Humanitext Reader

Epicurus · Letter to Herodotus §47-51

Motion of Images, Sensation, and the Truth of Perception

Passage 3 of 9 · Greek

Summary

Epicurus explains the extremely fine nature and near-light-speed movement of images (eidola), the process by which vision and thought arise from images reaching our senses, and argues that the criterion of truth and falsehood lies in the addition of opinion.

§47οὐ μὴν οὐδ’ ἅμα κατὰ τοὺς διὰ λόγου θεωρητοὺς χρόνους αὐτὸ τὸ φερόμενον σῶμα ἐπὶ τοὺς πλείους τόπους ἀφικνεῖται — ἀδιανόητον γὰρ —, καὶ τοῦτο συναφικνούμενον ἐν αἰσθητῷ χρόνῳ ὅθεν δήποθεν τοῦ ἀπείρου οὐκ ἐξ οὗ ἂν περιλάβωμεν τὴν φορὰν τόπου ἔσται ἀφιστάμενον·
Indeed, neither does the moving body itself arrive at several places at once in the times contemplatable by reason—for that is inconceivable—; and this body, arriving at the same time in a sensible time from wherever in the infinite, will not be starting its motion from the place from which we comprehend its course.
ἀντικοπῇ γὰρ ὅμοιον ἔσται, κἂν μέχρι τοσούτου τὸ τάχος τῆς φορᾶς μὴ ἀντικοπὲν καταλίπωμεν.
For it will be similar to an obstruction, even if we assume the speed of its transit up to this point to be unobstructed.
χρήσιμον δὴ καὶ τοῦτο κατασχεῖν τὸ στοιχεῖον.
It is useful, indeed, to hold fast to this element as well.
εἶθ’ ὅτι τὰ εἴδωλα ταῖς λεπτότησιν ἀνυπερβλήτοις κέχρηται, οὐθὲν ἀντιμαρτυρεῖ τῶν φαινομένων· ὅθεν καὶ τάχη ἀνυπέρβλητα ἔχει, πάντα πόρον σύμμετρον ἔχοντα πρὸς τὸ ἀπείροις αὐτῶν μηθὲν ἀντικόπτειν ἢ ὀλίγα ἀντικόπτειν, πολλαῖς δὲ καὶ ἀπείροις εὐθὺς ἀντικόπτειν τι.
Next, that the images possess unsurpassed fineness is in no way contradicted by the phenomena; hence they also have unsurpassed speeds, having every passage commensurate with the fact that nothing or very few things obstruct their infinite number, whereas many and infinite things immediately obstruct something of them.
§48πρός τε τούτοις, ὅτι ἡ γένεσις τῶν εἰδώλων ἅμα νοήματι συμβαίνει.
In addition to these, the generation of the images happens as fast as a thought.
καὶ γὰρ ῥεῦσις ἀπὸ τῶν σωμάτων τοῦ ἐπιπολῆς συνεχής, οὐκ ἐπίδηλος σημειώσει διὰ τὴν ἀνταναπλήρωσιν, σῴζουσα τὴν ἐπὶ τοῦ στερεμνίου θέσιν καὶ τάξιν τῶν ἀτόμων ἐπὶ πολὺν χρόνον, εἰ καὶ ἐνίοτε συγχεομένη ὑπάρχει, καὶ συστάσεις ἐν τῷ περιέχοντι ὀξεῖαι διὰ τὸ μὴ δεῖν κατὰ βάθος τὸ συμπλήρωμα γίνεσθαι, καὶ ἄλλοι δὲ τρόποι τινὲς γεννητικοὶ τῶν τοιούτων φύσεών εἰσιν.
For also a flow from the surface of bodies is continuous, not apparent by detection because of the counter-replenishment, preserving the position and order of the atoms on the solid body for a long time, even if it is sometimes confused; and rapid combinations occur in the surrounding space, because there is no need for the replenishment to take place in depth; and there are also some other ways productive of such natures.
οὐθὲν γὰρ τούτων ἀντιμαρτυρεῖ〈ται〉 ταῖς αἰσθήσεσιν, ἂν βλέπῃ τις, τίνα τρόπον τὰς ἐναργείας [ἵνα] καὶ τὰς συμπαθείας ἀπὸ τῶν ἔξωθεν πρὸς ἡμᾶς ἀνοίσει.
For none of these is contradicted by the sensations, if one observes in what way one will refer the clear visions and sympathies from outside to ourselves.
§49Δεῖ δὲ καὶ νομίζειν ἐπεισιόντος τινὸς ἀπὸ τῶν ἔξωθεν τὰς μορφὰς ὁρᾶν ἡμᾶς καὶ διανοεῖσθαι·
And we must believe that we see and think of shapes when something enters from outside.
