Plato’s Theaetetus is a dialogue, in which the leading question: “what is knowledge?” is posed by Socrates to Theaetetus. Knowledge, a translation of epistememe, has two meanings; it is a practical know-how, which “extends across all possible human activities,” from how to make a pair of shoes to how to conduct a war. It is also understood as seeing or idein. What unites both is their relationship to beings in their unhiddenness, their truth. Seeing is the seeing of beings in their presence, as what they show themselves for. Similarly know-how is disposal over beings in their presence, in their unhiddenness. This leads Heidegger to define knowledge as: “knowing-one’s-way-around in something as the possession of truth.” (120)
The first answer that Theaetetus offers in response to Socrates’ question: “what is knowledge?” is that knowledge is perception (aisthesis). Heidegger then asks how this answer is arrived at, what is it in perception that appears to link it to knowledge, understood as the “possession of truth,” and thus to being – an understanding of which “is already included in conceiving anything which one apprehends as an entity.”
For the Greeks the becoming perceived of something in perception is the same as phantasia. This is what a thing appears as, what it shows itself as, its appearance. Heidegger makes the point that appearance should not be understood as illusion, what something seems like. Even so it will be seen that seeming returns at the end of Heidegger’s account of the Theaetetus as a feature of hiddenness i.e. untruth.
Returning to phantasia as appearance: that which we perceive in a perception is there in a state of being perceived, which we take for what it presents itself as. Heidegger gives an example: “the moon itself that appears in the sky, that presents itself and is present; this is something that shows itself.” The moon shows itself as being present, which we take for what it shows itself as, the moon. Therefore aisthesis has a double meaning relating to the perceived in its perceivedness, and our perception in which perceivedness occurs.
Therefore Theaetetus’ thesis is that knowledge, as truth, is this perceivedness of what is seen. That which we perceive in a perception is there before us as something that shows itself as present, as “a kind of unhiddenness.” Perception, aisthesis, is equated with truth as unhiddenness, aletheia, because it “appears the most immediate mode of the unhiddenness of something…the most tangible truth.”
Yet it is still open to question that what becomes manifest in this relationship, between what shows itself and perception, is the unhiddenness of beings as aletheia. For this to be the case our “perceptual comportments,” seeing, hearing etc, through which we have a perception, must “have a relationship to beings as such.” To test whether or not this is the case Heidegger’s analysis focuses on the essence of perception itself, asking whether or not a perceptual comportment “can bring itself into a relationship to beings as beings, such that the unhiddenness of beings is given in the perceivedness occurring in such a comportment.” (121)
Socrates begins his enquiry into the essence of perception by asking about the role of the senses, and by extension the body. It would appear that perception is the relation between what is immediately perceivable: smells, colours, sounds etc, and that which is able to take up a perceiving relationship with them. For smells that is the nose, for colour the eyes, etc. Does this mean that it is the body, through the senses, which has a perceptual relationship with what appears? Or is perception only achieved in passing through them, i.e. are the senses just a passageway to perception?
The second characterisation is agreed upon, with Socrates providing the proof: If perceiving was dispersed to different points on the body, so that the eyes are that which see, the ears that which hear etc, what we see and hear, colour and sound, would also be distributed to the corresponding points on the body. This would mean in order to see we would have to direct ourselves to our eyes, in order to hear we would have to direct ourselves to our ears. The end result would be that we could not hear and see something simultaneously.
This is an impossible state of affairs, therefore its opposite is acknowledged, every perception, rather than being dispersed to various points on the body, converges in a unity. This is not a bodily unity, for the body upholds the dispersion of perceiving through its organs of perception. Instead this unity is the “single sighted nature” that we possess, in which all sensory perceptions converge “in something like an idea” [i.e. knowledge, truth]. The idea is what is sighted, it is both seeing and what is seen in its presence, i.e. it is the thing’s essence that is immediately present before us. (126)
Our perceptions of objects in their perceivedness converge in a unity. When we see or hear we are not aware of our ears or eyes, “we do not see colour in our eyes, and we do not hear sounds in our ears…we see the colour on the book cover, we hear the sound of the door that someone slams.” (126) All these perceivable objects in their variety, converge in a “single sighted nature,” within “one region of the perceivable surroundings.” (127)
This single region of perceivability is there waiting to take in the plethora of perceptions that we have constantly to deal with. It does not originate from what we see, hear etc. Instead It is already there, waiting upon what converges in it, that which we constantly encounter in perception.
