§2.11Ἀλλὰ καθόλου περὶ τῶν ἐμφαινομένων καὶ ἀνακλάσεως οὐδέν πω δῆλον ἦν, ὡς ἔοικεν.
But generally, concerning images and reflection, nothing was yet clear, as it seems.
Ἄτοπον δὲ καὶ τὸ μὴ ἐπελθεῖν αὐτῷ ἀπορῆσαι διὰ τί ὁ ὀφθαλμὸς ὁρᾷ μόνον, τῶν δ’ ἄλλων οὐδὲν ἐν οἷς ἐμφαίνεται τὰ εἴδωλα.
And it is strange that it did not occur to him to wonder why only the eye sees, while none of the other things in which images appear can see.
Τὸ μὲν οὖν τὴν ὄψιν εἶναι ὕδατος ἀληθὲς μέν, οὐ μέντοι συμβαίνει τὸ ὁρᾶν ᾗ ὕδωρ ἀλλ’ ᾗ διαφανές· ὃ καὶ ἐπὶ τοῦ ἀέρος κοινόν ἐστιν.
Therefore, while it is true that sight is of water, seeing does not happen to it insofar as it is water, but insofar as it is transparent; and this is common also to air.
§2.12Ἀλλ’ εὐφυλακτότερον καὶ εὐπιλητότερον τὸ ὕδωρ τοῦ ἀέρος· διόπερ ἡ κόρη καὶ τὸ ὄμμα ὕδατός ἐστιν.
But water is easier to preserve and more easily condensed than air; therefore the pupil and the eye consist of water.
Τοῦτο δὲ καὶ ἐπ’ αὐτῶν τῶν ἔργων δῆλον· φαίνεται γὰρ ὕδωρ τὸ ἐκρέον διαφθειρομένων, καὶ ἔν γε τοῖς πάμπαν ἐμβρύοις τῇ ψυχρότητι ὑπερβάλλον καὶ τῇ λαμπρότητι.
And this is clear also from the actual facts; for the fluid that flows out when they are destroyed appears to be water, and in very early embryos it is outstanding in coldness and brightness.
§2.13Καὶ τὸ λευκὸν τοῦ ὄμματος ἐν τοῖς ἔχουσιν αἷμα πῖον καὶ λιπαρόν· ὅπερ διὰ τοῦτ’ ἐστί, πρὸς τὸ διαμένειν τὸ ὑγρὸν ἄπηκτον.
And the white of the eye in blooded animals is fat and oily; which is so for this reason, in order that the fluid may remain unfrozen.
Καὶ διὰ τοῦτο τοῦ σώματος ἀρριγότατον ὁ ὀφθαλμός ἐστιν· οὐδεὶς γάρ πω τὸ ἐντὸς τῶν βλεφάρων ἐρρίγωσεν.
And because of this, the eye is the part of the body least sensitive to cold; for no one has ever felt cold inside the eyelids.
Τῶν δ’ ἀναίμων σκληρόδερμοι οἱ ὀφθαλμοί εἰσι, καὶ τοῦτο ποιεῖ τὴν σκέπην.
But the eyes of bloodless animals have hard skin, and this provides the protection.
§2.14Ἄλογον δὲ ὅλως τὸ ἐξιόντι τινὶ τὴν ὄψιν ὁρᾶν, καὶ ἀποτείνεσθαι μέχρι τῶν ἄστρων, ἢ μέχρι τινὸς ἐξιοῦσαν συμφύεσθαι, καθάπερ λέγουσί τινες.
And it is completely unreasonable that sight sees by something going out, and that it stretches as far as the stars, or that, as some say, as it goes out it coalesces up to a certain point.
Τούτου μὲν γὰρ βέλτιον τὸ ἐν ἀρχῇ συμφύεσθαι τοῦ ὄμματος.
For it is better than this that the coalescence should occur at the beginning of the eye.
Ἀλλὰ καὶ τοῦτο εὔηθες· τό τε γὰρ συμφύεσθαι τί ἐστι φωτὶ πρὸς φῶς;
Yet even this is foolish; for what is the coalescence of light with light?
Ἣ πῶς οἷόν θ’ ὑπάρχειν;
Or how is it possible to exist?
Οὐ γὰρ τῷ τυχόντι συμφύεται τὸ τυχόν.
For any chance thing does not coalesce with any other.
§2.15Τό τ’ ἐντὸς τῷ ἐκτὸς πῶς;
And how does the internal coalesce with the external?
Ἡ γὰρ μῆνιγξ μεταξύ ἐστιν.
For the membrane is in between.
Περὶ μὲν οὖν τοῦ ἄνευ φωτὸς μὴ ὁρᾶν εἴρηται ἐν ἄλλοις· ἀλλ’ εἴτε φῶς εἴτ’ ἀήρ ἐστι τὸ μεταξὺ τοῦ ὁρωμένου καὶ τοῦ ὄμματος, ἡ διὰ τούτου κίνησίς ἐστιν ἡ ποιοῦσα τὸ ὁρᾶν.
Now, concerning the fact that one does not see without light, it has been said elsewhere; but whether it is light or air that is between the thing seen and the eye, the movement through this is what produces seeing.
Καὶ εὐλόγως τὸ ἐντός ἐστιν ὕδατος· διαφανὲς γὰρ τὸ ὕδωρ.
And it is reasonable that the inside consists of water; for water is transparent.
