Humanitext Reader

Aristotle · On Sense and Sensibilia §6.12-6.22

Propagation of Light and Sensory Perception in a Medium

Passage 12 of 15 · Greek

Summary

Starting with Empedocles' view on the temporal propagation of light, the text discusses the influence of distance in sensory perception via a medium, the difference between transmission and alteration, and the distinction between numerically identical objects and qualitatively identical sensations.

§6.12Ἆρ’ οὖν οὕτω καὶ τὸ ὁρώμενον καὶ τὸ φῶς;
Is it then the same also with the object of sight and light?
Καθάπερ καὶ Ἐμπεδοκλῆς φησὶν ἀφικνεῖσθαι πρότερον τὸ ἀπὸ τοῦ ἡλίου φῶς εἰς τὸ μεταξὺ πρὶν πρὸς τὴν ὄψιν ἢ ἐπὶ τὴν γῆν.
Just as Empedocles too says that the light from the sun arrives first at the intermediate space before reaching the sight or the earth.
§6.13Δόξειε δ’ ἂν εὐλόγως τοῦτο συμβαίνειν· τὸ γὰρ κινούμενον κινεῖταί ποθέν ποι, ὥστ’ ἀνάγκη εἶναί τινα καὶ χρόνον ἐν ᾧ κινεῖται ἐκ θατέρου πρὸς θάτερον· ὁ δὲ χρόνος πᾶς διαιρετός, ὥστε ἦν ὅτε οὔπω ἑωρᾶτο ἀλλ’ ἔτ’ ἐφέρετο ἡ ἀκτὶς ἐν τῷ μεταξύ.
And this would seem to happen reasonably; for that which moves, moves from somewhere to somewhere, so that there must also be some time in which it moves from the one to the other; and all time is divisible, so that there was a time when it was not yet seen but the ray was still being carried in the intermediate space.
§6.14Καὶ εἰ ἅπαν ἅμα ἀκούει καὶ ἀκήκοε καὶ ὅλως αἰσθάνεται καὶ ᾔσθηται, καὶ μή ἐστι γένεσις αὐτῶν, ἀλλ’ εἰσὶν ἄνευ τοῦ γίνεσθαι ὅμως οὐδὲν ἧττον, ὥσπερ ὁ ψόφος ἤδη γεγενημένης τῆς πληγῆς οὔπω πρὸς τῇ ἀκοῇ.
And even if one simultaneously hears and has heard, and in general perceives and has perceived, and there is no generation of these, but they exist without coming to be, nevertheless, it is no less the case, just as sound, when the blow has already occurred, is not yet at the hearing.
§6.15Δηλοῖ δὲ τοῦτο καὶ ἡ τῶν γραμμάτων μετασχημάτισις, ὡς γιγνομένης τῆς φορᾶς ἐν τῷ μεταξύ· οὐ γὰρ τὸ λεχθὲν φαίνονται ἀκηκοότες διὰ τὸ μετασχηματίζεσθαι φερόμενον τὸν ἀέρα.
And this is also shown by the alteration of letters, on the ground that the transmission occurs in the medium; for they do not appear to have heard what was said, because the air in transmission is altered.
Ἆρ’ οὖν οὕτω καὶ τὸ χρῶμα καὶ τὸ φῶς;
Is it then the same also with color and light?
§6.16Οὐ γὰρ δὴ τῷ πῶς ἔχειν τὸ μὲν ὁρᾷ τὸ δ’ ὁρᾶται, ὥσπερ ἴσα ἐστίν· οὐθὲν γὰρ ἔδει που ἑκάτερον εἶναι· τοῖς γὰρ ἴσοις γινομένοις οὐδὲν διαφέρει ἢ ἐγγὺς ἢ πόρρω ἀλλήλων εἶναι.
For surely it is not by being in a certain state that the one sees and the other is seen, as is the case with equal things; for then there would be no need for each to be somewhere; for to things that are equal, it makes no difference whether they are near or far from each other.
§6.17Ἣ περὶ μὲν τὸν ψόφον καὶ τὴν ὀσμὴν τοῦτο συμβαίνειν εὔλογον· ὥσπερ γὰρ ὁ ἀὴρ καὶ τὸ ὕδωρ συνεχῆ μέν, ἀλλ’ ὅμως μεμέρισται ἀμφοτέρων ἡ κίνησις.
Or, while in the case of sound and odor, it is reasonable that this happens; for though air and water are continuous, yet the movement of both is divided.
Διὸ καὶ ἔστι μὲν ὡς τὸ αὐτὸ ἀκούει ὁ πρῶτος καὶ ὁ ὕστερος καὶ ὀσφραίνεται, ἔστι δ’ ὡς οὔ.
Therefore, there is a sense in which the first and the later person hear and smell the same thing, and a sense in which they do not.
