§1#2Οὐκ ἐνδέχεται δὲ οὐδὲ θάτερον τούτων ἀεὶ ὑπάρχειν τῷ αὐτῷ, οἷον ἀεί τι γένος ζῴων καθεύδειν ἢ ἀεί τι ἐγρηγορέναι.
it is also not possible for either of these to belong to the same thing forever, for instance, for some class of animals to be always sleeping or for some to be always awake.
Ἔτι ὅσων ἐστί τι ἔργον κατὰ φύσιν, ὅταν ὑπερβάλλῃ τὸν χρόνον ᾧ δύναται χρόνῳ τι ποιεῖν, ἀνάγκη ἀδυνατεῖν, οἷον τὰ ὄμματα ὁρῶντα καὶ παύεσθαι τοῦτο ποιοῦντα, ὁμοίως δὲ καὶ χεῖρα καὶ ἄλλο πᾶν οὗ ἐστί τι ἔργον.
Furthermore, in the case of all things that have a certain natural function, when they exceed the time during which they are able to perform it, they must of necessity become incapable, as the eyes become incapable by seeing and cease doing this, and likewise also the hand and everything else that has a certain function.
Εἰ δή τινός ἐστιν ἔργον τὸ αἰσθάνεσθαι, καὶ τοῦτο ἂν ὑπερβάλλῃ ὅσον ἦν χρόνον δυνάμενον αἰσθάνεσθαι συνεχῶς, ἀδυνατήσει καὶ οὐκέτι τοῦτο ποιήσει.
If, then, perceiving is the function of some part, and if this exceeds the length of time for which it was capable of perceiving continuously, it will become incapable and will no longer do this.
Εἰ τοίνυν τὸ ἐγρηγορέναι ὥρισται τῷ λελύσθαι τὴν αἴσθησιν, τῶν δ’ ἐναντίων τὸ μὲν ἀνάγκη παρεῖναι τὸ δ’ οὔ, τὸ δ’ ἐγρηγορέναι τῷ καθεύδειν ἐναντίον, καὶ ἀναγκαῖον παντὶ θάτερον ὑπάρχειν, ἀναγκαῖον ἂν εἴη καθεύδειν.
If, therefore, being awake is defined by the perception being released, and of contraries one must of necessity be present and the other not, and being awake is contrary to sleeping, and it is necessary for one of the two to belong to every animal, it would be necessary to sleep.
Εἰ οὖν τὸ τοιοῦτον πάθος ὕπνος, τοῦτο δ’ ἐστὶν ἀδυναμία δι’ ὑπερβολὴν τοῦ ἐγρηγορέναι, ἡ δὲ τοῦ ἐγρηγορέναι ὑπερβολὴ ὁτὲ μὲν νοσώδης ὁτὲ δ’ ἄνευ νόσου γίνεται, ὥστε καὶ ἡ ἀδυναμία καὶ ἡ διάλυσις ὡσαύτως ἔσται, ἀνάγκη πᾶν τὸ ἐγρηγορὸς ἐνδέχεσθαι καθεύδειν· ἀδύνατον γὰρ ἀεὶ ἐνεργεῖν.
If, then, such an affection is sleep, and this is an incapacity due to an excess of waking, and the excess of waking occurs sometimes with disease and sometimes without disease, so that the incapacity and the relaxation will occur likewise, it is necessary that everything that is awake is capable of sleeping; for it is impossible to be always active.
Ὁμοίως δὲ οὐδὲ καθεύδειν οὐδὲν ἀεὶ ἐνδέχεται.
And likewise, it is not possible for anything to be always asleep either.
Ὁ γὰρ ὕπνος τι τοῦ αἰσθητικοῦ μορίου ἐστίν, οἷον δεσμὸς καὶ ἀκινησία τις, ὥστ’ ἀνάγκη πᾶν τὸ καθεῦδον ἔχειν τὸ αἰσθητικὸν μόριον.
For sleep is a certain state of the sensitive part, as it were a certain bond and immobilization, so that it is necessary for everything that sleeps to have the sensitive part.