οὐ γὰρ ἂν ἐναποσφραγίσαιτο τὰ ἔξω τὴν ἑαυτῶν φύσιν τοῦ τε χρώματος καὶ τῆς μορφῆς διὰ τοῦ ἀέρος τοῦ μεταξὺ ἡμῶν τε κἀκείνων, οὐδὲ διὰ τῶν ἀκτίνων ἢ ὧν δήποτε ῥευμάτων ἀφ’ ἡμῶν πρὸς ἐκεῖνα παραγινομένων, οὕτως ὡς τύπων τινῶν ἐπεισιόντων ἡμῖν ἀπὸ τῶν πραγμάτων ὁμοχρόων τε καὶ ὁμοιομόρφων κατὰ τὸ ἐναρμόττον μέγεθος εἰς τὴν ὄψιν ἢ τὴν διάνοιαν, ὠκέως ταῖς φοραῖς χρωμένων,
For the external things would not stamp their own nature of color and shape through the air between us and them, nor through the rays or any flow from us to them, as they do by certain outlines entering us from the objects, having the same color and shape, according to the size fitting into our sight or mind, and moving with swift transits.
§50εἶτα διὰ ταύτην τὴν αἰτίαν τοῦ ἑνὸς καὶ συνεχοῦς τὴν φαντασίαν ἀποδιδόντων καὶ τὴν συμπάθειαν ἀπὸ τοῦ ὑποκειμένου σῳζόντων κατὰ τὸν ἐκεῖθεν σύμμετρον ἐπερεισμὸν ἐκ τῆς κατὰ βάθος ἐν τῷ στερεμνίῳ τῶν ἀτόμων πάλσεως.
Then, for this reason, they present the appearance of a single and continuous thing, and preserve the sympathy from the underlying object according to the commensurate pressure from there, resulting from the vibration of the atoms in the depth of the solid body.
καὶ ἣν ἂν λάβωμεν φαντασίαν ἐπιβλητικῶς τῇ διανοίᾳ ἢ τοῖς αἰσθητηρίοις εἴτε μορφῆς εἴτε συμβεβηκότων, μορφή ἐστιν αὕτη τοῦ στερεμνίου, γινομένη κατὰ τὸ ἑξῆς πύκνωμα ἢ ἐγκατάλειμμα τοῦ εἰδώλου·
And whatever appearance we receive by direct application of the mind or the senses, whether of shape or of accidents, this is the shape of the solid body, arising from the successive condensation or the remainder of the image.
τὸ δὲ ψεῦδος καὶ τὸ διημαρτημένον ἐν τῷ προσδοξαζομένῳ ἀεί ἐστιν. (. . . ἐπιμαρτυρηθήσεσθαι ἢ μὴ ἀντιμαρτυρηθήσεσθαι, εἶτ’ οὐκ ἐπιμαρτυρουμένου 〈ἢ ἀντιμαρτυρουμένου〉 κατά τινα κίνησιν ἐν ἡμῖν αὐτοῖς συνημμένην τῇ φανταστικῇ ἐπιβολῇ, διάληψιν δὲ ἔχουσαν, καθ’ ἣν τὸ ψεῦδος γίνεται. ) §51ἥ τε γὰρ ὁμοιότης τῶν φαντασμῶν οἱονεὶ ἐν εἰκόνι λαμβανομένων ἢ καθ’ ὕπνους γινομένων ἢ κατ’ ἄλλας τινὰς ἐπιβολὰς τῆς διανοίας ἢ τῶν λοιπῶν κριτηρίων οὐκ ἄν ποτε ὑπῆρχε τοῖς οὖσί τε καὶ ἀληθέσι προσαγορευομένοις, εἰ μὴ ἦν τινα καὶ ταῦτα πρὸς ἃ βάλλομεν· τὸ δὲ διημαρτημένον οὐκ ἂν ὑπῆρχεν, εἰ μὴ ἐλαμβάνομεν καὶ ἄλλην τινὰ κίνησιν ἐν ἡμῖν αὐτοῖς συνημμένην μὲν 〈τῇ φανταστικῇ ἐπιβολῇ〉, διάληψιν δὲ ἔχουσαν·
But falsehood and error are always in the opinion that is added. (...to be attested or not to be counter-attested, and then, if it is not attested or is counter-attested, according to some motion in ourselves joined with the apprehensive application but having a distinction, according to which falsehood arises.) For the similarity of the images, whether received as in a picture or in dreams or by any other applications of the mind or of the other criteria, would never belong to those things which are called existing and true, if there were not certain things to which we direct ourselves; but error would not exist if we did not also receive some other motion in ourselves, joined indeed with the apprehensive application, but having a distinction.
κατὰ δὲ ταύτην [τὴν συνημμένην τῇ φανταστικῇ ἐπιβολῇ, διάληψιν δὲ ἔχουσαν], ἐὰν μὲν μὴ ἐπιμαρτυρηθῇ ἢ ἀντιμαρτυρηθῇ, τὸ ψεῦδος γίνεται· ἐὰν δὲ ἐπιμαρτυρηθῇ ἢ μὴ ἀντιμαρτυρηθῇ, τὸ ἀληθές.
And according to this motion, if it is not attested or is counter-attested, falsehood arises; but if it is attested or is not counter-attested, truth.

