

25 ἀναπνοῇ πρὸς τὴν ὄσφρησιν ἐν ἐνίοις τῶν ζῴων· διόπερ

ὀσφρήσεως μὲν σχεδὸν μετέχει πάντα τὰ ζῷα, ἔστι δ' οὐ

πᾶσι τὸ αὐτὸ αἰσθητήριον. εἴρηται δὲ περὶ αὐτῶν ἐν ἑτέροις

15Empedocles also gives an account of respiration without, however, making clear what its purpose is, or whether or not it is universal in animals. Also when dealing with respiration by means of the nostrils he imagines he is dealing with what is the primary kind of respiration. Even the breath which passes through the nostrils passes through the windpipe out of the chest as well, 20and without the latter the nostrils cannot act.
Again, when animals are bereft of respiration through the nostrils, no detrimental result ensues, but, when prevented from breathing through the windpipe, they die. Nature employs respiration through the nostrils as a secondary function in certain animals in order to enable them to smell.
25But the reason why it exists in some only is that though almost all animals are endowed with the sense of smell, the sense-organ is not the same in all.

473b

1 σαφέστερον. γίγνεσθαι δέ φησι τὴν ἀναπνοὴν καὶ ἐκπνοὴν διὰ

τὸ φλέβας εἶναί τινας ἐν αἷς ἔνεστι μὲν αἷμα, οὐ μέντοι

πλήρεις εἰσὶν αἵματος, ἔχουσι δὲ πόρους εἰς τὸν ἔξω ἀέρα,

τῶν μὲν τοῦ σώματος μορίων ἐλάττους, τῶν δὲ τοῦ ἀέρος

5 μείζους· διὸ τοῦ αἵματος πεφυκότος κινεῖσθαι ἄνω καὶ

κάτω, κάτω μὲν φερομένου εἰσρεῖν τὸν ἀέρα καὶ γίγνεσθαι

ἀναπνοήν, ἄνω δ' ἰόντος ἐκπίπτειν θύραζε καὶ γίνεσθαι τὴν

ἐκπνοήν, παρεικάζων τὸ συμβαῖνον ταῖς κλεψύδραις.

ὧδε δ' ἀναπνεῖ πάντα καὶ ἐκπνεῖ· πᾶσι λίφαιμοι

10 σαρκῶν σύριγγες πύματον κατὰ σῶμα τέτανται,

καί σφιν ἐπὶ στομίοις πυκιναῖς τέτρηνται ἄλοξιν

ῥινῶν ἔσχατα τέρθρα διαμπερές, ὥστε φόνον μέν

κεύθειν, αἰθέρι δ' εὐπορίην διόδοισι τετμῆσθαι.

ἔνθεν ἔπειθ' ὁπόταν μὲν ἀπαΐξῃ τέρεν αἷμα,

15 αἰθὴρ παφλάζων καταΐσσεται οἴδματι μάργῳ,

εὖτε δ' ἀναθρῴσκῃ, πάλιν ἐκπνέει, ὥσπερ ὅταν παῖς

κλεψύδρῃ παίζῃσι διειπετέος χαλκοῖο—

εὖτε μὲν αὐλοῦ πορθμὸν ἐπ' εὐειδεῖ χερὶ θεῖσα

εἰς ὕδατος βάπτῃσι τέρεν δέμας ἀργυφέοιο,

20 οὐδεὶς ἄγγοσδ' ὄμβρος ἐσέρχεται, ἀλλά μιν εἴργει

ἀέρος ὄγκος ἔσωθε πεσὼν ἐπὶ τρήματα πυκνά,

εἰσόκ' ἀποστεγάσῃ πυκινὸν ῥόον· αὐτὰρ ἔπειτα

πνεύματος ἐλλείποντος ἐσέρχεται αἴσιμον ὕδωρ.

ὡς δ' αὔτως, ὅθ' ὕδωρ μὲν ἔχῃ κάτα βένθεα χαλκοῦ

25 πορθμοῦ χωσθέντος βροτέῳ χροῒ ἠδὲ πόροιο,

αἰθὴρ δ' ἐκτὸς ἔσω λελιημένος ὄμβρον ἐρύκῃ

ἀμφὶ πύλας ἠθμοῖο δυσηχέος ἄκρα κρατύνων,

1A more precise account has been given about this elsewhere. Empedocles, however, explains the passage inwards and outwards of the breath, by the theory that there are certain blood-vessels, which, while containing blood, are not filled by it, but have passages leading to the outer air, the calibre of which is fine in contrast to the size of the solid particles, but large relatively to those in the air. 5Hence, since it is the nature of the blood to move upwards and downwards, when it moves down the air rushes in and inspiration occurs; when the blood rises, the air is forced out and the outward motion of the breath results. He compares this process to what occurs in a clepsydra.
Thus all things outwards breathe and in;- 10their flesh has tubes Bloodless, that stretch towards the body's outmost edge, Which, at their mouths, full many frequent channels pierce, Cleaving the extreme nostrils through; thus, while the gore Lies hid, for air is cut a thoroughfare most plain.
And thence, whenever shrinks away the tender blood, 15Enters the blustering wind with swelling billow wild.
But when the blood leaps up, backward it breathes. As when With water-clock of polished bronze a maiden sporting, Sets on her comely hand the narrow of the tube And dips it in the frail-formed water's silvery sheen; 20Not then the flood the vessel enters, but the air, Until she frees the crowded stream. But then indeed Upon the escape runs in the water meet.
So also when within the vessel's deeps the water Remains, 25the opening by the hand of flesh being closed, The outer air that entrance craves restrains the flood At the gates of the sounding narrow, upon the surface pressing, Until the maid withdraws her hand.

474a

1 εἰσόκε χειρὶ μεθῇ, τότε δ' αὖ πάλιν, ἔμπαλιν ἢ πρίν,

πνεύματος ἐμπίπτοντος ὑπεκθέει αἴσιμον ὕδωρ.

ὡς δ' αὔτως τέρεν αἷμα κλαδασσόμενον διὰ γυίων

ὁππότε μὲν παλίνορσον ἀπαΐξειε μυχόνδε,

5 αἰθέρος εὐθὺς ῥεῦμα κατέρχεται οἴδματι θῦον,

εὖτε δ' ἀναθρῴσκῃ, πάλιν ἐκπνέει ἶσον ὀπίσσω.

λέγει μὲν οὖν ταῦτα περὶ τοῦ ἀναπνεῖν. ἀναπνεῖ δ', ὥσπερ

εἴπομεν, τὰ φανερῶς ἀναπνέοντα διὰ τῆς ἀρτηρίας, διά τε

τοῦ στόματος ἅμα καὶ διὰ τῶν μυκτήρων. ὥστ' εἰ μὲν περὶ

10 ταύτης λέγει τῆς ἀναπνοῆς, ἀναγκαῖον ζητεῖν πῶς ἐφαρμόσει

ὁ εἰρημένος λόγος τῆς αἰτίας· φαίνεται γὰρ τοὐναντίον συμβαῖνον.

ἄραντες μὲν γὰρ τὸν τόπον, καθάπερ τὰς φύσας

ἐν τοῖς χαλκείοις, ἀναπνέουσιν (αἴρειν δὲ τὸ θερμὸν εὔλογον,

ἔχειν δὲ τὸ αἷμα τὴν τοῦ θερμοῦ χώραν)· συνιζάνοντες

15 δὲ καὶ καταπλήττοντες, ὥσπερ ἐκεῖ τὰς φύσας, ἐκπνέουσιν.

πλὴν ἐκεῖ μὲν οὐ κατὰ ταὐτὸν εἰσδέχονταί τε τὸν ἀέρα καὶ

πάλιν ἐξιᾶσιν, οἱ δ' ἀναπνέοντες κατὰ ταὐτόν. εἰ δὲ περὶ

τῆς κατὰ τοὺς μυκτῆρας λέγει μόνης, πολὺ διημάρτηκεν·

οὐ γάρ ἐστιν ἀναπνοὴ μυκτήρων ἴδιος, ἀλλὰ παρὰ τὸν

20 αὐλῶνα τὸν παρὰ τὸν γαργαρεῶνα, ᾗ τὸ ἔσχατον τοῦ ἐν τῷ

στόματι οὐρανοῦ, συντετρημένων τῶν μυκτήρων χωρεῖ τὸ μὲν

ταύτῃ τοῦ πνεύματος, τὸ δὲ διὰ τοῦ στόματος, ὁμοίως εἰσιόν

τε καὶ ἐξιόν. τὰ μὲν οὖν παρὰ τῶν ἄλλων εἰρημένα περὶ τοῦ

ἀναπνεῖν τοιαύτας καὶ τοσαύτας ἔχει δυσχερείας.

1But then in contrariwise Once more the air comes in and water meet flows out.
Thus to the to the subtle blood, surging throughout the limbs, Whene'er it shrinks away into the far recesses 5Admits a stream of air rushing with swelling wave, But, when it backward leaps, in like bulk air flows out.
This then is what he says of respiration. But, as we said, all animals that evidently respire do so by means of the windpipe, when they breathe either through the mouth or through the nostrils. Hence, 10if it is of this kind of respiration that he is talking, we must ask how it tallies with the explanation given. But the facts seem to be quite opposed. The chest is raised in the manner of a forge-bellows when the breath is drawn in-it is quite reasonable that it should be heat which raises up and that the blood should occupy the hot region-but it collapses 15and sinks down, like the bellows once more, when the breath is let out. The difference is that in a bellows it is not by the same channel that the air is taken in and let out, but in breathing it is.
But, if Empedocles is accounting only for respiration through the nostrils, he is much in error, for that does not involve the nostrils alone, but passes by 20the channel beside the uvula where the extremity of the roof of the mouth is, some of the air going this way through the apertures of the nostrils and some through the mouth, both when it enters and when it passes out. Such then is the nature and magnitude of the difficulties besetting the theories of other writers concerning respiration.
Section 2

Chapter 14 (474a25–474b24)

25 Ἐπεὶ δὲ εἴρηται πρότερον ὅτι τὸ ζῆν καὶ ἡ τῆς ψυχῆς

ἕξις μετὰ θερμότητός τινός ἐστιν (οὐδὲ γὰρ ἡ πέψις,

δι' ἧς ἡ τροφὴ γίνεται τοῖς ζῴοις, οὔτ' ἄνευ ψυχῆς οὔτ' ἄνευ

θερμότητός ἐστιν· πυρὶ γὰρ ἐργάζεται πάντα), διόπερ ἐν ᾧ

πρώτῳ τόπῳ τοῦ σώματος καὶ ἐν ᾧ πρώτῳ τοῦ τόπου τούτου

30 μορίῳ τὴν ἀρχὴν ἀναγκαῖον εἶναι τὴν τοιαύτην, ἐνταῦθα

καὶ τὴν πρώτην θρεπτικὴν ψυχὴν ἀναγκαῖον ὑπάρχειν,

25We have already stated that life and the presence of soul involve a certain heat. Not even the digesting process to which is due the nutrition of animals occurs apart from soul and warmth, for it is to fire that in all cases elaboration is due. It is for this reason, precisely, that the primary nutritive soul also must be located in 30that part of the body and in that division of this region which is the immediate vehicle of this principle.

