The passage 153e-154a of the Theaetetus it is the beginning of a critique in which Plato seeks to refute relativism of both the Protagorean and Heraclitean types. Through Socrates, he observes to his interlocutor that if nothing exists in itself, it would be an intermediary state between the perceiver and the perceived object. At every moment, both one and the other would transform into something else, with no possibility of apprehension, attesting to the emptiness of the determination.
With this, Plato sees the need to postulate principles that guarantee the stability of beings, providing them with determination. Therefore, the hypothesis of Ideas that are close to the Parmenidian model is implicit and will be dealt with in other dialogues.
At the Parmenides, for example, the criticism made to the problem of the relationship of Ideas with the corresponding sentient beings is described. In an attempt to solve the contradiction that invades the discourse since it strives to think about reality, the theory of Ideas works as a purification. The Idea is a characteristic mark of the identity thought that imposes itself and that exists by itself as identity and on which knowledge of the objects that participate in it can be founded and providing stability to the
logos. Plato observes that, even in beings that change all the time (sensible), there is sufficient immobility to be able to of him having knowledge and that such immobility or stability does not derive from the sensitive, but from another type of reality, the intelligible.In order to think about concrete identities, the existence of ideal identities outside the contingency of every relationship: to say that there is a Greatness or Equality in itself is not to say another thing. Thus, the thought of identity allows itself to be led to the fact that, for him, the formulation of the principle of identity is not necessarily a simple tautology: the pure identity itself, which such a principle expresses, guides, on the contrary, the theory of reminiscence; on the occasion of sensitive interrelations, he remembers the Idea as a pure identity in itself, in a situation that, by itself, includes a real content.
The difficulties involved in the problem of participation begin with passage 130e-131c of the Parmenides where Socrates displays his understanding of Ideas. For him, things participate in Ideas that give it the possibility of denomination. But old Parmenides asks him if it is the whole Idea or only a part of it that participates in what it participates in, remaining one in each of the multiple beings. If so, then, the Eleatic objects, she would be separated from herself, which for Socrates is absurd.
Such criticism is pointed out by some researchers as being a revision that Plato himself makes of his theory, as well as an impulse for a new development in the subsequent dialogues. The characterization of the theory of ideas, in the first part of Parmenides, allows to recognize the positions placed by the great dialogues. The ontological dualism is evoked through the different status of what the Republic called a sensible place and an intelligible place, in relation to the principle of non-contradiction. When the sensible is the place of contradiction, where identity can show itself at the same time one and multiple, similar and dissimilar, the intelligible is, on the contrary, the place of non-contradiction. The identity thought that governs the logos it excludes the contradiction and the like itself could not be shown to be dissimilar.
How, then, to reconcile two orders of distinct realities? If the sensitive multiple participates in the Idea, does it remain one or do it divide into distinct parts? If she splits, she is no longer herself; if it remains one in each object, it is separate from itself.
Aristotle recalls that the term participation (methexes) is properly Platonic and that the Pythagoreans defined the existence of things by imitation (mimesis) of the names. These two terms are presented as two ways of representing the main presence, in the sensible, of an order of reality apprehended only by the soul. Sparing no criticism of his own theory, and concerned to eliminate in advance the false solutions, Plato considers precisely the two possibilities, characteristically opposing to them the same argument derived from an argument known under the name of “third men". The reasoning is as follows: if the Idea is just the common character of a sensitive multiplicity, perceived by an operation of the spirit, it is necessary to explain how the recognition of this character common, which brings together the Idea and the things that participate in it, do not depend, in turn, on some superior Idea, the only one capable of imposing this same character on everyone, and so on until the infinite. The argument works quite similarly if, in place of a methexes, the relationship between the sensible and the intelligible is considered as a mimesis: if Ideas are paradigms, models that exist from all eternity, and that things are simply images of them, copied, it will still be I need to explain how the Idea and the image-thing can be similar to each other and evoke for that some higher Idea that will fall under them criticism. Aristotle himself, in his Metaphysics, criticizes Plato for having conceived intelligible realities separate from sentient beings (ideal) and by determining that it is through participation that all things exist and that they are named according to their forms (eidesin).
In effect, the stagirite distinguishes between intelligible realities, called Ideas, and the forms that seem to be the true object of participation. In an article that seeks to map the occurrence of terms eidos and idea in Plato's dialogues, Jean-François Pradou analyzes the nuances that such a distinction can provoke in the interpretation of Plato's texts. According to Pradou, the term “Form” would refer to intrinsic or immanent characteristics of beings, which determined their qualities and would provide a certain resistance to becoming. This is what appears, with its figures, classes, aspects, etc. The term Idea, on the other hand, would be the intelligible and transcendent reality, reached only by thought, that bases the forms as a possibility of knowledge, being, therefore, the cause of beings sensitive.
