§2#1Τί δ’ ἐστὶ τὸ ἐνύπνιον καὶ πῶς γίνεται, ἐκ τῶν περὶ τὸν ὕπνον συμβαινόντων μάλιστ’ ἂν θεωρήσαιμεν.
What the dream is and how it occurs we can best investigate from the circumstances of sleep.
Τὰ γὰρ αἰσθητὰ καθ’ ἕκαστον αἰσθητήριον ἡμῖν ἐμποιοῦσιν αἴσθησιν, καὶ τὸ γινόμενον ὑπ’ αὐτῶν πάθος οὐ μόνον ἐνυπάρχει ἐν τοῖς αἰσθητηρίοις ἐνεργουσῶν τῶν αἰσθήσεων, ἀλλὰ καὶ ἀπελθουσῶν.
For the objects of sensation produce sensation in us in each of the sense organs, and the affection produced by them remains in the sense organs not only while the sensations are active, but also after they have departed.
Παραπλήσιον γὰρ τὸ πάθος ἐπί τε τούτων καὶ ἐπὶ τῶν φερομένων ἔοικεν εἶναι.
For the affection in these cases seems to be similar to that of moving objects.
Καὶ γὰρ ἐπὶ τῶν φερομένων τοῦ κινήσαντος οὐκέτι θιγγάνοντος κινεῖται· τὸ γὰρ κινῆσαν ἐκίνησεν ἀέρα τινά, καὶ πάλιν οὗτος κινούμενος ἕτερον.
For in the case of moving objects, the motion continues even when the mover is no longer touching them; for the mover moved a certain portion of air, and this in turn, being moved, moves another.
Καὶ τοῦτον δὴ τὸν τρόπον, ἕως ἂν στῇ, ποιεῖται τὴν κίνησιν καὶ ἐν ἀέρι καὶ ἐν τοῖς ὑγροῖς.
And in this manner, indeed, until it stops, the motion is produced both in the air and in liquids.
Ὁμοίως δ’ ὑπολαβεῖν τοῦτο δεῖ καὶ ἐπ’ ἀλλοιώσεως· τὸ γὰρ θερμανθὲν ὑπὸ τοῦ θερμοῦ τὸ πλησίον θερμαίνει, καὶ τοῦτο διαδίδωσιν ἕως τῆς ἀρχῆς.
And we must assume this likewise in the case of qualitative change; for that which has been heated by a hot object heats what is near it, and this transmits it until it reaches the source.
Ὥστε καὶ ἐν ᾧ τὸ αἰσθάνεσθαι, ἐπειδή ἐστιν ἀλλοίωσίς τις ἡ κατ’ ἐνέργειαν αἴσθησις, ἀνάγκη τοῦτο συμβαίνειν.
Thus, even in that in which sensing resides, since sensation in actual exercise is a certain qualitative change, this must of necessity occur.
Διὸ τὸ πάθος ἐστὶν οὐ μόνον ἐν αἰσθανομένοις τοῖς αἰσθητηρίοις, ἀλλὰ καὶ ἐν πεπαυμένοις, καὶ ἐν βάθει καὶ ἐπιπολῆς.
Therefore, the affection exists not only in the sense organs while they are sensing, but also when they have ceased, both in the depth and on the surface.
Φανερὸν δ’ ὅταν συνεχῶς αἰσθανώμεθά μεθά τι· μεταφερόντων γὰρ τὴν αἴσθησιν ἀκολουθεῖ τὸ πάθος, οἶον ἐκ τοῦ ἡλίου εἰς τὸ σκότος· συμβαίνει γὰρ μηδὲν ὁρᾶν διὰ τὴν ἔτι ὑποῦσαν κίνησιν ἐν τοῖς ὄμμασιν ὑπὸ τοῦ φωτός.
This is clear when we sense something continuously; for when we transfer our sensation, the affection follows, as from the sun into darkness; for it happens that we see nothing because of the motion still remaining in the eyes from the light.
Κἂν πρὸς ἓν χρῶμα πολὺν χρόνον βλέψωμεν ἢ λευκὸν ἢ χλωρόν, τοιοῦτον φαίνεται ἐφ’ ὅπερ ἂν τὴν ὄψιν μεταβάλωμεν.
And if we look at one color for a long time, whether white or yellow-green, whatever we turn our sight to appears of that color.
Κἂν πρὸς τὸν ἥλιον βλέψαντες ἢ ἄλλο τι λαμπρὸν μύσωμεν, παρατηρήσασι φαίνεται κατ’ εὐθυωρίαν, ᾗ συμβαίνει τὴν ὄψιν ὁρᾶν, πρῶτον μὲν τοιοῦτον τὴν χρόαν, εἶτα μεταβάλλει εἰς φοινικοῦν κἄπειτα πορφυροῦν, ἕως ἂν εἰς τὴν μέλαιναν ἔλθῃ χρόαν καὶ ἀφανισθῇ.
