§2.1Τοῦ δὲ σώματος ἐν οἷς ἐγγίγνεσθαι πέφυκεν αἰσθητηρίοις, ἔνιοι μὲν ζητοῦσι κατὰ τὰ στοιχεῖα τῶν σωμάτων· οὐκ εὐποροῦντες δὲ πρὸς τέτταρα πέντ’ οὔσας συνάγειν, γλίχονται περὶ τῆς πέμπτης.
As for the sense-organs of the body in which the senses are by nature produced, some seek to explain them according to the elements of bodies; but being unable to connect them, which are five in number, with the four elements, they yearn for a fifth.
§2.2Ποιοῦσι δὲ πάντες τὴν ὄψιν πυρὸς διὰ τὸ πάθους τινὸς ἀγνοεῖν τὴν αἰτίαν· θλιβομένου γὰρ καὶ κινουμένου τοῦ ὀφθαλμοῦ φαίνεται πῦρ ἐκλάμπειν·
They all make sight consist of fire because they are ignorant of the cause of a certain affection; for when the eye is pressed and moved, fire seems to flash out.
τοῦτο δ’ ἐν τῷ σκότει πέφυκε συμβαίνειν, ἢ τῶν βλεφάρων ἐπικεκαλυμμένων· γίνεται γὰρ καὶ τότε σκότος.
This naturally occurs in the dark, or when the eyelids are closed, for then too darkness is produced.
Ἔχει δ’ ἀπορίαν τοῦτο καὶ ἑτέραν.
But this also presents another difficulty.
§2.3Εἰ γὰρ μὴ ἔστι λανθάνειν αἰσθανόμενον καὶ ὁρῶντα ὁρώμενόν τι, ἀνάγκη ἄρ’ αὐτὸν ἑαυτὸν ὁρᾶν τὸν ὀφθαλμόν.
For if it is impossible for one who perceives and sees to escape his own notice when seeing something seen, the eye must therefore see itself.
Διὰ τί οὖν ἠρεμοῦντι τοῦτ’ οὐ συμβαίνει;
Why then does this not happen when it is at rest?
§2.4Τὰ δ’ αἴτια τούτου, καὶ τῆς ἀπορίας καὶ τοῦ δοκεῖν πῦρ εἶναι τὴν ὄψιν, ἐντεῦθεν ληπτέον.
The causes of this, both of the difficulty and of the opinion that sight is fire, must be grasped from the following.
Τὰ γὰρ λεῖα πέφυκεν ἐν τῷ σκότει λάμπειν, οὐ μέντοι φῶς γε ποιεῖ, τοῦ δ’ ὀφθαλμοῦ τὸ καλούμενον μέλαν καὶ μέσον λεῖον φαίνεται.
Smooth things naturally shine in the dark, yet they do not produce light; and what is called the black and center of the eye appears smooth.
Φαίνεται δὲ τοῦτο κινουμένου τοῦ ὄμματος διὰ τὸ συμβαίνειν ὥσπερ δύο γίνεσθαι τὸ ἕν.
This shining appears when the eye is moved, because it happens that the one becomes, as it were, two.
Τοῦτο δ’ ἡ ταχυτὴς ποιεῖ τῆς κινήσεως, ὥστε δοκεῖν ἕτερον εἶναι τὸ ὁρῶν καὶ τὸ ὁρώμενον.
This is produced by the speed of the movement, so that the seeing part and the seen part appear to be different.
§2.5Διὸ καὶ οὐ γίνεται, ἂν μὴ ταχέως καὶ ἐν σκότει τοῦτο συμβῇ· τὸ γὰρ λεῖον ἐν τῷ σκότει πέφυκε λάμπειν, οἷον κεφαλαὶ ἰχθύων τινῶν καὶ ὁ τῆς σηπίας θολός·
Therefore, this does not happen unless it occurs quickly and in the dark; for smooth things naturally shine in the dark, such as the heads of certain fishes and the ink of the cuttlefish.
καὶ βραδέως μεταβάλλοντος τοῦ ὄμματος οὐ συμβαίνει ὥστε δοκεῖν ἅμα ἓν καὶ δύο εἶναι τό θ’ ὁρῶν καὶ τὸ ὁρώμενον.
And if the eye moves slowly, it does not happen that the seeing and the seen appear to be simultaneously one and two.
§2.6Ἐκείνως δ’ αὐτὸς αὑτὸν ὁρᾷ ὁ ὀφθαλμός, ὥσπερ καὶ ἐν τῇ ἀνακλάσει, ἐπεὶ εἴ γε πῦρ ἦν, καθάπερ Ἐμπεδοκλῆς φησὶ καὶ ἐν τῷ Τιμαίῳ γέγραπται, καὶ συνέβαινε τὸ ὁρᾶν ἐξιόντος ὥσπερ ἐκ λαμπτῆρος τοῦ φωτός, διὰ τί οὐ καὶ ἐν τῷ σκότει ἑώρα ἂν ἡ ὄψις;
In that way the eye sees itself, just as in reflection; since if it were indeed fire, as Empedocles says and as is written in the Timaeus, and if seeing occurred because light went out as if from a lantern, why would sight not have seen in the dark too?