Returning to the “third man” argument, which Plato considers to be true, one must show the distance between Plato and his disciple. There is no reason to differentiate senses from being when it is said, for example, that greatness is great. Aristotle would say the same word to be it refers to different meanings, and one cannot take statements as different as a simple predication and a definition of essence at the same level. But Plato, trusting the logos just as it is regulated by the norms of dialectical conversation, it never allows an opening on a reflection of the status of language that a theory of predication can constitute, and it refuses even more to consider any possibility of polysemy. One can take the analysis further and argue that, in Platonic terms, the “third man” argument is not an error, given the absurdity of the regression to infinity to where it shows that it leads to the contradiction of an identity thought out of the relationship, but that it is necessary to bring it into a relationship; the one of methexes, it just illustrates in its own way what the first hypothesis of the Parmenides will show, namely, the inconsistency of a strict identity thought that, by virtue of wanting to separate the object of the relationship, he even conceives it as pure limitlessness and, therefore, definitively, as ineffable. The absurdity of the infinite regress, which results in the limitlessness of an unspeakable and, therefore, non-existent identity, was very well conceived by Plato as an argument directed against the identity thinking that supported the theory of ideas; pleads, the opposite, the reestablishment of the relationship, even between the ideas themselves, because through it come the limitation and the possibility of saying an identity that, determined, is really identity as such.
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Participation seems indispensable to save our thinking from being. Without it, the theory of Ideas must face one last particularly dire argument. When one has, in fact, recognized the existence of two separate orders, in reality, the things of each order can only have power (dynamis) between things of the same order, and in no case over those of the other order. Moreover, as the two orders are distinct, not only the things of one cannot influence the things of the other, but, belonging to one order, one cannot know the realities of the other order; man cannot know divine things and God cannot know human things.
The first hypothesis of the Parmenides it presents itself, in fact, as a demonstration by the absurdity of the impossibility, for philosophy, of limiting itself to a strict thought of identity, either that is, to a thought that would believe to avoid contradiction by fleeing to identities that would put themselves and would be known by them same.
The principle of identity is, in fact, applied here to the point of absurdity, up to the limit that Antisthenes had set for it: a impossibility of a thing saying something other than itself, that is, in Aristotelian terms, the impossibility of predication. Antisthenes' reasoning was strictly based on the principle of identity. For him, the only kind of legitimate proposition corresponded to the schema: Socrates is Socrates. To say, for example, that Socrates is a man would be to say something other than himself. The one that Plato puts in the first hypothesis will be analyzed according to the same thought of identity taken to its limits. The only possible proposition is: the one is one. Every other form of attribution is perceived as contradictory. the one will be said unlimited, because there is the very form of indeterminacy. Outside of tautology, therefore, one speaks only negatively of the one.
A characteristic passage of the critique of the identity thought to which the first hypothesis corresponds is the one where it deals, precisely, with the identity in itself of the one. Diès sees there a kind of verbal magic trick by which Parmenides, having assumed that identity is not unity, would replace the a proposition that follows naturally (namely, to be identical is not to be one), by the other sophistry (namely, to be identical is not to be one). But, in fact, Plato relies simply on the fact that the one and the same differ, that is, that the same is other than the one: they are two distinct principles. Therefore, when the one is said to be the same, it becomes something else, the pair of the one and the same, and therefore is other than itself. Here the principle of identity is taken to the point of absurdity: nothing can be said of the other than himself. Thus, the impossibility placed is not limited, therefore, to the nature of the one in itself, but to the discourse. It is characteristic that Plato does not say that, by becoming identical with himself, the one would become two; he simply says that he would no longer be one with himself. This is the splitting of otherness itself and the real problem goes beyond the nature of the one: it is the problem of a discourse that, when putting an identity, says something about another, because it uses a name different. The identity of which one speaks seems, through the discourse, other than itself, by virtue of a contradiction that Plato illustrates by the opposition of the one and the multiple and which rests on the possibility of being able to enunciate several names concerning the same identity. The non-identity with oneself, which Plato affirms here from the one, could have deduced no matter what other identity than the one.
This first hypothesis thus leads to a total aporia: the one is not one and is not; it has no name, no definition, there can be no sensation, no opinion, no science. It is, therefore, the very type of thought by which one sought to apprehend it that is completely questioned again. Parmenides does not say that logos it follows that the one is not; he says, on the contrary, that it is impossible for the one to exist like this – intervention of a principle of reality that dominates the principle of identity and, moreover, constitutes a remarkable heresy, in the mouth of Parmenides, in relation to the parmenidism. Therefore, it is necessary to change the logos, which will only be done in the Sophist.
By João Francisco P. Cabral
Brazil School Collaborator
Graduated in Philosophy from the Federal University of Uberlândia - UFU
Master's student in Philosophy at the State University of Campinas - UNICAMP