474b

1 οὗτος δ' ἐστὶν ὁ μέσος τόπος τοῦ δεχομένου τὴν τροφὴν καὶ

καθ' ὃν ἀφίησι τὸ περίττωμα, τοῖς μὲν οὖν ἀναίμοις ἀνώνυμον,

τοῖς δ' ἐναίμοις ἡ καρδία τοῦτο τὸ μόριόν ἐστιν. ἡ τροφὴ

μὲν γὰρ ἐξ ἧς ἤδη γίνεται τὰ μόρια τοῖς ζῴοις ἡ τοῦ αἵματος

5 φύσις ἐστίν. τοῦ δ' αἵματος καὶ τῶν φλεβῶν τὴν αὐτὴν

ἀρχὴν ἀναγκαῖον εἶναι· θατέρου γὰρ ἕνεκα θάτερόν ἐστιν, ὡς

ἀγγεῖον καὶ δεκτικόν. ἀρχὴ δὲ τῶν φλεβῶν ἡ καρδία τοῖς

ἐναίμοις· οὐ γὰρ διὰ ταύτης, ἀλλ' ἐκ ταύτης ἠρτημέναι

πᾶσαι τυγχάνουσιν· δῆλον δ' ἡμῖν τοῦτο ἐκ τῶν ἀνατομῶν.

10 τὰς μὲν οὖν ἄλλας δυνάμεις τῆς ψυχῆς ἀδύνατον ὑπάρχειν

ἄνευ τῆς θρεπτικῆς (δι' ἣν δ' αἰτίαν, εἴρηται πρότερον ἐν

τοῖς Περὶ ψυχῆς), ταύτην δ' ἄνευ τοῦ φυσικοῦ πυρός· ἐν

τούτῳ γὰρ ἡ φύσις ἐμπεπύρευκεν αὐτήν. φθορὰ δὲ πυρός,

ὥσπερ εἴρηται πρότερον, σβέσις καὶ μάρανσις, σβέσις μὲν

15 ἡ ὑπὸ τῶν ἐναντίων (διόπερ ἀθρόον τε ὑπὸ τῆς τοῦ περιέχοντος

ψυχρότητος καὶ θᾶττον σβέννυται διασπώμενον·

αὕτη μὲν οὖν ἡ φθορὰ βίαιος ὁμοίως ἐπὶ τῶν ἐμψύχων καὶ

τῶν ἀψύχων ἐστίν· καὶ γὰρ ὀργάνοις διαιρουμένου τοῦ ζῴου,

καὶ πηγνυμένου διὰ ψύχους ὑπερβολήν, ἀποθνήσκουσιν), ἡ

20 δὲ μάρανσις διὰ πλῆθος θερμότητος· καὶ γὰρ ἂν ὑπερβάλλῃ

τὸ πέριξ θερμόν, καὶ τροφὴν ἐὰν μὴ λαμβάνῃ,

φθείρεται τὸ πυρούμενον, οὐ ψυχόμενον ἀλλὰ μαραινόμενον.

ὥστ' ἀνάγκη γίγνεσθαι κατάψυξιν, εἰ μέλλει τεύξεσθαι σωτηρίας·

τοῦτο γὰρ βοηθεῖ πρὸς ταύτην τὴν φθοράν.

1The region in question is intermediate between that where food enters and that where excrement is discharged. In bloodless animals it has no name, but in the sanguineous class this organ is called the heart. The blood constitutes the nutriment from which the organs of the animal are directly formed. 5Likewise the bloodvessels must have the same originating source, since the one exists for the other's behoof-as a vessel or receptacle for it. In sanguineous animals the heart is the starting-point of the veins; they do not traverse it, but are found to stretch out from it, as dissections enable us to see.
10Now the other psychical faculties cannot exist apart from the power of nutrition (the reason has already been stated in the treatise On the Soul), and this depends on the natural fire, by the union with which Nature has set it aglow. But fire, as we have already stated, is destroyed in two ways, either by extinction or by exhaustion. It suffers extinction from its opposites. 15Hence it can be extinguished by the surrounding cold both when in mass and (though more speedily) when scattered. Now this way of perishing is due to violence equally in living and in lifeless objects, for the division of an animal by instruments and consequent congelation by excess of cold cause death. 20But exhaustion is due to excess of heat; if there is too much heat close at hand and the thing burning does not have a fresh supply of fuel added to it, it goes out by exhaustion, not by the action of cold. Hence, if it is going to continue it must be cooled, for cold is a preventive against this form of extinction.

Chapter 15 (474b25–475b14)

25 Ἐπεὶ δὲ τῶν ζῴων τὰ μὲν ἔνυδρα, τὰ δ' ἐν τῇ γῇ

ποιεῖται τὴν διατριβήν, τούτων τοῖς μὲν μικροῖς πάμπαν καὶ

τοῖς ἀναίμοις ἡ γινομένη ἐκ τοῦ περιέχοντος ἢ ὕδατος ἢ

ἀέρος ψύξις ἱκανὴ πρὸς τὴν βοήθειαν τῆς φθορᾶς ταύτης·

μικρὸν γὰρ ἔχοντα τὸ θερμὸν μικρᾶς δέονται τῆς βοηθείας.

30 διὸ καὶ βραχύβια σχεδὸν πάντα τὰ τοιαῦτ' ἐστίν· ἐπ' ἀμφότερα

γὰρ μικρὰ ὄντα μικρᾶς τυγχάνει ῥοπῆς. ὅσα δὲ μακροβιώτερα

25Some animals occupy the water, others live on land, and, that being so, in the case of those which are very small and bloodless the refrigeration due to the surrounding water or air is sufficient to prevent destruction from this cause. Having little heat, they require little cold to combat it. 30Hence too such animals are almost all short-lived, for, being small, they have less scope for deflection towards either extreme.

475a

1 τῶν ἐντόμων (ἄναιμα γάρ ἐστι πάντα τὰ ἔντομα),

τούτοις ὑπὸ τὸ διάζωμα διέσχισται, ὅπως διὰ λεπτοτέρου ὄντος

τοῦ ὑμένος ψύχηται· μᾶλλον γὰρ ὄντα θερμὰ πλείονος

δεῖται τῆς καταψύξεως, οἷον αἱ μέλιτται (τῶν γὰρ μελιττῶν

5 ἔνιαι ζῶσι καὶ ἑπτὰ ἔτη) καὶ τἆλλα δὲ ὅσα βομβεῖ,

οἷον σφῆκες καὶ μηλολόνθαι καὶ τέττιγες. καὶ γὰρ τὸν

ψόφον ποιοῦσι πνεύματι, οἷον ἀσθμαίνοντα· ἐν αὐτῷ γὰρ

τῷ ὑποζώματι, τῷ ἐμφύτῳ πνεύματι αἰρομένῳ καὶ συνίζοντι,

συμβαίνει πρὸς τὸν ὑμένα γίνεσθαι τρίψιν· κινοῦσι

10 γὰρ τὸν τόπον τοῦτον, ὥσπερ τὰ ἀναπνέοντα ἔξωθεν τῷ

πνεύμονι καὶ οἱ ἰχθύες τοῖς βραγχίοις. παραπλήσιον γὰρ

συμβαίνει κἂν εἴ τίς τινα τῶν ἀναπνεόντων πνίγοι, τὸ

στόμα κατασχών· καὶ γὰρ ταῦτα ποιήσει τῷ πνεύμονι τὴν

ἄρσιν ταύτην· ἀλλὰ τούτοις μὲν οὐχ ἱκανὴν ἡ τοιαύτη ποιεῖ

15 κίνησις κατάψυξιν, ἐκείνοις δ' ἱκανήν. καὶ τῇ τρίψει τῇ

πρὸς τὸν ὑμένα ποιοῦσι τὸν βόμβον, ὥσπερ λέγομεν, οἷον

διὰ τῶν καλάμων τῶν τετρυπημένων τὰ παιδία, ὅταν ἐπιθῶσιν

ὑμένα λεπτόν. διὰ γὰρ τοῦτο καὶ τῶν τεττίγων οἱ

ᾄδοντες ᾄδουσιν· θερμότεροι γάρ εἰσι, καὶ ἔσχισται αὐτοῖς

20 ὑπὸ τὸ ὑπόζωμα· τοῖς δὲ μὴ ᾄδουσι τοῦτ' ἐστὶν ἄσχιστον. καὶ

τῶν ἀναίμων δὲ καὶ πνεύμονα ἐχόντων, ὀλίγαιμον δ' ἐχόντων

καὶ σομφόν, ἔνια διὰ τοῦτο πολὺν χρόνον δύνανται

ἀπνευστὶ ζῆν, ὅτι ὁ πνεύμων ἄρσιν ἔχει πολλήν, ὀλίγον

ἔχων τὸ αἷμα καὶ τὸ ὑγρόν· ἡ γὰρ οἰκεία κίνησις ἐπὶ πολὺν

25 χρόνον διαρκεῖ καταψύχουσα. τέλος δ' οὐ δύναται,

ἀλλ' ἀποπνίγεται μὴ ἀναπνεύσαντα, καθάπερ εἴρηται καὶ

πρότερον· τῆς γὰρ μαράνσεως ἡ διὰ τὸ μὴ ψύχεσθαι

φθορὰ καλεῖται πνίξις, καὶ τὰ οὕτω φθειρόμενα ἀποπνίγεσθαί

φαμεν. ὅτι δ' οὐκ ἀναπνεῖ τὰ ἔντομα τῶν ζῴων, εἴρηται

30 μὲν καὶ πρότερον, φανερὸν δὲ καὶ ἐπὶ τῶν μικρῶν ἐστι

ζῴων, οἷον μυιῶν καὶ μελιττῶν· ἐν γὰρ τοῖς ὑγροῖς πολὺν

1But some insects are longer-lived though bloodless, like all the others), and these have a deep indentation beneath the waist, in order to secure cooling through the membrane, which there is thinner. They are warmer animals and hence require more refrigeration, and such are bees (some of which 5live as long as seven years) and all that make a humming noise, like wasps, cockchafers, and crickets. They make a sound as if of panting by means of air, for, in the middle section itself, the air which exists internally and is involved in their construction, causing a rising and falling movement, produces friction against the membrane. 10The way in which they move this region is like the motion due to the lungs in animals that breathe the outer air, or to the gills in fishes. What occurs is comparable to the suffocation of a respiring animal by holding its mouth, for then the lung causes a heaving motion of this kind. 15In the case of these animals this internal motion is not sufficient for refrigeration, but in insects it is. It is by friction against the membrane that they produce the humming sound, as we said, in the way that children do by blowing through the holes of a reed covered by a fine membrane. It is thus that the singing crickets too produce their song; they possess greater warmth and are 20indented at the waist, but the songless variety have no fissure there.
Animals also which are sanguineous and possess a lung, though that contains little blood and is spongy, can in some cases, owing to the latter fact, live a long time without breathing; for the lung, containing little blood or fluid, can rise a long way: its own motion can for a long time produce sufficient refrigeration. 25But at last it ceases to suffice, and the animal dies of suffocation if it does not respire-as we have already said. For of exhaustion that kind which is destruction due to lack of refrigeration is called suffocation, and whatsoever is thus destroyed is said to be suffocated.
30We have already stated that among animals insects do not respire, and the fact is open to observation in the case of even small creatures like flies and bees, for they can swim about in a fluid for a long time if it is not too hot or too cold.

