As for the definition of a thing, this means that it has a unity which, however, closes around dis-unity. Two impressions which are met with separately are united in a proposition that identifies them. What is the essence of this all-important proposition? That the meaning of two phenomenon are identical. In Heidegger's lexicon, "A is A." The principle of identity, which presupposes but covers up an anterior difference, depends on the verb to-be. The identity of beings presupposes their difference; the difference between one being and another presupposes the fact that beings are. It turns out to be one and the same thing to say that the identity of any two beings presupposes their difference, and to say that any and all beings presuppose difference. For this later Heidegger, difference is another name for the sheer existence, the beingness, of all beings. Presupposed in the most elemental function of experience, this beingness is the ultimate horizon for all meaning. As a concept, it is also the placeholder for the claim that difference is anterior to identity. It would not be difficult to show how this thought, in all its radicality, is essentially alien to the modern epistemology of someone like Kant, where he installs unity above plurality among the categories of quantity. Nor would it be difficult to show that most thinkers presently called or calling themselves "postmodern" build on one or another variation of this idea.

There is more. Heidegger has said that the identity of "A with A" presupposes the proposition that it is so. In other words, acts of identification, of giving meaning, of saying "A is A," depend first on the fact that we who commit those acts have a relation to what it means to-be; because of that relation we can affirm that something is, for instance, a chair and not a table. This means that it is possible to affirm that A belongs together with A only through and because of the fact that being and thinking belong together. The belonging-together (Zusammengehören) of being and thought is the central theme of Heidegger's later work. It is a remarkable feature of his essay on "The Principle of Identity" that he dares to call this relation one of identity, and then submit it to the same conditions he has just discerned for the identity of a thing with itself. The identity of being and thinking entails, on one hand, that thinking gathers differences into identities around the word "is," and on the other hand that the word "is" never occurs in pure form but only in and through thinking. In this belonging-together of being and thinking, Heidegger discerns the ungrounded wellspring, or essence (Wesen) of all meaning. These are one and the same event (Ereignis): Being appears as beings (or: difference is manifest as identity) in and through thinking, and thinking is the act or process of being manifesting itself as beings.

¶ 12:29 PM