Αἰσθητικὸν δὲ τὸ δυνατὸν αἰσθάνεσθαι κατ’ ἐνέργειαν· ἐνεργεῖν δὲ τῇ αἰσθήσει κυρίως καὶ ἁπλῶς ἀδύνατον καθεῦδον ἅμα· διὸ ἀναγκαῖον ὕπνον πάντα ἐγερτὸν εἶναι.
And that which is sensitive is that which is capable of perceiving in activity; but it is impossible to perceive in the proper and simple sense while sleeping at the same time; wherefore it is necessary for all sleep to be capable of waking.
Τὰ μὲν οὖν ἄλλα σχεδὸν πάντα δῆλα κοινωνοῦνθ’ ὕπνου, καὶ πλωτὰ καὶ πτηνὰ καὶ πεζά· καὶ γὰρ τὰ τῶν ἰχθύων γένη πάντα καὶ τὰ τῶν μαλακίων ὦπται καθεύδοντα, καὶ τἆλλα πάνθ’ ὅσα περ ἔχει ὀφθαλμούς· καὶ γὰρ τὰ σκληρόφθαλμα φανερὰ καὶ τὰ ἔντομα κοιμώμενα· βραχύυπνα δὲ τὰ τοιαῦτα πάντα, διὸ καὶ λάθοι ἄν τινα πολλάκις πότερον μετέχουσι τοῦ καθεύδειν ἢ οὔ.
Now, almost all other animals are clearly participants in sleep, whether they are swimming, flying, or walking; for all classes of fish and mollusks have been observed sleeping, and all other things that have eyes; for hard-eyed animals and insects are clearly seen sleeping; but all such things have short sleep, wherefore it may often escape the notice of some whether they participate in sleeping or not.
Τῶν δ’ ὀστρακοδέρμων κατὰ μὲν τὴν αἴσθησιν οὐδέ πω γέγονε φανερὸν εἰ καθεύδουσιν· εἰ δέ τῳ πιθανὸς ὁ λεχθεὶς λόγος, τούτῳ πεισθήσεται.
On the other hand, in the case of testaceans, it is not yet clear from observation whether they sleep; but if the stated argument is persuasive to anyone, he will be convinced by this.
Ὅτι μὲν οὖν ὕπνου κοινωνεῖ τὰ ζῷα πάντα, φανερὸν ἐκ τούτων· τῷ γὰρ αἴσθησιν ἔχειν ὥρισται τὸ ζῷον, τῆς δ’ αἰσθήσεως τρόπον τινὰ τὴν μὲν ἀκινησίαν καὶ οἷον δεσμὸν τὸν ὕπνον εἶναί φαμεν, τὴν δὲ λύσιν καὶ τὴν ἄνεσιν ἐγρήγορσιν.
That all animals, then, participate in sleep is clear from these considerations; for the animal is defined by having perception, and we say that sleep is in a certain way the immobilization and, as it were, a bond of perception, while waking is its release and relaxation.
Τῶν δὲ φυτῶν οὐδὲν οἷόν τε κοινωνεῖν οὐδετέρου τούτων τῶν παθημάτων.
But none of the plants can participate in either of these affections.
Ἄνευ μὲν γὰρ αἰσθήσεως οὐχ ὑπάρχει οὔθ’ ὕπνος οὔτ’ ἐγρήγορσις· οἷς δ’ αἴσθησις ὑπάρχει, καὶ τὸ λυπεῖσθαι καὶ τὸ χαίρειν· οἷς δὲ ταῦτα, καὶ ἐπιθυμία.
For without perception there is neither sleep nor waking; but to those to which perception belongs, there belong also both pain and pleasure; and to those to which these belong, there belongs also desire.
Τοῖς δὲ φυτοῖς οὐδὲν ὑπάρχει τούτων.
But plants have none of these.
Σημεῖον δ’ ὅτι καὶ τὸ ἔργον τὸ αὑτοῦ ποιεῖ τὸ θρεπτικὸν μόριον ἐν τῷ καθεύδειν μᾶλλον ἢ ἐν τῷ ἐγρηγορέναι· τρέφεται γὰρ καὶ αὐξάνεται τότε μᾶλλον, ὡς οὐδὲν προσδεόμενα πρὸς ταῦτα τῆς αἰσθήσεως.
And it is a sign of this that the nutritive part performs its own function during sleep more than during waking; for animals are nourished and grow more at that time, since they have no further need of perception for these processes.