475b

1 χρόνον ἀνανήχεται, ἂν μὴ λίαν ᾖ θερμὸν ἢ ψυχρόν· καίτοι

τὰ μικρὰν ἔχοντα δύναμιν πυκνότερον ζητεῖ ἀναπνεῖν. ἀλλὰ

φθείρεται ταῦτα καὶ λέγεται ἀποπνίγεσθαι πληρουμένης τῆς

κοιλίας καὶ φθειρομένου τοῦ ἐν τῷ ὑποζώματι θερμοῦ· διὸ καὶ

5 ἐν τῇ τέφρᾳ χρονισθέντα ἀνίσταται. καὶ τῶν ἐν τῷ ὑγρῷ δὲ

ζώντων ὅσα ἄναιμα πλείω χρόνον ζῇ ἐν τῷ ἀέρι τῶν ἐναίμων

καὶ δεχομένων τὴν θάλατταν, οἷον τῶν ἰχθύων· διὰ

γὰρ τὸ ὀλίγον ἔχειν τὸ θερμὸν ὁ ἀὴρ ἱκανός ἐστιν ἐπὶ πολὺν

χρόνον καταψύχειν, οἷον τοῖς τε μαλακοστράκοις καὶ τοῖς

10 πολύποσιν (οὐ μὴν εἰς τέλος γε διαρκεῖ πρὸς τὸ ζῆν [διὰ] τὸ

ὀλιγόθερμα εἶναι)· ἐπεὶ καὶ τῶν ἰχθύων [οἱ] πολλοὶ ζῶσιν ἐν

τῇ γῇ, ἀκινητίζοντες μέντοι, καὶ εὑρίσκονται ὀρυττόμενοι.

ὅσα γὰρ ἢ μηδ' ὅλως ἔχει πνεύμονα ἢ ἄναιμον, ἐλαττονάκις

δεῖται καταψύξεως.

1Yet animals with little strength tend to breathe more frequently. These, however, die of what is called suffocation when the stomach becomes filled and the heat in the central segment is destroyed. This explains also why 5they revive after being among ashes for a time.
Again among water-animals those that are bloodless remain alive longer in air than those that have blood and admit the sea-water, as, for example, fishes. Since it is a small quantity of heat they possess, the air is for a long time adequate for the purposes of refrigeration in such animals as the crustacea and the polyps. 10It does not however suffice, owing to their want of heat, to keep them finally in life, for most fishes also live though among earth, yet in a motionless state, and are to be found by digging. For all animals that have no lung at all or have a bloodless one require less refrigeration.

Chapter 16 (475b15–476a15)

15 Περὶ μὲν οὖν τῶν ἀναίμων, ὅτι τοῖς μὲν ὁ περιέχων

ἀὴρ τοῖς δὲ τὸ ὑγρὸν βοηθεῖ πρὸς τὴν ζωήν, εἴρηται· τοῖς

δ' ἐναίμοις καὶ τοῖς ἔχουσι καρδίαν, ὅσα μὲν ἔχει πνεύμονα

πάντα δέχεται τὸν ἀέρα καὶ τὴν κατάψυξιν ποιεῖται

διὰ τοῦ ἀναπνεῖν καὶ ἐκπνεῖν. ἔχει δὲ πνεύμονα τά τε

20 ζῳοτοκοῦντα ἐν αὑτοῖς καὶ μὴ θύραζε μόνον (τὰ γὰρ σελάχη

ζῳοτοκεῖ μέν, ἀλλ' οὐκ ἐν αὑτοῖς) καὶ τῶν ᾠοτοκούντων

τά τε πτερυγωτά, οἷον ὄρνιθες, καὶ τὰ φολιδωτά, οἷον

χελῶναι καὶ σαῦραι καὶ ὄφεις. ἐκεῖνα μὲν οὖν ἔναιμον,

τούτων δὲ τὰ πλεῖστα τὸν πνεύμονα ἔχει σομφόν· διὸ καὶ

25 τῇ ἀναπνοῇ χρῆται μανότερον, ὥσπερ εἴρηται καὶ πρότερον.

χρῆται δὲ πάντα, καὶ ὅσα διατρίβει καὶ ποιεῖται τὸν

βίον ἐν τοῖς ὕδασιν, οἷον τὸ τῶν ὕδρων γένος καὶ βατράχων

καὶ κροκοδείλων καὶ ἑμύδων καὶ χελῶναι αἵ τε θαλάττιαι

καὶ αἱ χερσαῖαι καὶ φῶκαι· ταῦτα γὰρ πάντα καὶ

30 τὰ τοιαῦτα καὶ τίκτει ἐν τῷ ξηρῷ καὶ καθεύδει ἢ ἐν

τῷ ξηρῷ, ἢ ἐν τῷ ὑγρῷ ὑπερέχοντα τὸ στόμα διὰ τὴν ἀναπνοήν.

15Concerning the bloodless animals we have declared that in some cases it is the surrounding air, in others fluid, that aids the maintenance of life. But in the case of animals possessing blood and heart, all which have a lung admit the air and produce the cooling effect by breathing in and out. All animals have a lung 20that are viviparous and are so internally, not externally merely (the Selachia are viviparous, but not internally), and of the oviparous class those that have wings, e.g. birds, and those with scales, e.g. tortoises, lizards, and snakes. The former class have a lung charged with blood, but in the most part of the latter it is spongy.
25Hence they employ respiration more sparingly as already said. The function is found also in all that frequent and pass their life in the water, e.g.
the class of water-snakes and frogs and crocodiles and hemydes, both sea- and land-tortoises, and seals.
All these 30and similar animals both bring forth on land and sleep on shore or, when they do so in the water, keep the head above the surface in order to respire.

476a

1 ὅσα δὲ βράγχια ἔχει πάντα καταψύχεται δεχόμενα

τὸ ὕδωρ· ἔχει δὲ βράγχια τὸ τῶν καλουμένων σελαχῶν

γένος καὶ τῶν ἄλλων ἀπόδων. ἄποδες δ' οἱ ἰχθύες

πάντες· καὶ γὰρ ἃ ἔχει, καθ' ὁμοιότητα τῶν πτερύγων

5 λέγεται. τῶν δὲ πόδας ἐχόντων ἓν ἔχει βράγχια μόνον τῶν

τεθεωρημένων, ὁ καλούμενος κορδύλος. ἅμα δὲ πνεύμονα

καὶ βράγχια οὐδὲν ὦπταί πω ἔχον. αἴτιον δ' ὅτι ὁ μὲν

πνεύμων τῆς ὑπὸ τοῦ πνεύματος καταψύξεως ἕνεκέν ἐστιν

(ἔοικε δὲ καὶ τοὔνομα εἰληφέναι ὁ πνεύμων διὰ τὴν τοῦ

10 πνεύματος ὑποδοχήν), τὰ δὲ βράγχια πρὸς τὴν ἀπὸ τοῦ

ὕδατος κατάψυξιν. ἓν δ' ἐφ' ἓν χρήσιμον ὄργανον, καὶ

μία κατάψυξις ἱκανὴ πᾶσιν, ὥστ' ἐπεὶ μάτην οὐδὲν ὁρῶμεν

ποιοῦσαν τὴν φύσιν, δυοῖν δ' ὄντοιν θάτερον ἂν ἦν μάτην,

διὰ τοῦτο τὰ μὲν ἔχει βράγχια τὰ δὲ πνεύμονα, ἄμφω

15 δ' οὐδέν.

1But all with gills produce refrigeration by taking in water; the Selachia and all other footless animals have gills. Fish are footless, and the limbs they have get their name (pterugion) from their similarity to wings (pterux). 5But of those with feet one only, so far as observed, has gills. It is called the tadpole.
No animal yet has been seen to possess both lungs and gills, and the reason for this is that the lung is designed for the purpose of refrigeration by means of the air (it seems to have derived its name (pneumon) from its function as a receptacle of the breath (pneuma)), 10while gills are relevant to refrigeration by water. Now for one purpose one organ is adapted and one single means of refrigeration is sufficient in every case. Hence, since we see that Nature does nothing in vain, and if there were two organs one would be purposeless, this is the reason why some animals have gills, others lungs, 15but none possess both.

Chapter 17 (476a16–476b12)

Ἐπεὶ δὲ πρὸς μὲν τὸ εἶναι τροφῆς δεῖται τῶν ζῴων

ἕκαστον, πρὸς δὲ τὴν σωτηρίαν τῆς καταψύξεως, τῷ αὐτῷ

ὀργάνῳ χρῆται πρὸς ἄμφω ταῦτα ἡ φύσις, καθάπερ ἐνίοις

τῇ γλώττῃ πρός τε τοὺς χυμοὺς καὶ πρὸς τὴν ἐρμηνείαν,

20 οὕτω τοῖς ἔχουσι τὸν πνεύμονα τῷ καλουμένῳ στόματι πρός

τε τὴν τῆς τροφῆς ἐργασίαν καὶ τὴν ἐκπνοὴν καὶ τὴν ἀναπνοήν.

τοῖς δὲ μὴ ἔχουσι πνεύμονα μηδ' ἀναπνέουσι τὸ μὲν

στόμα πρὸς τὴν ἐργασίαν τῆς τροφῆς, πρὸς δὲ τὴν κατάψυξιν

τοῖς δεομένοις καταψύξεως ἡ τῶν βραγχίων ὑπάρχει

25 φύσις. πῶς μὲν οὖν ἡ τῶν εἰρημένων ὀργάνων δύναμις

ποιεῖ τὴν κατάψυξιν, ὕστερον ἐροῦμεν· πρὸς δὲ τὸ τὴν τροφὴν

μὴ διακωλύειν παραπλησίως τοῖς τ' ἀναπνέουσι συμβαίνει

καὶ τοῖς δεχομένοις τὸ ὑγρόν· οὔτε γὰρ ἀναπνέοντες

ἅμα καταδέχονται τὴν τροφήν (εἰ δὲ μή, συμβαίνει πνίγεσθαι

30 παρεισιούσης τῆς τροφῆς ἢ τῆς ξηρᾶς ἢ τῆς ὑγρᾶς

ἐπὶ τὸν πνεύμονα διὰ τῆς ἀρτηρίας· προτέρα γὰρ κεῖται ἡ

ἀρτηρία τοῦ οἰσοφάγου, δι' οὗ ἡ τροφὴ πορεύεται εἰς τὴν καλουμένην

κοιλίαν· τοῖς μὲν οὖν τετράποσι καὶ ἐναίμοις ἔχει

ἡ ἀρτηρία οἷον πῶμα τὴν ἐπιγλωττίδα· τοῖς δ' ὄρνισι καὶ

16Every animal in order to exist requires nutriment, in order to prevent itself from dying, refrigeration; and so Nature employs the same organ for both purposes. For, as in some cases the tongue serves both for discerning tastes and for speech, 20so in animals with lungs the mouth is employed both in working up the food and in the passage of the breath outwards and inwards. In lungless and non-respiring animals it is employed in working up the food, while in those of them that require refrigeration it is the gills that are created for this purpose.
25We shall state further on how it is that these organs have the faculty of producing refrigeration. But to prevent their food from impeding these operations there is a similar contrivance in the respiring animals and in those that admit water. At the moment of respiration they do not take in food, for otherwise suffocation results owing to the food, 30whether liquid or dry, slipping in through the windpipe and lying on the lung.
The windpipe is situated before the oesophagus, through which food passes into what is called the stomach, but in quadrupeds which are sanguineous there is, as it were, a lid over the windpipe-the epiglottis.