§2.7Τὸ δ’ ἀποσβέννυσθαι φάναι ἐν τῷ σκότει ἐξιοῦσαν, ὥσπερ ὁ Τίμαιος λέγει, κενόν ἐστι παντελῶς· τίς γὰρ ἀπόσβεσις φωτός ἐστιν;
But to say that sight is extinguished in the dark as it goes out, as the Timaeus says, is completely empty; for what is the extinction of light?
Σβέννυται γὰρ ἢ ὑγρῷ ἢ ψυχρῷ τὸ θερμὸν καὶ ξηρόν, οἷον δοκεῖ τό τ’ ἐν τοῖς ἀνθρακώδεσιν εἶναι πῦρ καὶ ἡ φλόξ, ὧν τῷ φωτὶ οὐδέτερον φαίνεται ὑπάρχον.
For the hot and dry is extinguished by either the wet or the cold, as the fire in embers and flame seem to be, neither of which appears to belong to light.
§2.8Εἰ δ’ ἄρα ὑπάρχει μὲν ἀλλὰ διὰ τὸ ἠρέμα λανθάνει ἡμᾶς, ἔδει μεθ’ ἡμέραν τε καὶ ἐν τῷ ὕδατι ἀποσβέννυσθαι τὸ φῶς, καὶ ἐν τοῖς πάγοις μᾶλλον γίνεσθαι σκότον· ἡ γοῦν φλὸξ καὶ τὰ πεπυρωμένα σώματα πάσχει τοῦτο·
But if indeed they do belong to it, but escape our notice because of being slight, light ought to be extinguished by day and in water, and darkness ought to occur more in times of frost; at any rate, flame and ignited bodies undergo this.
νῦν δ’ οὐδὲν συμβαίνει τοιοῦτον.
But now nothing of the sort happens.
§2.9Ἐμπεδοκλῆς δ’ ἔοικε νομίζοντι ὁτὲ μὲν ἐξιόντος τοῦ φωτός, ὥσπερ εἴρηται πρότερον, βλέπειν· λέγει γοῦν οὕτως. Ὡς δ’ ὅτε τις πρόοδον νοέων ὡπλίσσατο λύχνον,
χειμερίην διὰ νύκτα πυρὸς σέλας αἰθομένοιο,
ἅψας παντοίων ἀνέμων λαμπτῆρας ἀμουργούς,
οἵτ’ ἀνέμων μὲν πνεῦμα διασκιδνᾶσιν ἀέντων,
φῶς δ’ ἔξω διαθρῶσκον, ὅσον ταναώτερον ἦεν,
λάμπεσκεν κατὰ βηλὸν ἀτειρέσιν ἀκτίνεσσιν· ὢς δὲ τότ’ ἐν μήνιγξιν ἐεργμένον ὠγύγιον πῦρ
λεπτῇσιν ὀθόνῃσι λοχάζετο κύκλοπα κούρην· αἱ δ’ ὕδατος μὲν βένθος ἀπέστεγον ἀμφινάοντος,
πῦρ δ’ ἔξω διαθρῶσκον, ὅσον ταναώτερον ἦεν. §2.10Ὁτε μὲν οὖν οὕτως ὁρᾶν φησίν, ὁτὲ δὲ ταῖς ἀπορροίαις ταῖς ἀπὸ τῶν ὁρωμένων.
Empedocles seems to think sometimes that we see because light goes out, as has been said before; at least he speaks thus: "As when someone, planning to go out, prepares a lantern, through a wintry night, a blaze of burning fire, fitting lantern-guards to ward off all kinds of winds, which scatter the breath of the blowing winds, while the light, leaping outside, as much of it as was finer, shone across the threshold with weariless rays; so then the primeval fire, enclosed in membranes, held the round pupil with fine linens, and these kept out the depth of the surrounding water, but the fire leaped outside, as much of it as was finer." Sometimes, then, he says we see in this way, and at other times by the emanations from the things seen.
Δημόκριτος δ’ ὅτι μὲν ὕδωρ εἶναί φησι, λέγει καλῶς, ὅτι δ’ οἴεται τὸ ὁρᾶν εἶναι τὴν ἔμφασιν, οὐ καλῶς· τοῦτο μὲν γὰρ συμβαίνει ὅτι τὸ ὄμμα λεῖον, καὶ ἔστιν οὐκ ἐν ἐκείνῳ ἀλλ’ ἐν τῷ ὁρῶντι· ἀνάκλασις γὰρ τὸ πάθος.
And Democritus, while he speaks well in saying that the eye is water, does not speak well in thinking that seeing is the reflection; for this happens because the eye is smooth, and it is not in that eye but in the one who sees; for the affection is reflection.