§17Ἔστι μὲν οὖν πᾶσι τοῖς ζῴοις κοινὸν γένεσις καὶ θάνατος, οἱ δὲ τρόποι διαφέρουσι τῷ εἴδει· οὐ γὰρ ἀδιάφορος ἡ φθορά, ἀλλ’ ἔχει τι κοινόν.
Generation and death, then, are common to all animals, but the modes differ in species; for destruction is not without differences, though it has something common.
Θάνατος δ’ ἐστὶν ὁ μὲν βίαιος ὁ δὲ κατὰ φύσιν, βίαιος μὲν ὅταν ἡ ἀρχὴ ἔξωθεν ᾖ, κατὰ φύσιν δ’ ὅταν ἐν αὐτῷ.
And death is on the one hand violent, and on the other hand natural; violent when the source is from without, and natural when it is in the animal itself.
Καὶ ἡ τοῦ μορίου σύστασις ἐξ ἀρχῆς τοιαύτη, ἀλλὰ μὴ ἐπίκτητόν τι πάθος.
And [it is natural when] the constitution of the part is such from the beginning, and not some acquired affection.
Τοῖς μὲν οὖν φυτοῖς αὔανσις, ἐν δὲ τοῖς ζῴοις καλεῖται τοῦτο γῆρας.
In plants, then, this is called drying up, but in animals it is called old age.
Ἔστι δὲ θάνατος καὶ ἡ φθορὰ πᾶσιν ὁμοίως τοῖς μὴ ἀτελέσιν· τούτοις δὲ παρομοίως μέν, ἄλλον δὲ τρόπον.
And death and destruction occur similarly to all that are not incomplete; and to these in a similar but different manner.
Ἀτελῆ δὲ λέγω οἷον τά τε ᾠὰ καὶ τὰ σπέρματα τῶν φυτῶν, ὅσα ἄρριζα.
By incomplete I mean, for example, eggs and the seeds of plants, whichever are rootless.
Πᾶσι μἐν οὖν ἡ φθορὰ γίνεται διὰ θερμοῦ τινὸς ἔκλειψιν, τοῖς δὲ τελείοις, ἐν ᾧ τῆς οὐσίας ἡ ἀρχή.
Now, for all, destruction occurs through the waning of some heat, but for the complete ones, in that part where the source of their essence resides.
Αὕτη δ’ ἐστίν, ὥσπερ εἴρηται πρότερον, ἐν ᾧ τό τε ἄνω καὶ τὸ κάτω συνάπτει, τοῖς μὲν φυτοῖς μέσον βλαστοῦ καὶ ῥίζης, τῶν δὲ ζῴων τοῖς μὲν ἐναίμοις ἡ καρδία, τοῖς δ’ ἀναίμοις τὸ ἀνάλογον.
And this is, as has been said before, where the upper and the lower connect, in plants the middle between the shoot and the root, and in animals, in those with blood the heart, and in those without blood the analogue.
Τούτων δ’ ἔνια δυνάμει πολλὰς ἀρχὰς ἔχουσιν, οὐ μέντοι γε ἐνεργείᾳ.
But some of these have potentially many sources, though not indeed actually.
Διὸ καὶ τῶν ἐντόμων ἔνια διαιρούμενα ζῶσι, καὶ τῶν ἐναίμων ὅσα μὴ ζωτικὰ λίαν εἰσί, πολὺν χρόνον ζῶσιν 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.
Therefore, some of the insects live when divided, and of those with blood, whichever are not excessively vital live for a long time when the heart has been removed, as for instance tortoises, and they move with their feet, with their shells still on, because their nature is not well compacted, but is very similar to insects.
Ἡ δ’ ἀρχὴ τῆς ζωῆς ἐκλείπει τοῖς ἔχουσιν, ὅταν μὴ καταψύχηται τὸ θερμὸν τὸ κοινωνοῦν αὐτῆς.
But the source of life wanes in those that have it, when the heat that shares in it is not cooled.
Καθάπερ γὰρ εἴρηται πολλάκις, συντήκεται αὐτὸ ὑφ’ αὑτοῦ.
For as has been said many times, it consumes itself by itself.
Ὅταν οὖν τοῖς μὲν ὁ πλεύμων τοῖς δὲ τὰ βράγχια σκληρύνηται, διὰ χρόνου μῆκος ξηραινομένων τοῖς μὲν τῶν βραγχίων τοῖς δὲ τοῦ πλεύμονος, καὶ γινομένων γεηρῶν, οὐ δύναται ταῦτα τὰ μόρια κινεῖν οὐδ’ αἴρειν καὶ συνάγειν.
When, therefore, in some the lung and in others the gills become hardened, as through length of time those of the gills in some and of the lung in others are dried up and become earthy, they are unable to move these parts or to raise and contract them.
Τέλος δὲ γινομένης ἐπιτάσεως καταμαραίνεται τὸ πῦρ.
And finally, as tension increases, the fire is extinguished.
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 κίνησιν ἀποσβέννυται.
Therefore also when small affections supervene in old age they die quickly; for because the heat is little, since most of it has evaporated in the abundance of life, whatever tension occurs in the part, it is quickly extinguished; for it is as if a tiny and small flame were inside it, which is extinguished by a small movement.
Διὸ καὶ ἄλυπός ἐστιν ὁ ἐν τῷ γήρᾳ θάνατος· οὐδενὸς γὰρ βιαίου πάθους αὐτοῖς συμβαίνοντος τελευτῶσιν, ἀλλ’ ἀναίσθητος ἡ τῆς ψυχῆς ἀπόλυσις γίνεται παντελῶς.
Therefore also death in old age is painless; for they die without any violent affection happening to them, but the release of the soul occurs completely imperceptibly.
Καὶ τῶν νοσημάτων ὅσα ποιοῦσι τὸν πνεύμονα σκληρὸν ἢ φύμασιν ἢ περιττώμασιν ἢ θερμότητος νοσηματικῆς ὑπερβολῇ, καθάπερ ἐν τοῖς πυρετοῖς, πυκνὸν τὸ πνεῦμα ποιοῦσι διὰ τὸ μὴ δύνασθαι τὸν πνεύμονα μακρὰν αἴρειν ἄνω καὶ συνίζειν.
And of diseases, those which make the lung hard, either by tumors or residues or by excess of morbid heat, as in fevers, make the breath frequent because the lung is unable to raise itself far upward and collapse.
Τέλος δ’, ὅταν μηκέτι δύνωνται κινεῖν, τελευτῶσιν ἀποπνεύσαντες.
And finally, when they can no longer move it, they die, having breathed their last.