476b

1 τῶν τετραπόδων τοῖς ᾠοτόκοις οὐκ ἔπεστιν, ἀλλὰ τῇ συναγωγῇ

τὸ αὐτὸ ποιοῦσιν· δεχόμενα γὰρ τὴν τροφὴν τὰ μὲν

συνάγει, τὰ δ' ἐπιτίθησι τὴν ἐπιγλωττίδα· προελθούσης δὲ

τὰ μὲν ἐπαίρει, τὰ δὲ διοίγει καὶ καταδέχεται τὸ πνεῦμα

5 πρὸς τὴν κατάψυξιν)· τά τ' ἔχοντα βράγχια, ἀφέντα

διὰ τούτων τὸ ὑγρόν, διὰ τοῦ στόματος καταδέχεται τὴν

τροφήν· ἀρτηρίαν μὲν γὰρ οὐκ ἔχουσιν, ὥστε ταύτῃ μὲν οὐθὲν

ἂν βλάπτοιντο ὑπὸ τῆς τοῦ ὑγροῦ παρεμπτώσεως, ἀλλ'

εἰς τὴν κοιλίαν εἰσιόντος· διὸ ταχεῖαν ποιεῖται τὴν ἄφεσιν

10 καὶ τὴν λῆψιν τῆς τροφῆς, καὶ τοὺς ὀδόντας ὀξεῖς ἔχουσι,

καὶ καρχαρόδοντες σχεδὸν πάντες εἰσίν· οὐ γὰρ ἐνδέχεται

λεαίνειν τὴν τροφήν.

1In birds and oviparous quadrupeds this covering is absent, but its office is discharged by a contraction of the windpipe. The latter class contract the windpipe when swallowing their food; the former close down the epiglottis. When the food has passed, the epiglottis is in the one case raised, and in the other the windpipe is expanded, and the air enters to effect refrigeration.
5In animals with gills the water is first discharged through them and then the food passes in through the mouth; they have no windpipe and hence can take no harm from liquid lodging in this organ, only from its entering the stomach. For these reasons the expulsion of water and 10the seizing of their food is rapid, and their teeth are sharp and in almost all cases arranged in a saw-like fashion, for they are debarred from chewing their food.

Chapter 18 (476b13–477a10)

Περὶ δὲ τὰ κητώδη τῶν ἐνύδρων ἀπορήσειεν ἄν τις,

ἔχει δὲ κἀκεῖνα κατὰ λόγον, οἷον περί τε τοὺς δελφῖνας

15 καὶ τὰς φαλαίνας, καὶ τῶν ἄλλων ὅσα ἔχει τὸν καλούμενον

αὐλόν. ταῦτα γὰρ ἄποδα μέν ἐστιν, ἔχοντα δὲ πνεύμονα

δέχεται τὴν θάλατταν. αἴτιον δὲ τούτου τὸ νῦν εἰρημένον·

οὐ γὰρ καταψύξεως ἕνεκεν δέχεται τὸ ὑγρόν. τοῦτο μὲν

γὰρ γίνεται αὐτοῖς ἀναπνέουσιν· ἔχουσι γὰρ πνεύμονα. διὸ

20 καὶ καθεύδουσιν ὑπερέχοντα τὸ στόμα, καὶ ῥέγχουσιν οἵ γε

δελφῖνες. ἔτι δὲ κἂν ληφθῶσιν ἐν τοῖς δικτύοις, ταχὺ ἀποπνίγονται

διὰ τὸ μὴ ἀναπνεῖν· διὸ καὶ ἐπιπολάζοντα φαίνεται

τὰ τοιαῦτα ἐπὶ τῆς θαλάττης διὰ τὴν ἀναπνοήν. ἀλλ' ἐπειδὴ

ἀναγκαῖον ποιεῖσθαι τὴν τροφὴν ἐν ὑγρῷ, ἀναγκαῖον δεχόμενα

25 τὸ ὑγρὸν ἀφιέναι, καὶ διὰ τοῦτ' ἔχουσι πάντα τὸν

αὐλόν· δεξάμενα γὰρ τὸ ὕδωρ, ὥσπερ οἱ ἰχθύες κατὰ τὰ

βράγχια, ταῦτα κατὰ τὸν αὐλὸν ἀνασπᾷ τὸ ὕδωρ. σημεῖον

δὲ καὶ ἡ θέσις τοῦ αὐλοῦ· πρὸς οὐθὲν γὰρ περαίνει τῶν

ἐναίμων, ἀλλὰ πρὸ τοῦ ἐγκεφάλου τὴν θέσιν ἔχει [καὶ

30 ἀφίησι τὸ ὕδωρ]. διὰ ταὐτὸ δὲ τοῦτο δέχεται καὶ τὰ μαλάκια

τὸ ὕδωρ καὶ τὰ μαλακόστρακα, λέγω δ' οἷον τοὺς

καλουμένους καράβους καὶ τοὺς καρκίνους. καταψύξεως μὲν

γὰρ αὐτῶν οὐδὲν τυγχάνει δεόμενον· ὀλιγόθερμον γάρ ἐστι

καὶ ἄναιμον ἕκαστον αὐτῶν, ὥσθ' ἱκανῶς καταψύχεται ὑπὸ

13Among water-animals the cetaceans may give rise to some perplexity, though they too can be rationally explained.
Examples of such animals are dolphins 15and whales, and all others that have a blowhole. They have no feet, yet possess a lung though admitting the sea-water. The reason for possessing a lung is that which we have now stated [refrigeration]; the admission of water is not for the purpose of refrigeration. That is effected by respiration, for they have a lung. 20Hence they sleep with their head out of the water, and dolphins, at any rate, snore. Further, if they are entangled in nets they soon die of suffocation owing to lack of respiration, and hence they can be seen to come to the surface owing to the necessity of breathing. But, since they have to feed in the water, they must admit it, 25and it is in order to discharge this that they all have a blow-hole; after admitting the water they expel it through the blow-hole as the fishes do through the gills. The position of the blow-hole is an indication of this, for it leads to none of the organs which are charged with blood; but it lies before the brain and thence discharges water.
30It is for the very same reason that molluscs and crustaceans admit water-I mean such animals as Carabi and Carcini. For none of these is refrigeration a necessity, for in every case they have little heat and are bloodless, and hence are sufficiently cooled by the surrounding water.

477a

1 τοῦ περιέχοντος ὑγροῦ, ἀλλὰ διὰ τὴν τροφὴν <ἀφίησι τὸ ὕδωρ>,

ὅπως μὴ ἅμα δεχομένοις εἰσρέῃ τὸ ὑγρόν. τὰ μὲν οὖν μαλακόστρακα,

οἷον οἵ τε καρκίνοι καὶ οἱ κάραβοι, παρὰ τὰ δασέα

ἀφιᾶσι τὸ ὕδωρ διὰ τῶν ἐπιπτυγμάτων, σηπίαι δὲ καὶ πολύποδες

5 διὰ τοῦ κοίλου τοῦ ὑπὲρ τῆς καλουμένης κεφαλῆς. γέγραπται

δὲ περὶ αὐτῶν δι' ἀκριβείας μᾶλλον ἐν ταῖς περὶ

τῶν ζῴων ἱστορίαις. περὶ μὲν οὖν τοῦ δέχεσθαι τὸ ὑγρόν,

εἴρηται ὅτι συμβαίνει διὰ κατάψυξιν καὶ διὰ τὸ δεῖν δέχεσθαι

τὴν τροφὴν ἐκ τοῦ ὑγροῦ τὰ τὴν φύσιν ὄντα τῶν ζῴων

10 ἔνυδρα.

1But in feeding they admit water, and hence must expel it in order to prevent its being swallowed simultaneously with the food. Thus crustaceans, like the Carcini and Carabi, discharge water through the folds beside their shaggy parts, while cuttlefish and 5the polyps employ for this purpose the hollow above the head. There is, however, a more precise account of these in the History of Animals.
Thus it has been explained that the cause of the admission of the water is refrigeration, and the fact that animals 10constituted for a life in water must feed in it.

Chapter 19 (477a11–31)

Περὶ δὲ τῆς καταψύξεως, τίνα γίνεται τρόπον τοῖς τ'

ἀναπνέουσι καὶ τοῖς ἔχουσι βράγχια, μετὰ ταῦτα λεκτέον.

ὅτι μὲν οὖν ἀναπνέουσιν ὅσα πνεύμονα τῶν ζῴων ἔχουσι, πρότερον

εἴρηται. διὰ τί δὲ τοῦτο τὸ μόριον ἔχουσιν ἔνια, καὶ

15 διὰ τί τὰ ἔχοντα δεῖται τῆς ἀναπνοῆς, αἴτιον τοῦ μὲν ἔχειν

ὅτι τὰ τιμιώτερα τῶν ζῴων πλείονος τετύχηκε θερμότητος·

ἅμα γὰρ ἀνάγκη καὶ ψυχῆς τετυχηκέναι τιμιωτέρας· τιμιώτερα

γὰρ ταῦτα τῆς φύσεως τῆς τῶν ψυχρῶν. διὸ

καὶ τὰ μάλιστα ἔναιμον ἔχοντα τὸν πνεύμονα καὶ θερμὸν

20 μείζονά τε τοῖς μεγέθεσι, καὶ τό γε καθαρωτάτῳ καὶ πλείστῳ

κεχρημένον αἵματι τῶν ζῴων ὀρθότατόν ἐστιν, ὁ ἄνθρωπος,

καὶ τὸ ἄνω πρὸς τὸ τοῦ ὅλου ἄνω ἔχει μόνον διὰ τὸ

τοιοῦτον ἔχειν τοῦτο τὸ μόριον. ὥστε τῆς οὐσίας καὶ τούτῳ καὶ

τοῖς ἄλλοις θετέον αἴτιον αὐτὸ καθάπερ ὁτιοῦν ἄλλο τῶν

25 μορίων. ἔχει μὲν οὖν ἕνεκα τούτου. τὴν δ' ἐξ ἀνάγκης καὶ τῆς

κινήσεως αἰτίαν καὶ τὰ τοιαῦτα δεῖ νομίζειν συνιστάναι ζῷα

καθάπερ καὶ μὴ τοιαῦτα πολλὰ συνέστηκεν· τὰ μὲν γὰρ ἐκ

γῆς πλείονος συνέστηκεν, οἷον τὸ τῶν φυτῶν γένος, τὰ δ' ἐξ

ὕδατος, οἷον τὸ τῶν ἐνύδρων· τῶν δὲ πτηνῶν καὶ πεζῶν τὰ

30 μὲν ἐξ ἀέρος τὰ δ' ἐκ πυρός. ἕκαστα δ' ἐν τοῖς οἰκείοις τόποις

ἔχει τὴν τάξιν αὐτῶν.