Notes

  1. 47καὶ τοῦτο συναφικνούμενον ἐν αἰσθητῷ χρόνῳ ὅθεν δήποθεν τοῦ ἀπείρου οὐκ ἐξ οὗ ἂν περιλάβωμεν τὴν φορὰν τόπου ἔσται ἀφιστάμενον — This passage presents a highly difficult construction. The subject `τοῦτο` goes with the periphrastic future predicate `ἔσται ἀφιστάμενον`. The present participle `συναφικνούμενον` agrees with `τοῦτο`, meaning 'arriving at the same time' in a sensible time (`ἐν αἰσθητῷ χρόνῳ`). Epicurus argues that even if this body arrives at its destination simultaneously from any arbitrary place in the infinite (`ὅθεν δήποθεν τοῦ ἀπείρου`), it will not have started its motion from the specific starting place where we began to comprehend its course (`οὐκ ἐξ οὗ ἂν περιλάβωμεν τὴν φορὰν τόπου`).
  2. 50καὶ ἣν ἂν λάβωμεν φαντασίαν ἐπιβλητικῶς τῇ διανοίᾳ ἢ τοῖς αἰσθητηρίοις — The antecedent `φαντασίαν` is attracted into the relative clause `ἣν ἂν λάβωμεν` (equivalent to `ἣν ἂν φαντασίαν λάβωμεν`). This serves as the subject clause for `μορφή ἐστιν αὕτη τοῦ στερεμνίου` ('this [appearance] is the shape of the solid body'). The adverb `ἐπιβλητικῶς` describes the mode of cognition involving 'direct/attentive application' (`ἐπιβολή`), which is a central epistemological term in Epicureanism.
  3. 51εἰ μὴ ἦν τινα καὶ ταῦτα πρὸς ἃ βάλλομεν — The verb `βάλλομεν` in the relative clause is used intransitively (or with a omitted reflexive pronoun), meaning the active mental or sensory 'applying/directing oneself' (`ἐπιβάλλειν`) in Epicurean epistemology. Therefore, `πρὸς ἃ βάλλομεν` means 'the things to which we direct our attention/senses.' It explains, following a past-unreal conditional clause, that without external objective realities corresponding to our sensory images, the very similarity of those images could not exist.

Cite this passage

Epicurus, Letter to Herodotus §47-51. Humanitext Reader, https://reader.humanitext.ai/en/text/urn:cts:greekLit:tlg0537.tlg010.humanitext-grc1:47-51

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