§6.18Δοκεῖ δέ τισιν εἶναι ἀπορία καὶ περὶ τούτων· ἀδύνατον γάρ φασί τινες ἄλλον ἄλλῳ τὸ αὐτὸ ἀκούειν ἢ ὁρᾶν καὶ ὀσφραίνεσθαι· οὐ γὰρ οἷόν τ’ εἶναι πολλοὺς καὶ χωρὶς ὄντας ἀκούειν ἢ ὀσφραίνεσθαι· τὸ γὰρ ἓν χωρὶς ἂν αὐτὸ αὑτοῦ εἶναι.
But to some there seems to be a puzzle also about these things; for some say it is impossible for one person and another to hear or see or smell the same thing; for they say it is not possible for many who are separate to hear or smell [the same thing]; for otherwise the single thing would be separate from itself.
§6.19Ἢ τοῦ μὲν κινήσαντος πρῶτον, οἷον τῆς κώδωνος ἢ λιβανωτοῦ ἢ πυρός, τοῦ αὐτοῦ καὶ ἑνὸς ἀριθμῷ αἰσθάνονται πάντες, τοῦ δὲ δὴ ἰδίου ἑτέρου ἀριθμῷ, εἴδει δὲ τοῦ αὑτοῦ, διὸ ἅμα πολλοὶ ὁρῶσι καὶ ὀσμῶνται καὶ ἀκούουσιν.
Or is it that they all perceive the same and numerically one thing in the case of that which first initiated the movement, such as the bell, the frankincense, or the fire, but they perceive what is peculiar to each as numerically different, though the same in species, which is why many simultaneously see, smell, and hear?
Ἔστι δ’ οὔτε σώματα ταῦτα, ἀλλὰ πάθος καὶ κίνησίς τις (οὐ γὰρ ἂν τοῦτο συνέβαινεν), οὔτ’ ἄνευ σώματος.
And these are neither bodies, but rather a certain affection and movement (for otherwise this would not happen), nor yet are they without body.
§6.20Περὶ δὲ τοῦ φωτὸς ἄλλος λόγος· τῷ εἶναι γάρ τι φῶς ἐστίν, ἀλλ’ οὐ κίνησίς τις.
But about light, there is another account; for light exists by being something, and is not a certain movement.
Ὅλως δὲ οὐδὲ ὁμοίως ἐπί τε ἀλλοιώσεως ἔχει καὶ φορᾶς· αἱ μὲν γὰρ φοραὶ εὐλόγως εἰς τὸ μεταξὺ πρῶτον ἀφικνοῦνται (δοκεῖ δ’ ὁ ψόφος εἶναι φερομένου τινὸς κίνησις), ὅσα δ’ ἀλλοιοῦται, οὐκέτι ὁμοίως· ἐνδέχεται γὰρ ἀθρόον ἀλλοιοῦσθαι, καὶ μὴ τὸ ἥμισυ πρότερον, οἷον τὸ ὕδωρ ἅμα πᾶν πήγνυσθαι.
In general, it is not even similar in the case of alteration and of transmission; for transmissions reasonably arrive first at the medium (and sound seems to be a movement of something transmitted), but as for things that undergo alteration, it is no longer similar; for it is possible for a thing to be altered all at once, and not the half of it first, as water freezes all at once.
§6.21Οὐ μὴν ἀλλ’ ἂν ᾖ πολὺ τὸ θερμαινόμενον ἢ πηγνύμενον, τὸ ἐχόμενον ὑπὸ τοῦ ἐχομένου πάσχει, τὰ δὲ πρῶτον ὑπ’ αὐτοῦ τοῦ ἀλλοιοῦντος μεταβάλλει, καὶ οὐκ ἀνάγκη ἅμα ἀλλοιοῦσθαι καὶ ἀθρόον.
Nevertheless, if that which is heated or frozen is large, the adjacent part is affected by the adjacent part, while the first parts change under the influence of the altering agent itself, and it is not necessary that they be altered simultaneously and all at once.
§6.22Ἦν δ’ ἂν καὶ τὸ γεύεσθαι ὥσπερ ἡ ὀσμή, εἰ ἐν ὑγρῷ ἦμεν καὶ πορρωτέρω ἔτι πρὶν θιγεῖν αὐτοῦ ᾐσθανόμεθα.
And tasting would also be like smell, if we were in a liquid and perceived it from further away before touching it.
Εὐλόγως δ’ ὧν ἐστὶ μεταξὺ τοῦ αἰσθητηρίου, οὐχ ἅμα πάντα πάσχει, πλὴν ἐπὶ τοῦ φωτὸς διὰ τὸ εἰρημένον.
And it is reasonable that, in the case of those senses where there is something intermediate to the sense organ, not all parts are affected simultaneously, except in the case of light, for the reason stated.
Διὰ τὸ αὐτὸ δὲ καὶ ἐπὶ τοῦ ὁρᾶν· τὸ γὰρ φῶς ποιεῖ τὸ ὁρᾶν.
And for the same reason in the case of seeing; for light produces seeing.