We have a sighted nature which holds up this region of perceivability, and which Plato calls soul. The soul is as one with this region itself: “This self-maintaining region which surrounds us belongs to ourselves, and is thereby a constant sameness;” it is “something in itself that is in or by ourselves.” (Plato) Therefore the soul is that which perceives, in the sense of “taking up the perceiving relationship to the perceivable.” This leads Plato to define the soul as that “which allows us to perceive all the objects of perception through the senses as instruments.”
As we saw in the previous post our sense organs do not take up a relationship to the perceivable – yet every perception; hearing, sight, has a bodily character. Perceptions are dispersed through the relevant sensory passageways; hearing is only accessible via the ears, colour through the eyes, each isolated in itself. Yet we see a colour and hear a sound at the same time. (130) This means both acts of seeing and hearing occur at the same point of time, but also that we perceive sound and colour together, “one is given along with the other.”
The question then concerns the statement: “we perceive sound and colour together.” If I say “I hear the sound” or “see the colour” it is clear which sense organ is active. In saying “sound and colour are perceived together” the question then has to be asked, through which sense organ do we perceive the “and” and the “together” of this proposition? The former implies plurality, while the latter implies unity, neither of which can be seen, heard or tasted.
The first step towards answering “what organ is in play when we perceive something in respect of both colour and sound?” is to show what is perceived in the situation in which we hear and see at the same time. To enable this Heidegger asks us to place ourselves in the imaginary situation of lying in a meadow, from which we can “see the blue of the sky, while simultaneously we hear the singing of the lark.” Asking how we perceive both together, the answer; we first of all perceive both as existing, i.e. as being, then that they are different from each other, “colour is one being, sound the other,” both the same as themselves, which also makes them countable. All that is thus perceived: “being, being one, different, both, the same, two, one, identity and non-identity,” is in addition to the colour and the sound, and are there as what Heidegger calls “an irremovable excess.” (135)
The identification of the excess, that which is there in addition to what is seen, heard etc. leads to the understanding that it is something that all our sensory perceptions, colours, sounds, tastes, touch have in common. Socrates then repeats his question: “with what sense-organs do you perceive this common element?” (138) This is asked because it has been shown that everything perceivable is perceived through a bodily organ. The excess, that which we perceive over and above what we see, hear etc, is common to all things, yet there is not a recognisable passageway to it, but there must be.
Dianoiein – inner perception
Theaetetus answers this question saying there is no special organ for perceiving the excess, the soul itself views the excess, while the sense organs give the soul access to colour, sound etc. Therefore the intrinsic duality of things, their physical properties and their being, are combined and seen in a unity by the soul, but which also has the capacity to separate them. This seeing of the excess by the soul is called dianoiein and is defined as the capacity “to look at a thing, thereby perceiving something about it,” a kind of inner perception. This seeing of the excess in dianoiein is “perceived so self-evidently and immediately that at first we do not pay the least attention to it.” (136)
As we have seen being belongs to everything perceivable, it is what all perceptions have in common; the question now is, where is it perceived? Is being in the perceivedness of the object or does it belong in some way to the soul? Theaetetus’ answer to this question also gives the characteristic of how the excess is engaged with: “In my view, ousia [being] belongs to what the soul, through and by itself strives for.” (146) The soul has a direct relationship to the excess, which is one of striving.
This striving is the fundamental characteristic of the soul’s relationship to being, and implies an active reaching for something. This contrasts with perception, which Heidegger defines as something we lose ourselves in, in perceiving we accept and have beings. (148) Striving, by definition, does not have the object it strives for, as an activity it is essentially incomplete, never-ending; if we achieve the object of our striving then it comes to an end.
Our immediate perception of beings, things, is non-regarding and non-conceptual. We do not occupy ourselves with beings as such, i.e. their being-blue or being-audible, nor do we grasp their being conceptually, i.e. their being-different, one etc. From this it is clear that in a perception we have beings before us, but not being, the excess. Our connection to being is instead one of striving by the soul, which carries us along, in a relationship which is also called eros.