11An account must next be given of refrigeration and the manner in which it occurs in respiring animals and those possessed of gills. We have already said that all animals with lungs respire. The reason why some creatures have this organ, 15and why those having it need respiration, is that the higher animals have a greater proportion of heat, for at the same time they must have been assigned a higher soul and they have a higher nature than plants. Hence too those with most blood and most warmth in the lung 20are of greater size, and animal in which the blood in the lung is purest and most plentiful is the most erect, namely man; and the reason why he alone has his upper part directed to the upper part of the universe is that he possesses such a lung. Hence this organ as much as any other must be assigned to the essence of the animal both in man and in other cases.
25This then is the purpose of refrigeration. As for the constraining and efficient cause, we must believe that it created animals like this, just as it created many others also not of this constitution. For some have a greater proportion of earth in their composition, like plants, and others, e.g. aquatic animals, contain a larger amount of water; while winged and terrestrial animals 30have an excess of air and fire respectively. It is always in the region proper to the element preponderating in the scheme of their constitution that things exist.

Chapter 20 (477a32–478a10)

Ἐμπεδοκλῆς δ' οὐ καλῶς τοῦτ' εἴρηκε, φάσκων τὰ θερμότατα

32Empedocles is then in error when he says that those animals which have the most warmth and fire live in the water to counterbalance the excess of heat in their constitution, in order that, since they are deficient in cold and fluid, they may be kept in life by the contrary character of the region they occupy; for water has less heat than air.

477b

1 καὶ πῦρ ἔχοντα πλεῖστον τῶν ζῴων ἔνυδρα εἶναι,

φεύγοντα τὴν ὑπερβολὴν τῆς ἐν τῇ φύσει θερμότητος, ὅπως

ἐπειδὴ τοῦ ψυχροῦ καὶ τοῦ ὑγροῦ ἐλλείπει, κατὰ τὸν τόπον

ἀνασῴζηται, ἐναντίον ὄντα· θερμὸν γὰρ εἶναι τὸ ὑγρὸν ἧττον

5 τοῦ ἀέρος. ὅλως μὲν οὖν ἄτοπον πῶς ἐνδέχεται γενόμενον ἕκαστον

αὐτῶν ἐν τῷ ξηρῷ μεταβάλλειν τὸν τόπον εἰς τὸ ὑγρόν

(σχεδὸν γὰρ καὶ ἄποδα τὰ πλεῖστα αὐτῶν ἐστιν)· ὁ δὲ τὴν ἐξ

ἀρχῆς αὐτῶν σύστασιν λέγων γενέσθαι μὲν ἐν τῷ ξηρῷ

φησι, φεύγοντα δ' ἐλθεῖν εἰς τὸ ὕδωρ. ἔτι δ' οὐδὲ φαίνεται

10 θερμότερα ὄντα τῶν πεζῶν· τὰ μὲν γὰρ ἄναιμα πάμπαν,

τὰ δ' ὀλίγαιμα αὐτῶν ἐστιν. ἀλλὰ ποῖα μὲν δεῖ λέγειν θερμὰ

καὶ ψυχρά, καθ' αὑτὰ τὴν ἐπίσκεψιν εἴληφεν· περὶ δ'

ἧς αἰτίας εἴρηκεν Ἐμπεδοκλῆς, τῇ μὲν ἔχει τὸ ζητούμενον

λόγον, οὐ μὴν ὅ γέ φησιν ἐκεῖνος ἀληθές. τῶν μὲν γὰρ

15 ἕξεων τοὺς τὰς ὑπερβολὰς ἔχοντας οἱ ἐναντίοι τόποι καὶ ὧραι

σῴζουσιν, ἡ δὲ φύσις ἐν τοῖς οἰκείοις σῴζεται μάλιστα τόποις.

οὐ γὰρ ταὐτὸν ἥ θ' ὕλη τῶν ζῴων ἐξ ἧς ἐστιν ἕκαστον,

καὶ αἱ ἕξεις καὶ διαθέσεις αὐτῆς. λέγω δ' οἷον εἴ τι ἐκ κηροῦ

συστήσειεν ἡ φύσις, οὐκ ἂν ἐν θερμῷ θεῖσα διέσωσεν, οὐδ'

20 εἴ τι ἐκ κρυστάλλου· ἐφθάρη γὰρ ἂν ταχὺ διὰ τοὐναντίον·

τήκει γὰρ τὸ θερμὸν τὸ ὑπὸ τοῦ ἐναντίου συστάν. οὐδ' εἴ τι ἐξ

ἁλὸς ἢ νίτρου συνέστησεν, οὐκ ἂν εἰς ὑγρὸν φέρουσα κατέθηκεν·

φθείρει γὰρ τὰ ὑπὸ ξηροῦ συστάντα τὸ ὑγρόν. εἰ

οὖν ὕλη πᾶσι τοῖς σώμασι τὸ ὑγρὸν καὶ τὸ ξηρόν, εὐλόγως

25 τὰ μὲν ἐξ ὑγροῦ [καὶ ψυχροῦ] συστάντα ἐν ὑγροῖς ἐστι [καὶ εἰ

ψυχρά, ἔσται ἐν ψυχρῷ], τὰ δ' ἐκ ξηροῦ ἐν ξηρῷ. διὰ τοῦτο

τὰ δένδρα οὐκ ἐν ὕδατι φύεται, ἀλλ' ἐν γῇ. καίτοι τοῦ

αὐτοῦ λόγου ἐστὶν εἰς τὸ ὕδωρ, διὰ τὸ εἶναι αὐτὰ ὑπέρξηρα,

ὥσπερ τὰ ὑπέρπυρά φησιν ἐκεῖνος· οὐ γὰρ διὰ τὸ ψυχρὸν <ἂν>

30 ἦλθεν εἰς αὐτό, ἀλλ' ὅτι ὑγρόν. αἱ μὲν οὖν φύσεις τῆς ὕλης,

ἐν οἵῳπερ τόπῳ εἰσί, τοιαῦται οὖσαι τυγχάνουσιν, αἱ μὲν ἐν

ὕδατι ὑγραί, αἱ δ' ἐν τῇ γῇ ξηραί, αἱ δ' ἐν τῷ ἀέρι θερμαί·

1But it is wholly absurd that the water-animals should in every case originate on dry land, and afterwards change their place of abode to the water; for they 5are almost all footless. He, however, when describing their original structure says that, though originating on dry land, they have abandoned it and migrated to the water. But again it is evident that 10they are not warmer than land-animals, for in some cases they have no blood at all, in others little.
The question, however, as to what sorts of animals should be called warm and what cold, has in each special case received consideration. Though in one respect there is reason in the explanation which Empedocles aims at establishing, yet his account is not correct. 15Excess in a bodily state is cured by a situation or season of opposite character, but the constitution is best maintained by an environment akin to it. There is a difference between the material of which any animal is constituted and the states and dispositions of that material. For example, if nature were to constitute a thing of wax or of ice, she would not preserve it by putting it in a hot place, 20for the opposing quality would quickly destroy it, seeing that heat dissolves that which cold congeals. Again, a thing composed of salt or nitre would not be taken and placed in water, for fluid dissolves that of which the consistency is due to the hot and the dry.
Hence if the fluid and the dry supply the material for all bodies, it is reasonable that things the composition of which is due to the fluid and the cold 25should have liquid for their medium [and, if they are cold, they will exist in the cold], while that which is due to the dry will be found in the dry. Thus trees grow not in water but on dry land. But the same theory would relegate them to the water, on account of their excess of dryness, just as it does the things that are excessively fiery. They would migrate thither not on account of its cold 30but owing to its fluidity.
Thus the natural character of the material of objects is of the same nature as the region in which they exist; the liquid is found in liquid, the dry on land, the warm in air.

478a

1 αἱ μέντοι ἕξεις αἱ μὲν ὑπερβάλλουσαι θερμότητι ἐν

ψυχρῷ, αἱ δὲ τῇ ψυχρότητι ἐν θερμῷ τιθέμεναι σῴζονται

μᾶλλον· ἐπανισοῖ γὰρ εἰς τὸ μέτριον ὁ τόπος τὴν τῆς ἕξεως

ὑπερβολήν. τοῦτο μὲν οὖν δεῖ ζητεῖν ἐν τοῖς οἰκείοις τόποις

5 ἑκάστης ὕλης καὶ κατὰ τὰς μεταβολὰς τῆς κοινῆς ὥρας·

τὰς μὲν γὰρ ἕξεις ἐνδέχεται τοῖς τόποις ἐναντίας εἶναι, τὴν

δ' ὕλην ἀδύνατον. ὅτι μὲν οὖν οὐ διὰ θερμότητα τῆς φύσεως

τὰ μὲν ἔνυδρα τὰ δὲ πεζὰ τῶν ζῴων ἐστί, καθάπερ Ἐμπεδοκλῆς

φησιν, τοσαῦτ' εἰρήσθω, καὶ διότι τὰ μὲν οὐκ ἔχει

10 πνεύμονα τὰ δὲ ἔχει.

1With regard, however, to states of body, a cold situation has, on the other hand, a beneficial effect on excess of heat, and a warm environment on excess of cold, for the region reduces to a mean the excess in the bodily condition. The regions 5appropriate to each material and the revolutions of the seasons which all experience supply the means which must be sought in order to correct such excesses; but, while states of the body can be opposed in character to the environment, the material of which it is composed can never be so. This, then, is a sufficient explanation of why it is not owing to the heat in their constitution that some animals are aquatic, others terrestrial, as Empedocles maintains, and of why 10some possess lungs and others do not.

Chapter 21 (478a11–25)

Διὰ τί δὲ τὰ ἔχοντα δέχεται τὸν ἀέρα καὶ ἀναπνέουσι,

καὶ μάλιστ' αὐτῶν ὅσα ἔχουσιν ἔναιμον, αἴτιον τοῦ μὲν ἀναπνεῖν

ὁ πνεύμων σομφὸς ὢν καὶ συρίγγων πλήρης. καὶ ἐναιμότατον

δὴ μάλιστα τοῦτο τὸ μόριον τῶν καλουμένων σπλάγχνων.

