There are things that one just doesn’t think about. Things that are too fundamental, common sense, or oblique to warrant inquiry. For example, a phenomenon as vague and omnipresent as “change.” An earnest individual might come up to you and start throwing thought experiments at you. Suppose you don’t extract yourself from the situation. Suppose they start talking about the philosophical problem of a ship that, over time, has had all of its parts replaced in the course of renovations and repairs. Is it still the same ship? They want to know. They think that they are clever because there isn’t a yes or no answer. It’s the same ship, but it isn’t, but it is. The ship is the same but different. Almost mind blowing, raising problems of identity and continuity from the angle of a rational/empirical search for discrete units. Looking at only Symbolic entities, “ship,” “piece of ship,” etc, and logically connected Symbolic actions, “replacement of piece of ship,” etc, it is a cartoon problem with a cartoon solution.

In order to account for weird things like identity and continuity Aristotle developed a tri-part structure, the primal triad, consisting of the two poles of an opposing relation, and a material substratum shared between them (This is in Book 1 of Aristotle’s Natural Science). So in the case of the ship, the problem of continuity is solved. In the thought experiment, there is ship and not-the-same ship and they are set up as opposing each other. The ship can become not-the-same ship because of an underlying material that is constant, the wood or what have you. It is possible for a thing to change form because its material remains constant. So for Aristotle continuity can be established without reference to something like an in-between ship, a purely Symbolic placeholder.

However, this doesn’t directly address the problem of if the ship is actually different after all its replacements. Does the ship really have two different identities, and how does it move between identities? Enter Hegel. Hegel also developed a tri-part structure, a movement from thesis to anti-thesis to synthesis that is supposed to account for the self-becoming of scientific truth and knowledge. The process works by way of sublation, the thesis is sublated by the anti-thesis. The thesis is absorbed and mutated, but not forgotten, by the anti-thesis. It is precisely this development, and the recognition of the development, that Hegel regards as the synthesized truth (This is in Hegel’s Preface to the Phenomenology of Spirit). This is why historical consciousness is so key for Hegel, the past is revealed in the present and the present will be revealed in the future; delayed cognition. As Zizek notes, the synthesis is really the thesis as seen through the lens of the anti-thesis.

So the identity of the ship is a synthesis. It is neither the ship (thesis), nor the not-the-same ship (anti-thesis), but the ship that has become a different ship. The Hegelian view is the precursor to existentialism, and finds identity in its becoming. A thing’s identity is not static but contains both what the thing has been and what it will be, the historical perspective. And now we have what Zizek calls a dialectical materialism, an account of how matter and concrete events give rise to phenomenon like zeitgeist and arête, where a group of people becomes “a people” or a subject “becomes what they are.” The ship that could and did.

Dialectical materialism brings to the fore the dimension of the Real. This is Merleau-Ponty’ notion of the <i>tertium quid</i>, the “third thing” in relation to a purely rationalistic perspective, wherein truth is a mathematically deduced eternal axiom, and a purely empirical perspective, wherein truth is an inductive agglomeration of data. The tertium quid for Merleau-Ponty is the body, the source of lived experience and interactive muscle memory. The body is inherently a medium between self and world, and it demonstrates the intersection between self and world qua embodied and historical process. This dispels New Age notions of Astral Travel and ill-defined “consciousness,” as well as Technofuturist notions of memory implants and hyper-advanced AI. If for Foucault the soul is the prison of the body, for Merleau-Ponty the soul is the essence of the body. There is some ‘kernel’ some traumatic Thing, that subjectivity both lives and cannot grasp. We live through it but cannot catch it, this <i>tertium quid.</i>