And if, after looking at the sun or some other bright object, we close our eyes, it appears to those who observe closely, in a straight line where it happens that the sight sees, first of such a color, and then it changes to crimson and then to purple, until it comes to the black color and disappears.
Καὶ αἱ ἀπὸ τῶν κινουμένων δὲ μεταβάλλουσιν, οἷον ἀπὸ τῶν ποταμῶν, μάλιστα δ’ ἀπὸ τῶν τάχιστα ῥεόντων· φαίνεται γὰρ τὰ ἠρεμοῦντα κινούμενα.
And those movements from moving objects also change, as from rivers, especially from those flowing most rapidly; for stationary things appear to be moving.
Γίνονται δὲ καὶ ἀπὸ τῶν μεγάλων ψόφων δύσκωφοι καὶ ἀπὸ τῶν ἰσχυρῶν ὀσμῶν δύσοσμοι, καὶ ἐπὶ τῶν ὁμοίων.
People also become hard of hearing from great noises, and hard of smelling from strong odors, and likewise in similar cases.
Ταῦτά γε δὴ φανερῶς συμβαίνει τοῦτον τὸν τρόπον.
These things indeed clearly occur in this manner.
Ὅτι δὲ ταχὺ τὰ αἰσθητήρια καὶ μικρᾶς διαφορᾶς αἰσθάνεται, σημεῖον τὸ ἐπὶ τῶν ἐνόπτρων γινόμενον· περὶ οὗ καὶ αὐτοῦ ἐπιστήσας σκέψαιτό τις ἂν καὶ ἀπορήσειεν.
And that the sense organs sense quickly and even a small difference, is signaled by what occurs in mirrors; about which one might also reflect and be puzzled after paying attention to it.
Ἅμα δ’ ἐξ αὐτοῦ δῆλον ὅτι ὥσπερ καὶ ἡ ὄψις πάσχει, οὕτω καὶ ποιεῖ τι.
At the same time, from this itself it is clear that just as sight experiences something, so also it produces something.
Ἐν γὰρ τοῖς ἐνόπτροις τοῖς σφόδρα καθαροῖς, ὅταν τῶν καταμηνίων ταῖς γυναιξὶ γινομένων ἐμβλέψωσιν εἰς τὸ κάτοπτρον, γίνεται τὸ ἐπιπολῆς τοῦ ἐνόπτρου οἷον νεφέλη αἱματώδης· κἂν μὲν καινὸν ᾖ τὸ κάτοπτρον, οὐ ῥᾴδιον ἐκμάξαι τὴν τοιαύτην κηλῖδα, ἐὰν δὲ παλαιόν, ῥᾷον.
For in very clean mirrors, when women look into the mirror during their menstruation, the surface of the mirror becomes like a bloody cloud; and if the mirror is new, it is not easy to wipe off such a stain, but if it is old, it is easier.
Αἴτιον δ’, ὥσ περ εἴπομεν, ὅτι οὐ μόνον πάσχει τι ἡ ὄψις ὑπὸ τοῦ ἀέρος, ἀλλὰ καὶ ποιεῖ τι καὶ κινεῖ, ὥσπερ καὶ τὰ λαμπρά· καὶ γὰρ ἡ ὄψις τῶν λαμπρῶν καὶ ἐχόντων χρῶμα.
The cause, as we said, is that sight not only experiences something from the air, but also produces something and moves it, just as bright things do; for sight belongs to the class of things that are bright and have color.
Τὰ μὲν οὖν ὄμματα εὐλόγως, ὅταν ᾖ τὰ καταμήνια, διάκειται, ὥσπερ καὶ ἕτερον μέρος ὁτιοῦν· καὶ γὰρ φύσει τυγχάνουσι φλεβώδεις ὄντες.
It is reasonable, then, that the eyes are affected when menstruation occurs, just as any other part; for they happen to be naturally full of veins.
Διὸ γινομένων τῶν καταμηνίων διὰ ταραχὴν καὶ φλεγμασίαν αἱματικὴν ἡμῖν μὲν ἡ ἐν τοῖς ὄμμασι διαφορὰ ἄδηλος, ἔνεστι δέ (ἡ γὰρ αὐτὴ φύσις σπέρματος καὶ καταμηνίων), ὁ δ’ ἀὴρ κινεῖται ὑπ’ αὐτῶν, καὶ τὸν ἐπὶ τῶν κατόπτρων ἀέρα συνεχῆ ὄντα ποιόν τινα ποιεῖ καὶ τοιοῦτον οἷον αὐτὸς πάσχει· ὁ δὲ τοῦ κατόπτρου τὴν ἐπιφάνειαν.
Therefore, when menstruation occurs, because of disturbance and bloody congestion, the difference in the eyes is unclear to us, but it is present (for the nature of semen and of menstrual fluid is the same), and the air is moved by them, and makes the air upon the mirrors (which is continuous) of a certain quality, even such as it itself experiences; and this air in turn makes the surface of the mirror.