15 ὅσα δὴ ἔχει ἔναιμον αὐτό, ταχείας μὲν δεῖται τῆς

καταψύξεως διὰ τὸ μικρὰν εἶναι τὴν ῥοπὴν τοῦ ψυχικοῦ πυρός,

εἴσω δ' εἰσιέναι διὰ παντὸς διὰ τὸ πλῆθος τοῦ αἵματος

καὶ τῆς θερμότητος. ταῦτα δ' ἀμφότερα ὁ μὲν ἀὴρ δύναται

ῥᾳδίως ποιεῖν· διὰ γὰρ τὸ λεπτὴν ἔχειν τὴν φύσιν διὰ

20 παντός τε καὶ ταχέως διαδυόμενος διαψύχει· τὸ δ' ὕδωρ

τοὐναντίον. καὶ διότι δὴ μάλιστ' ἀναπνέουσι τὰ ἔχοντα τὸν

πνεύμονα ἔναιμον, ἐκ τούτων δῆλον· τό τε γὰρ θερμότερον

πλείονος δεῖται τῆς καταψύξεως, ἅμα δὲ καὶ πρὸς τὴν ἀρχὴν

τῆς θερμότητος τὴν ἐν τῇ καρδίᾳ πορεύεται τὸ πνεῦμα

25 ῥᾳδίως.

11The explanation of the admission of air and respiration in those animals in which a lung is found, and especially in those in which it is full of blood, is to be found in the fact that it is of a spongy nature and full of tubes, and that it is the most fully charged with blood of all the visceral organs. 15All animals with a full-blooded lung require rapid refrigeration because there is little scope for deviation from the normal amount of their vital fire; the air also must penetrate all through it on account of the large quantity of blood and heat it contains. But both these operations can be easily performed by air, for, being of a subtle nature, it penetrates 20everywhere and that rapidly, and so performs its cooling function; but water has the opposite characteristics.
The reason why animals with a full-blooded lung respire most is hence manifest; the more heat there is, the greater is the need for refrigeration, and at the same time 25breath can easily pass to the source of heat in the heart.

Chapter 22 (478a26–478b21)

Ὃν δὲ τρόπον ἡ καρδία τὴν σύντρησιν ἔχει πρὸς τὸν

πνεύμονα, δεῖ θεωρεῖν ἔκ τε τῶν ἀνατεμνομένων καὶ τῶν

ἱστοριῶν τῶν περὶ τὰ ζῷα γεγραμμένων. καταψύξεως μὲν

οὖν ὅλως ἡ τῶν ζῴων δεῖται φύσις διὰ τὴν ἐν τῇ καρδίᾳ τῆς

30 ψυχῆς ἐμπύρευσιν. ταύτην δὲ ποιεῖται διὰ τῆς ἀναπνοῆς

ὅσα μὴ μόνον ἔχουσι καρδίαν ἀλλὰ καὶ πνεύμονα τῶν ζῴων.

τὰ δὲ καρδίαν μὲν ἔχοντα, πνεύμονα δὲ μή, καθάπερ οἱ

ἰχθύες διὰ τὸ ἔνυδρον αὐτῶν τὴν φύσιν εἶναι, τῷ ὕδατι ποιοῦνται

τὴν κατάψυξιν διὰ τῶν βραγχίων. ὡς δ' ἡ θέσις ἔχει

35 τῆς καρδίας πρὸς τὰ βράγχια, πρὸς μὲν τὴν ὄψιν ἐκ τῶν

26In order to understand the way in which the heart is connected with the lung by means of passages, we must consult both dissections and the account in the History of Animals. The universal cause of the need which the animal has for refrigeration, is the union of the soul with fire that takes place in the heart. 30Respiration is the means of effecting refrigeration, of which those animals make use that possess a lung as well as a heart.
35But when they, as for example the fishes, which on account of their aquatic nature have no lung, possess the latter organ without the former, the cooling is effected through the gills by means of water.

478b

1 ἀνατομῶν δεῖ θεωρεῖν, πρὸς δ' ἀκρίβειαν ἐκ τῶν ἱστοριῶν· ὡς

δ' ἐν κεφαλαίοις εἰπεῖν καὶ νῦν, ἔχει τόνδε τὸν τρόπον. δόξειε

μὲν γὰρ <ἂν> οὐχ ὡσαύτως ἔχειν τὴν θέσιν ἡ καρδία τοῖς τε

πεζοῖς τῶν ζῴων καὶ τοῖς ἰχθύσιν, ἔχει δ' ὡσαύτως. ᾗ γὰρ

5 νεύουσι τὰς κεφαλάς, ἐνταῦθ' ἡ καρδία τὸ ὀξὺ ἔχει. ἐπεὶ δὲ

οὐχ ὡσαύτως αἱ κεφαλαὶ νεύουσι τοῖς τε πεζοῖς τῶν ζῴων

καὶ τοῖς ἰχθύσι, πρὸς τὸ στόμα ἡ καρδία τὸ ὀξὺ ἔχει. τείνει

δ' ἐξ ἄκρου τῆς καρδίας αὐλὸς φλεβονευρώδης εἰς τὸ

μέσον, ᾗ συνάπτουσιν ἀλλήλοις πάντα τὰ βράγχια. μέγιστος

10 μὲν οὖν οὗτός ἐστιν, ἔνθεν δὲ καὶ ἔνθεν τῆς καρδίας καὶ

ἕτεροι τείνουσιν εἰς ἄκρον ἑκάστου τῶν βραγχίων, δι' ὧν ἡ

κατάψυξις γίνεται πρὸς τὴν καρδίαν, διαυλωνίζοντος ἀεὶ

τοῦ ὕδατος διὰ τῶν βραγχίων. ὡσαύτως δὲ τοῖς ἀναπνέουσιν

ὁ θώραξ ἄνω καὶ κάτω κινεῖται πολλάκις δεχομένων τὸ

15 πνεῦμα καὶ ἐξιέντων, ὡς τὰ βράγχια τοῖς ἰχθύσιν. καὶ τὰ

μὲν ἀναπνέοντα ἐν ὀλίγῳ ἀέρι καὶ τῷ αὐτῷ ἀποπνίγονται·

ταχέως γὰρ ἑκάτερον αὐτῶν γίνεται θερμόν (θερμαίνει γὰρ

ἡ τοῦ αἵματος θίξις ἑκάτερον), θερμὸν δ' ὂν [τὸ αἷμα] κωλύει

τὴν κατάψυξιν· καὶ μὴ δυναμένων κινεῖν τῶν μὲν ἀναπνεόντων

20 τὸν πνεύμονα τῶν δ' ἐνύδρων τὰ βράγχια διὰ πάθος

ἢ διὰ γῆρας, τότε συμβαίνειν <δεῖ> τὴν τελευτήν.

1For ocular evidence as to how the heart is situated relatively to the gills we must employ dissections, and for precise details we must refer to Natural History. As a summarizing statement, however, and for present purposes, the following is the account of the matter.
It might appear that the heart has not the same position in terrestrial animals and fishes, but the position really is identical, for 5the apex of the heart is in the direction in which they incline their heads. But it is towards the mouth in fishes that the apex of the heart points, seeing that they do not incline their heads in the same direction as land-animals do. Now from the extremity of the heart a tube of a sinewy, arterial character runs to the centre where the gills all join. 10This then is the largest of those ducts, but on either side of the heart others also issue and run to the extremity of each gill, and by means of the ceaseless flow of water through the gills, effect the cooling which passes to the heart.
In similar fashion as the fish move their gills, respiring animals with rapid action raise and let fall the chest 15according as the breath is admitted or expelled. If air is limited in amount and unchanged they are suffocated, for either medium, owing to contact with the blood, rapidly becomes hot. The heat of the blood counteracts the refrigeration and, when respiring animals can 20no longer move the lung aquatic animals their gills, whether owing to discase or old age, their death ensues.

Chapter 23 (478b22–479a28)

Ἔστι μὲν οὖν πᾶσι τοῖς ζῴοις κοινὸν γένεσις καὶ θάνατος,

οἱ δὲ τρόποι διαφέρουσι τῷ εἴδει· οὐ γὰρ ἀδιάφορος ἡ

φθορά, ἀλλ' ἔχει τι κοινόν. θάνατος δ' ἐστὶν ὁ μὲν βίαιος ὁ

25 δὲ κατὰ φύσιν, βίαιος μὲν ὅταν ἡ ἀρχὴ ἔξωθεν ᾖ, κατὰ

φύσιν δ' ὅταν ἐν αὐτῷ, καὶ ἡ τοῦ μορίου σύστασις ἐξ ἀρχῆς

τοιαύτη, ἀλλὰ μὴ ἐπίκτητόν τι πάθος. τοῖς μὲν οὖν φυτοῖς

αὔανσις, ἐν δὲ τοῖς ζῴοις καλεῖται τοῦτο γῆρας. ἔστι δὲ θάνατος

καὶ ἡ φθορὰ πᾶσιν ὁμοίως τοῖς μὴ ἀτελέσιν· τούτοις

30 δὲ παρομοίως μέν, ἄλλον δὲ τρόπον. ἀτελῆ δὲ λέγω οἷον

τά τε ᾠὰ καὶ τὰ σπέρματα τῶν φυτῶν, ὅσα ἄρριζα. πᾶσι

μὲν οὖν ἡ φθορὰ γίνεται διὰ θερμοῦ τινος ἔκλειψιν, τοῖς δὲ

τελείοις, ἐν ᾧ τῆς οὐσίας ἡ ἀρχή. αὕτη δ' ἐστίν, ὥσπερ

εἴρηται πρότερον, ἐν ᾧ τό τε ἄνω καὶ τὸ κάτω συνάπτει,

35 τοῖς μὲν φυτοῖς μέσον βλαστοῦ καὶ ῥίζης, τῶν δὲ ζῴων τοῖς

22To be born and to die are common to all animals, but there are specifically diverse ways in which these phenomena occur; of destruction there are different types, though yet something is common to them all.
There is violent death 25and again natural death, and the former occurs when the cause of death is external, the latter when it is internal, and involved from the beginning in the constitution of the organ, and not an affection derived from a foreign source. In the case of plants the name given to this is withering, in animals senility. Death and decay pertain to all things that are not imperfectly developed; 30to the imperfect also they may be ascribed in nearly the same but not an identical sense. Under the imperfect I class eggs and seeds of plants as they are before the root appears.
35It is always to some lack of heat that death is due, and in perfect creatures the cause is its failure in the organ containing the source of the creature's essential nature.