Notes

  1. §6.14ἅπαν ἅμα ἀκούει καὶ ἀκήκοε — An expression highlighting the instantaneous nature of perception, where the present and perfect aspects coincide. In Aristotelian philosophy, while motion remains incomplete until its end, perception is an activity (energeia) in which the act of perceiving and having perceived (e.g., hearing and having heard) occur simultaneously.
  2. §6.16τῷ πῶς ἔχειν τὸ μὲν ὁρᾷ τὸ δ’ ὁρᾶται — Meaning "by being in a certain state (or relation)." It indicates that the relation between the perceiver and the perceived is not like an abstract relative relation (such as "equality") that is independent of spatial placement. If perception were such a relation, distance would not matter, but in reality, a mediating space is required.
  3. §6.19τοῦ μὲν κινήσαντος πρῶτον ... τοῦ δὲ δὴ ἰδίου — Distinguishes between the primary external source of motion (which is numerically one, "hen arithmôi") and the particular affection in the medium acting upon each individual's sense organ (which is numerically distinct but identical in species, "heteron arithmôi, eidei de to auto"). This logically explains how multiple separate people can simultaneously perceive the same source (such as a bell).
  4. §6.20τῷ εἶναι γάρ τι φῶς ἐστίν — Meaning "for light exists by being something (a state or presence)." In other works (such as De Anima II), Aristotle defines light as the actuality of the transparent rather than a spatial movement. He argues here that because light is a state (or presence) rather than a movement (transmission), it occurs without a time lapse.

Cite this passage

Aristotle, On Sense and Sensibilia §6.12-6.22. Humanitext Reader, https://reader.humanitext.ai/en/text/urn:cts:greekLit:tlg0086.tlg041.humanitext-grc1:6.12-6.22

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