Plato also helps us to understand how the imagination is built upon the Opposed. The Idea does not only determine that the concept needs to be an identity, it also determines what identity is assigned to a concept. How so? The perfection of the Idea implies that it is determined both absolutely and completely: it is entirely this and absolutely not that. As such, the Idea introduces absolute distinctions or oppositions onto which the concept can be modeled. Concepts are determined on the basis of the oppositions offered by the Ideas.
The ideal world not only functions as a model for the determination of concepts, it is also a model for judging the truth of statements. A statement, or a proposition expressing a specific relation between concepts, is true only if it is analogous to the relations that exist at the ideal level. According to Plato, while true statements are copies that maintain an internal resemblance to the Ideas, simulacra entertain only an external, secondary resemblance to the Idea. Hence, Plato does not argue for leaving the world of copies and representations altogether, but for separating true representations from false ones, the copies from the simulacra (DR, 333–34). As such, every judgment presupposes a subordination of difference to the analogous, to that which is proven to be similar to the Idea.
Finally, the same principle of identity is also active in perception. In order to attribute one concept to what is similar among different objects, these objects need to be perceived as being similar. This similarity, in turn, presupposes a correspondence between the qualities of the different senses. In sum, in representational thought, all the facets of thought—perception, the creation of concepts, the determination of concepts, and the judgment of statements—are fundamentally oriented by the quest of identity, by trying to detect what is the same or what is similar. This implies that everything that cannot be captured in an identity, everything that disrupts the similarity or multiplies the oppositions, cannot be thought and is not considered worth thinking. Representational thought, we might say, cannot think, as Carroll does, by playing differences off against one another. It can think difference only as difference under a higher identity.
I already mentioned that the postulates concern the presuppositions that representational thought makes about itself. It presupposes that it has a natural affinity with the true (first postulate) and a natural disposition to think in identities (fourth postulate). They share the conviction that the affinity and the disposition are natural. This, of course, is already implied in the fact that these are presuppositions, for presuppositions always indicate that something is regarded as natural and evident, and hence not in need of explanation. Still, what is characteristic of representational thought is not so much its specific presuppositions, but its presuppositional nature as such, the fact that it cannot make a true beginning (DR, 164). This is what Deleuze (DR, 167) means when he says that representational thought is built upon an Image of thought. It is also the reason why the third postulate, that of recognition, is considered to be central to representational thought (together with the second and fourth postulates) (DR, 188). The claim that thought is recognition means that when you are thinking, you are confronted with something you already have an inkling about. Plato’s philosophy of reminiscence is a good example: Plato believes that thought is a matter of remembering the knowledge we had before we were born. Thus, the object of recognitional thought is never exterior to thought. It is already part of thought. It is already presupposed in the definition of thought, and thus makes a true, new beginning of thought impossible. Deleuze pits the idea of thought as encounter against this conception of thought as recognition. According to Deleuze, thought is the activity not of discovering already existing entities, but of creating sense. Thought is a producing machine. Sense does not precede thought; it comes to existence only through the relationship between thought and the sign. And thought does not precede itself, either: it is prompted by the encounter with a sign.
Thinking Thought as a Discordant Play among the Different Faculties (Second Postulate)
It is clear that the postulate of recognition is characterized by the same primacy of unity and identity that we find in the fourth postulate: things can be recognized only if they bear some resemblance to what one already knows. Moreover, something can be recognized as being this particular thing only if one presupposes that this particular thing has remained the same over time and across the different faculties. Thus, one must presuppose the harmonious collaboration of the different faculties: their qualities need to be translatable into one another and combinable into a stable and uniform concept. There is, in other words, a subjective principle that corresponds to the identity of the object and the concept, namely, that of the common sense as concordia facultatum (sens commun). That is Deleuze’s second postulate of representational thought. Deleuze describes the common sense as “an organ, a function, a faculty of identification that brings diversity in general to bear upon the form of the Same. Common sense identifies and recognizes” (LS, 89). In its turn, the concordance of the qualities and the faculties presupposes that the thinking subject, of which the different faculties are modi, forms a unity. For the faculties to complement one another, they must be connected in one way or another. The Self is the link between the different faculties; they all set out from me. Ultimately, “it is the identity of the Self” that “grounds the harmony of all the faculties and their agreement on the form of a supposed Same object” (DR, 169).
The harmony of the faculties not only presupposes a common sense as concordia facultatum but also a good sense (bon sens). The latter determines the direction according to which the faculties function. Our thoughts, for example, are causally directed (the origin always precedes the effect); temporally directed (the future turns into the present, which in turn slips into the past); and synthetically directed (from the least to the most differentiated) (LS, 88). However, the good sense is always a “unique sense” (LS, 87); our thoughts can neither move in a different direction nor move in different directions at the same time. The directional character of good sense translates into a division of labor for the different faculties: “Good sense determines the contribution of the faculties in each case” (DR, 169). Good sense ensures that each faculty concentrates on its own object: eyes focus on the visible qualities, memory on the perceived qualities, and so on. When the faculties do not respect this division of labor, an error (erreur) arises. Errors are due to a shortcoming on the part of the good sense.
Since Deleuze considers sense to be absolute difference, common sense and good sense are of no use for thinking thought. In thinking thought, there is no harmonious collaboration of the different faculties grounded on the presupposition that it is the same object that can be sensed, recalled, conceived, and so on. Rather than a concordance of the different faculties, there is a discord. Rather than one object toward which the different faculties are oriented, each faculty has its own object. How so? Deleuze (DR, 182) claims that in the encounter with a sign, the sign is first sensed: thinking thought begins with sensibility. As shown above, what is sensed is not an identity that can be recognized. Because empiricism can deal with only positive identities, Deleuze introduces the following twist: what is sensed cannot be sensed empirically. As will be explained in more detail in chapter 3, this empirical insensibility, however, is also “what gives to be sensed,” what “defines the proper limits of sensibility” (DR, 290). It is not “a sensible being but the being of the sensible. It is not the given but that by which the given is given” (DR, 176). Empirical insensibility, in other words, is also what makes sensibility possible. It is what Deleuze calls “a sentiendum.” Because of its conditioning nature, the sentiendum is what must be sensed and what can only be sensed. In the presence of the sentiendum, sensibility confronts “its own limit and raises itself to the level of the transcendental exercise,” to what