479a

1 μὲν ἐναίμοις ἡ καρδία, τοῖς δ' ἀναίμοις τὸ ἀνάλογον. τούτων

δ' ἔνια δυνάμει πολλὰς ἀρχὰς ἔχουσιν, οὐ μέντοι γε

ἐνεργείᾳ. διὸ καὶ τῶν ἐντόμων ἔνια διαιρούμενα ζῶσι, καὶ

τῶν ἐναίμων ὅσα μὴ ζωτικὰ λίαν εἰσὶ πολὺν χρόνον ζῶσιν

5 ἐξῃρημένης τῆς καρδίας, οἷον αἱ χελῶναι, καὶ κινοῦνται τοῖς

ποσίν, ἐπόντων τῶν χελωνίων, διὰ τὸ μὴ συγκεῖσθαι τὴν

φύσιν αὐτῶν εὖ, παραπλησίως δὲ τοῖς ἐντόμοις. ἡ δ' ἀρχὴ

τῆς ζωῆς ἐκλείπει τοῖς ἔχουσιν ὅταν μὴ καταψύχηται τὸ

θερμὸν τὸ κοινωνοῦν αὐτῆς· καθάπερ γὰρ εἴρηται πολλάκις,

10 συντήκεται αὐτὸ ὑφ' αὑτοῦ. ὅταν οὖν τοῖς μὲν ὁ πνεύμων τοῖς

δὲ τὰ βράγχια σκληρύνηται, διὰ χρόνου μῆκος ξηραινομένων

τοῖς μὲν τῶν βραγχίων τοῖς δὲ τοῦ πνεύμονος, καὶ γινομένων

γεηρῶν, οὐ δύναται ταῦτα τὰ μόρια κινεῖν οὐδ' αἴρειν

καὶ συνάγειν, τέλος δὲ γιγνομένης ἐπιτάσεως καταμαραίνεται

15 τὸ πῦρ. διὸ καὶ μικρῶν παθημάτων ἐπιγινομένων ἐν τῷ

γήρᾳ ταχέως τελευτῶσιν· διὰ γὰρ τὸ ὀλίγον εἶναι τὸ θερμόν,

ἅτε τοῦ πλείστου διαπεπνευκότος ἐν τῷ πλήθει τῆς ζωῆς, ἥτις

ἂν ἐπίτασις γένηται τοῦ μορίου, ταχέως ἀποσβέννυται· ὥσπερ

γὰρ ἀκαριαίας καὶ μικρᾶς ἐν αὐτῷ φλογὸς ἐνούσης διὰ μικρὰν

20 κίνησιν ἀποσβέννυται. διὸ καὶ ἄλυπός ἐστιν ὁ ἐν τῷ

γήρᾳ θάνατος· οὐδενὸς γὰρ βιαίου πάθους αὐτοῖς συμβαίνοντος

τελευτῶσιν, ἀλλ' ἀναίσθητος ἡ τῆς ψυχῆς ἀπόλυσις γίνεται

παντελῶς. καὶ τῶν νοσημάτων ὅσα ποιοῦσι τὸν πνεύμονα

σκληρὸν ἢ φύμασιν ἢ περιττώμασιν ἢ θερμότητος νοσηματικῆς

25 ὑπερβολῇ, καθάπερ ἐν τοῖς πυρετοῖς, πυκνὸν τὸ πνεῦμα

ποιοῦσι διὰ τὸ μὴ δύνασθαι τὸν πνεύμονα μακρὰν αἴρειν

ἄνω καὶ συνίζειν. τέλος δ', ὅταν μηκέτι δύνωνται κινεῖν,

τελευτῶσιν ἀποπνεύσαντες.

1This member is situate, as has been said, at the junction of the upper and lower parts; in plants it is intermediate between the root and the stem, in sanguineous animals it is the heart, and in those that are bloodless the corresponding part of their body. But some of these animals have potentially many sources of life, though in actuality they possess only one. This is why some insects live when divided, and why, even among sanguineous animals, all whose vitality is not intense live for a long time 5after the heart has been removed. Tortoises, for example, do so and make movements with their feet, so long as the shell is left, a fact to be explained by the natural inferiority of their constitution, as it is in insects also.
The source of life is lost to its possessors when the heat with which it is bound up is no longer tempered by cooling, for, as I have often remarked, 10it is consumed by itself. Hence when, owing to lapse of time, the lung in the one class and the gills in the other get dried up, these organs become hard and earthy and incapable of movement, and cannot be expanded or contracted. Finally things come to a climax, and the fire goes out from exhaustion.
15Hence a small disturbance will speedily cause death in old age.
Little heat remains, for the most of it has been breathed away in the long period of life preceding, and hence any increase of strain on the organ quickly causes extinction. It is just as though the heart contained a tiny feeble flame which the slightest movement puts out. 20Hence in old age death is painless, for no violent disturbance is required to cause death, and there is an entire absence of feeling when the soul's connexion is severed.
All diseases which harden the lung by forming tumours or waste residues, or by excess of morbid heat, 25as happens in fevers, accelerate the breathing owing to the inability of the lung to move far either upwards or downwards.
Finally, when motion is no longer possible, the breath is given out and death ensues.

Chapter 24 (479a29–479b7)

Γένεσις μὲν οὖν ἐστιν ἡ πρώτη μέθεξις ἐν τῷ θερμῷ τῆς

30 θρεπτικῆς ψυχῆς, ζωὴ δ' ἡ μονὴ ταύτης. νεότης δ' ἐστὶν ἡ

τοῦ πρώτου καταψυκτικοῦ μορίου αὔξησις, γῆρας δ' ἡ τούτου

φθίσις, ἀκμὴ δὲ τὸ τούτων μέσον. τελευτὴ δὲ καὶ φθορὰ

βίαιος μὲν ἡ τοῦ θερμοῦ σβέσις καὶ μάρανσις (φθαρείη γὰρ

29Generation is the initial participation, mediated by warm substance, in the nutritive soul, and life is the maintenance of this participation.
30Youth is the period of the growth of the primary organ of refrigeration, old age of its decay, while the intervening time is the prime of life.

479b

1 ἂν δι' ἀμφοτέρας ταύτας τὰς αἰτίας), ἡ δὲ κατὰ φύσιν τοῦ

αὐτοῦ τούτου μάρανσις διὰ χρόνου μῆκος γινομένη καὶ τελειότητα·

τοῖς μὲν οὖν φυτοῖς αὔανσις, ἐν δὲ τοῖς ζῴοις καλεῖται

θάνατος. τούτου δ' ὁ μὲν ἐν γήρᾳ θάνατος μάρανσις τοῦ

5 μορίου δι' ἀδυναμίαν τοῦ καταψύχειν ὑπὸ γήρως. τί μὲν οὖν

ἐστι γένεσις καὶ ζωὴ καὶ θάνατος, καὶ διὰ τίνας αἰτίας

ὑπάρχουσι τοῖς ζῴοις, εἴρηται.

1A violent death or dissolution consists in the extinction or exhaustion of the vital heat (for either of these may cause dissolution), while natural death is the exhaustion of the heat owing to lapse of time, and occurring at the end of life. In plants this is to wither, in animals to die. Death, in old age, is the exhaustion due to inability on the part of the organ, 5owing to old age, to produce refrigeration. This then is our account of generation and life and death, and the reason for their occurrence in animals.

Chapter 25 (479b8–16)

Δῆλον δ' ἐκ τούτων καὶ διὰ τίν' αἰτίαν τοῖς μὲν ἀναπνέουσι

τῶν ζῴων ἀποπνίγεσθαι συμβαίνει ἐν τῷ ὑγρῷ, τοῖς

10 δ' ἰχθύσιν ἐν τῷ ἀέρι· τοῖς μὲν γὰρ διὰ τοῦ ὕδατος ἡ κατάψυξις

γίνεται, τοῖς δὲ διὰ τοῦ ἀέρος, ὧν ἑκάτερα στερίσκεται

μεταβάλλοντα τοὺς τόπους. ἡ δ' αἰτία τῆς κινήσεως

τοῖς μὲν τῶν βραγχίων τοῖς δὲ τοῦ πνεύμονος, ὧν αἰρομένων

καὶ συνιζόντων τὰ μὲν ἐκπνέουσι καὶ εἰσπνέουσι τὰ δὲ

15 δέχονται τὸ ὑγρὸν καὶ ἐξιᾶσιν, ἔτι δ' ἡ σύστασις τοῦ ὀργάνου,

τόνδ' ἔχει τὸν τρόπον.

Τρία

8It is hence also clear why respiring animals are suffocated in water and fishes in air. For it is by water in the latter class, 10by air in the former that refrigeration is effected, and either of these means of performing the function is removed by a change of environment.
There is also to be explained in either case the cause of the cause of the motion of the gills and of the lungs, the rise and fall of which effects the admission and expulsion of the breath or of water. The following, moreover, is 15the manner of the constitution of the organ.

Chapter 26 (479b17–480a15)

δ' ἐστὶ τὰ συμβαίνοντα περὶ τὴν καρδίαν, ἃ δοκεῖ

τὴν αὐτὴν φύσιν ἔχειν, ἔχει δ' οὐ τὴν αὐτήν, πήδησις

καὶ σφυγμὸς καὶ ἀναπνοή. πήδησις μὲν οὖν ἐστι σύνωσις

20 τοῦ θερμοῦ τοῦ ἐν αὐτῇ διὰ κατάψυξιν περιττωματικὴν ἢ

συντηκτικήν, οἷον ἐν τῇ νόσῳ τῇ καλουμένῃ παλμῷ, καὶ ἐν

ἄλλαις δὲ νόσοις, καὶ ἐν τοῖς φόβοις δέ· καὶ γὰρ οἱ φοβούμενοι

καταψύχονται τὰ ἄνω, τὸ δὲ θερμὸν ὑποφεῦγον καὶ

συστελλόμενον ποιεῖ τὴν πήδησιν, εἰς μικρὸν συνωθούμενον

25 οὕτως ὥστ' ἐνίοτ' ἀποσβέννυσθαι τὰ ζῷα καὶ ἀποθνήσκειν

διὰ φόβον καὶ διὰ πάθος νοσηματικόν. ἡ δὲ συμβαίνουσα

σφύξις τῆς καρδίας, ἣν ἀεὶ φαίνεται ποιουμένη συνεχῶς,

ὁμοία φύμασίν ἐστιν, ἣν ποιοῦνται κίνησιν μετ' ἀλγηδόνος

διὰ τὸ παρὰ φύσιν εἶναι τῷ αἵματι τὴν μεταβολήν· γίνεται

30 δὲ μέχρις οὗ ἂν πυωθῇ πεφθέν. ἔστι δ' ὅμοιον ζέσει τοῦτο

τὸ πάθος· ἡ γὰρ ζέσις γίνεται πνευματουμένου τοῦ ὑγροῦ

ὑπὸ τοῦ θερμοῦ· αἴρεται γὰρ διὰ τὸ πλείω γίνεσθαι τὸν ὄγκον.

παῦλα δ' ἐν μὲν τοῖς φύμασιν, ἐὰν μὴ διαπνεύσῃ, παχυτέρου

17In connexion with the heart there are three phenomena, which, though apparently of the same nature, are really not so, namely palpitation, pulsation, and respiration.
Palpitation is the rushing together of the hot substance in the heart 20owing to the chilling influence of residual or waste products. It occurs, for example, in the ailment known as 'spasms' and in other diseases.
It occurs also in fear, for when one is afraid the upper parts become cold, and the hot substance, fleeing away, by its concentration in the heart produces palpitation. It is crushed into so small a space 25that sometimes life is extinguished, and the animals die of the fright and morbid disturbance.
The beating of the heart, which, as can be seen, goes on continuously, is similar to the throbbing of an abscess. That, however, is accompanied by pain, because the change produced in the blood is unnatural, 30and it goes on until the matter formed by concoction is discharged. There is a similarity between this phenomenon and that of boiling; for boiling is due to the volatilization of fluid by heat and the expansion consequent on increase of bulk.