§2.16Ὁρᾶται δὲ ὥσπερ καὶ ἔξω οὐκ ἄνευ φωτός, οὕτω καὶ ἐντός· διαφανὲς ἄρα δεῖ εἶναι.
And just as seeing is not without light outside, so also inside; therefore it must be transparent.
Καὶ ἀνάγκη ὕδωρ εἶναι, ἐπειδὴ οὐκ ἀήρ.
And it must be water, since it is not air.
Οὐ γὰρ ἐπὶ τοῦ ἐσχάτου ὄμματος ἡ ψυχὴ ἢ τῆς ψυχῆς τὸ αἰσθητήριόν ἐστιν, ἀλλὰ δῆλον ὅτι ἐντός· διόπερ ἀνάγκη διαφανὲς εἶναι καὶ δεκτικὸν φωτὸς τὸ ἐντὸς τοῦ ὄμματος.
For the soul, or the sensory organ of the soul, is not on the surface of the eye, but is clearly within; therefore the inside of the eye must be transparent and receptive of light.
§2.17Καὶ τοῦτο καὶ ἐπὶ τῶν συμβαινόντων δῆλον· ἤδη γάρ τισι πληγεῖσιν ἐν πολέμῳ παρὰ τὸν κρόταφον οὕτως ὥστ’ ἐκτμηθῆναι τοὺς πόρους τοῦ ὄμματος, ἔδοξε γενέσθαι σκότος ὥσπερ λύχνου ἀποσβεσθέντος, διὰ τὸ οἷον λαμπτῆρά τινα ἀποτμηθῆναι τὸ διαφανές, τὴν καλουμένην κόρην.
And this is clear also from what happens; for when some who were struck in war near the temple in such a way that the passages of the eye were cut off, it seemed that darkness occurred as if a lamp were extinguished, because the transparent part, the so-called pupil, was cut off like a kind of lantern.
§2.18Ὤστ’ εἴπερ τούτων τι συμβαίνει, καθάπερ λέγομεν, φανερὸν ὡς δεῖ τοῦτον τὸν τρόπον ἀποδιδόναι καὶ προσάπτειν ἕκαστον τῶν αἰσθητηρίων ἑνὶ τῶν στοιχείων.
So if any of these things happen as we say, it is clear that we must in this way assign and attach each of the sense-organs to one of the elements.
Τοῦ μὲν ὄμματος τὸ ὁρατικὸν ὕδατος ὑποληπτέον, ἀέρος δὲ τὸ τῶν ψόφων αἰσθητικόν, πυρὸς δὲ τὴν ὄσφρησιν.
We must assume that the seeing part of the eye is of water, the sensory organ of sounds of air, and smell of fire.
§2.19Ὃ γὰρ ἐνεργείᾳ ἡ ὄσφρησις, τοῦτο δυνάμει τὸ ὀσφραντικόν· τὸ γὰρ αἰσθητὸν ἐνεργεῖν ποιεῖ τὴν αἴσθησιν, ὥσθ’ ὑπάρχειν ἀνάγκη αὐτὴν δυνάμει πρότερον.
For what smell is in activity, that the organ of smell is in potentiality; for the sensible object makes the sense active, so that it must necessarily exist in potentiality beforehand.
Ἡ δ’ ὀσμὴ καπνώδης τίς ἐστιν ἀναθυμίασις, ἡ δ’ ἀναθυμίασις ἡ καπνώδης ἐκ πυρός.
And odor is a kind of smoky exhalation, and smoky exhalation comes from fire.
§2.20Διὸ καὶ τῷ περὶ τὸν ἐγκέφαλον τόπῳ τὸ τῆς ὀσφρήσεως αἰσθητήριόν ἐστιν ἴδιον· δυνάμει γὰρ θερμὴ ἡ τοῦ ψυχροῦ ὕλη ἐστίν.
Therefore the sensory organ of smell is properly in the region of the brain; for the matter of the cold is potentially hot.
Καὶ ἡ τοῦ ὄμματος γένεσις τὸν αὐτὸν ἔχει τρόπον· ἀπὸ τοῦ ἐγκεφάλου γὰρ συνέστηκεν· οὗτος γὰρ ὑγρότατος καὶ ψυχρότατος τῶν ἐν τῷ σώματι μορίων ἐστίν.
And the generation of the eye is in the same way; for it is constituted from the brain; for this is the wettest and coldest of the parts in the body.
§2.21Τὸ δ’ ἁπτικὸν γῆς.
And the organ of touch is of earth.
Τὸ δὲ γευστικὸν εἶδός τι ἁφῆς ἐστίν.
And taste is a kind of touch.
Καὶ διὰ τοῦτο πρὸς τῇ καρδίᾳ τὸ αἰσθητήριον αὐτῶν, τῆς τε γεύσεως καὶ τῆς ἁφῆς· ἀντίκειται γὰρ τῷ ἐγκεφάλῳ αὕτη, καὶ ἔστι θερμότατον τῶν μορίων.
And because of this their sensory organ, both of taste and of touch, is near the heart; for this is opposite to the brain, and is the hottest of the parts.
Καὶ περὶ μὲν τῶν αἰσθητικῶν τοῦ σώματος μορίων ἔστω τοῦτον τὸν τρόπον διωρισμένα.
And concerning the sensory parts of the body, let them be defined in this way.