480a

1 γινομένου τοῦ ὑγροῦ, σῆψις, τῇ δὲ ζέσει ἡ ἔκπτωσις

διὰ τῶν ὁριζόντων. ἐν δὲ τῇ καρδίᾳ ἡ τοῦ ἀεὶ προσιόντος ἐκ

τῆς τροφῆς ὑγροῦ διὰ τῆς θερμότητος ὄγκωσις ποιεῖ σφυγμόν,

αἰρομένη πρὸς τὸν ἔσχατον χιτῶνα τῆς καρδίας. καὶ

5 τοῦτ' ἀεὶ γίνεται συνεχῶς· ἐπιρρεῖ γὰρ ἀεὶ τὸ ὑγρὸν συνεχῶς,

ἐξ οὗ γίνεται ἡ τοῦ αἵματος φύσις. πρῶτον γὰρ ἐν

τῇ καρδίᾳ δημιουργεῖται· δῆλον δ' ἐν τῇ γενέσει ἐξ ἀρχῆς·

οὔπω γὰρ διωρισμένων τῶν φλεβῶν φαίνεται ἔχουσα αἷμα.

καὶ διὰ τοῦτο σφύζει μᾶλλον τοῖς νεωτέροις τῶν πρεσβυτέρων·

10 γίνεται γὰρ ἡ ἀναθυμίασις πλείων τοῖς νεωτέροις. καὶ

σφύζουσιν αἱ φλέβες πᾶσαι, καὶ ἅμα ἀλλήλαις, διὰ τὸ

ἠρτῆσθαι ἐκ τῆς καρδίας. κινεῖ δ' ἀεί· ὥστε κἀκεῖναι ἀεί,

καὶ ἅμα ἀλλήλαις, ὅτε κινεῖ. ἀναπήδησις μὲν οὖν ἐστιν ἡ

γινομένη ἄντωσις πρὸς τὴν τοῦ ψυχροῦ σύνωσιν, σφύξις δ' ἡ

15 τοῦ ὑγροῦ θερμαινομένου πνευμάτωσις.

1But in an abscess, if there is no evaporation through the walls, the process terminates in suppuration due to the thickening of the liquid, while in boiling it ends in the escape of the fluid out of the containing vessel.
In the heart the beating is produced by the heat expanding the fluid, of which the food furnishes a constant supply. It occurs when the fluid rises to the outer wall of the heart, 5and it goes on continuously; for there is a constant flow of the fluid that goes to constitute the blood, it being in the heart that the blood receives its primary elaboration.
That this is so we can perceive in the initial stages of generation, for the heart can be seen to contain blood before the veins become distinct.
This explains why pulsation in youth exceeds that in older people, 10for in the young the formation of vapour is more abundant.
All the veins pulse, and do so simultaneously with each other, owing to their connexion with the heart. The heart always beats, and hence they also beat continuously and simultaneously with each other and with it.
Palpitation, then, is the recoil of the heart against the compression due to cold; 15and pulsation is the volatilization of the heated fluid.

Chapter 27 (480a16–480b30)

Ἡ δ' ἀναπνοὴ γίνεται αὐξανομένου τοῦ θερμοῦ ἐν ᾧ ἡ

ἀρχὴ ἡ θρεπτική. καθάπερ γὰρ καὶ τἆλλα δεῖται τροφῆς,

κἀκεῖνο, καὶ τῶν ἄλλων μᾶλλον· καὶ γὰρ τοῖς ἄλλοις

ἐκεῖνο τῆς τροφῆς αἴτιόν ἐστιν. ἀνάγκη δὴ πλέον γινόμενον

20 αἴρειν τὸ ὄργανον. δεῖ δ' ὑπολαβεῖν τὴν σύστασιν τοῦ ὀργάνου

παραπλησίαν μὲν εἶναι ταῖς φύσαις ταῖς ἐν τοῖς χαλκείοις

(οὐ πόρρω γὰρ οὔθ' ὁ πνεύμων οὔθ' ἡ καρδία τοῦ προσδέξασθαι

σχῆμα τοιοῦτον), διπλοῦν δ' εἶναι τὸ τοιοῦτον· δεῖ γὰρ

ἐν τῷ μέσῳ τὸ θρεπτικὸν εἶναι τῆς ψυκτικῆς δυνάμεως.

25 αἴρεται μὲν οὖν πλεῖον γενόμενον, αἰρομένου δ' ἀναγκαῖον

αἴρεσθαι καὶ τὸ περιέχον αὐτὸ μόριον. ὅπερ φαίνονται ποιεῖν

οἱ ἀναπνέοντες· αἴρουσι γὰρ τὸν θώρακα διὰ τὸ τὴν ἀρχὴν

τὴν ἐνοῦσαν αὐτῷ τοῦ τοιούτου μορίου ταὐτὸ τοῦτο ποιεῖν·

αἰρομένου δέ, καθάπερ εἰς τὰς φύσας, ἀναγκαῖον εἰσφρεῖν

30 τὸν ἀέρα τὸν θύραθεν ψυχρὸν ὄντα, καὶ καταψύχοντα

16Respiration takes place when the hot substance which is the seat of the nutritive principle increases. For it, like the rest of the body, requires nutrition, and more so than the members, for it is through it that they are nourished. 20But when it increases it necessarily causes the organ to rise. This organ we must to be constructed like the bellows in a smithy, for both heart and lungs conform pretty well to this shape. Such a structure must be double, for the nutritive principle must be situated in the centre of the natural force.
25Thus on increase of bulk expansion results, which necessarily causes the surrounding parts to rise. Now this can be seen to occur when people respire; they raise their chest because the motive principle of the organ described resident within the chest causes an identical expansion of this organ. When it dilates the outer air must rush in as into a bellows, 30and, being cold, by its chilling influence reduces by extinction the excess of the fire.

480b

1 σβεννύναι τὴν ὑπεροχὴν τὴν τοῦ πυρός. ὥσπερ δ' αὐξανομένου

ᾔρετο τοῦτο τὸ μόριον, καὶ φθίνοντος ἀναγκαῖον συνίζειν,

καὶ συνίζοντος ἐξιέναι τὸν ἀέρα τὸν εἰσελθόντα πάλιν, εἰςιόντα

μὲν ψυχρὸν ἐξιόντα δὲ θερμὸν διὰ τὴν ἁφὴν τοῦ θερμοῦ

5 τοῦ ἐνόντος ἐν τῷ μορίῳ τούτῳ, καὶ μάλιστα τοῖς τὸν

πνεύμονα ἔναιμον ἔχουσιν· εἰς πολλοὺς γὰρ οἷον αὐλῶνας

τὰς σύριγγας ἐμπίπτειν τὰς ἐν τῷ πνεύμονι, ὧν παρ' ἑκάστην

παρατέτανται φλέβες, ὥστε δοκεῖν ὅλον εἶναι τὸν πνεύμονα

πλήρη αἵματος. καλεῖται δ' ἡ μὲν εἴσοδος τοῦ ἀέρος

10 ἀναπνοή, ἡ δ' ἔξοδος ἐκπνοή. καὶ ἀεὶ δὴ τοῦτο γίνεται συνεχῶς,

ἕως περ ἂν ζῇ καὶ κινῇ τοῦτο τὸ μόριον συνεχῶς·

καὶ διὰ τοῦτο ἐν τῷ ἀναπνεῖν καὶ ἐκπνεῖν ἐστι τὸ ζῆν. τὸν

αὐτὸν δὲ τρόπον καὶ τοῖς ἰχθύσιν ἡ κίνησις γίνεται τῶν

βραγχίων. αἰρομένου γὰρ τοῦ θερμοῦ τοῦ ἐν τῷ αἵματι

15 διὰ τῶν μορίων αἴρονται καὶ τὰ βράγχια, καὶ διιᾶσι τὸ

ὕδωρ· κατιόντος δὲ πρὸς τὴν καρδίαν διὰ τῶν πόρων καὶ

καταψυχομένου συνίζουσι, καὶ ἀφιᾶσι τὸ ὕδωρ. ἀεὶ δ' αἰρομένου

τοῦ ἐν τῇ καρδίᾳ ἀεὶ δέχεται, <καὶ ἀφίησι> πάλιν καταψυχομένου.

διὸ κἀκείνοις τοῦ ζῆν καὶ μὴ ζῆν τὸ τέλος ἐστὶν ἐν

20 τῷ ἀναπνεῖν, καὶ τούτοις ἐν τῷ δέχεσθαι τὸ ὑγρόν.

περὶ μὲν οὖν ζωῆς καὶ θανάτου καὶ τῶν συγγενῶν ταύτης

τῆς σκέψεως σχεδὸν εἴρηται περὶ πάντων. περὶ δὲ

ὑγιείας καὶ νόσου οὐ μόνον ἐστὶν ἰατροῦ ἀλλὰ καὶ τοῦ φυσικοῦ

μέχρι του τὰς αἰτίας εἰπεῖν. ᾗ δὲ διαφέρουσι καὶ ᾗ διαφέροντα

25 θεωροῦσιν, οὐ δεῖ λανθάνειν, ἐπεὶ ὅτι γε σύνορος ἡ

πραγματεία μέχρι τινός ἐστι, μαρτυρεῖ τὸ γινόμενον· τῶν

τε γὰρ ἰατρῶν ὅσοι κομψοὶ καὶ περίεργοι λέγουσί τι περὶ

φύσεως καὶ τὰς ἀρχὰς ἐκεῖθεν ἀξιοῦσι λαμβάνειν, καὶ τῶν

περὶ φύσεως πραγματευθέντων οἱ χαριέστατοι σχεδὸν τελευτῶσιν

30 εἰς τὰς ἀρχὰς τὰς ἰατρικάς.

1But, as the increase of bulk causes the organ to dilate, so diminution causes contraction, and when it collapses the air which entered must pass out again. When it enters the air is cold, but on issuing it is warm owing to its contact with the heat 5resident in this organ, and this is specially the case in those animals that possess a full-blooded lung. The numerous canal-like ducts in the lung, into which it passes, have each a blood-vessel lying alongside, so that the whole lung is thought to be full of blood. The inward passage of the air is called 10respiration, the outward expiration, and this double movement goes on continuously just so long as the animal lives and keeps this organ in continuous motion; it is for this reason that life is bound up with the passage of the breath outwards and inwards.
It is in the same way that the motion of the gills in fishes takes place. When the hot substance in the blood throughout the members rises, 15the gills rise too, and let the water pass through, but when it is chilled and retreats through its channels to the heart, they contract and eject the water. Continually as the heat in the heart rises, continually on being chilled it returns thither again. Hence, as in respiring animals life and death are bound up with respiration, so in the other animals class 20they depend on the admission of water.
Our discussion of life and death and kindred topics is now practically complete. But health and discase also claim the attention of the scientist, and not mercly of the physician, in so far as an account of their causes is concerned. The extent to which these two differ and investigate diverse provinces 25must not escape us, since facts show that their inquiries are, to a certain extent, at least conterminous. For physicians of culture and refinement make some mention of natural science, and claim to derive their principles from it, while the most accomplished investigators into nature generally push their studies so far as 30to conclude with an account of medical principles.