Exteriority-to-Self

Exteriority-to-self is Sartre's ontological characterization of motion: the mode of being in which a being is simultaneously itself and its own nothingness, such that it cannot be contained within the self-identity of being-in-itself. For Sartre, the in-itself is massively, inertly what it is — pure positivity, self-coincidence, the sheer facticity of "being what it is." Motion ruptures this closure. Because motion cannot be deduced analytically from the essence of the in-itself, it must be taken as a brute, contingent fact whose ontological significance is precisely that it names a form of being that has "left itself" without becoming something else — a being that is exterior to itself. The moving 'this' is therefore a "substantiated nothing": it carries the trace of its own negation as part of its structure, making its trajectory a genesis of space within time.

This exteriority can only be apprehended by the For-itself — consciousness, the nihilating nothingness — through temporal ekstasis: the ecstatic standing-out of the present toward the past and the future. The For-itself alone can synthesize the positions of a moving body into a unified trajectory precisely because it is itself constituted by a self-differential structure (it is never simply identical to itself). Motion is thus the in-itself's "borrowed" or induced version of what consciousness is by nature: a being that does not coincide with itself. Exteriority-to-self names this ontological borrowing — the momentary irruption of nothingness into the dense positivity of the real, legible only from the standpoint of a consciousness that is always already outside itself.

Within the source jean-paul-sartre-hazel-barnes-being-and-nothingness, exteriority-to-self is a regional, specialized concept that appears at the intersection of Sartre's ontology of the in-itself and his account of temporality and space. It functions as a specification of the broader Sartrean dialectic between being-in-itself (pure positivity, self-identity) and being-for-itself (nothingness, self-differentiation): motion is the one point at which the in-itself phenomenally exhibits something structurally analogous to the for-itself's ekstatic constitution, without thereby becoming consciousness. It is an extension of the concept of Consciousness insofar as exteriority-to-self is precisely what consciousness is essentially and what the in-itself can only be accidentally, under the contingent condition of motion.

When mapped against the cross-referenced Lacanian concepts, exteriority-to-self resonates most directly with Gap and Lack. Like the Lacanian gap (béance), exteriority-to-self names a structural opening within being — a point where a thing is not fully coincident with itself, where nothingness is introduced into positivity. Like Lack, it is not a contingent absence but a structural feature that conditions perception and apprehension. However, where Lacan's gap and lack are effects of the signifier — strictly introduced by the symbolic order ("nothing in the real is missing; a lack can only be introduced when there are signs and symbols") — Sartre's exteriority-to-self is a pre-symbolic, ontological condition arising from the contingency of motion in the real. It thus occupies an analogous structural position to Lacanian lack but from within a phenomenological ontology rather than a linguistic-structural one. The concept also touches Negation and the Real: exteriority-to-self is how negation — nothingness — appears embedded in a real being, making the trajectory of motion a "substantiated nothing" rather than a pure ideal absence.

Being and Nothingness: An Essay on Phenomenological OntologyJean-Paul Sartre · 1943 (page unknown)

Thus motion is the being of a being which is exterior to itself… The only metaphysical question which is posited on the occasion of motion is that of exteriority to self.

The phrase "exterior to itself" is theoretically loaded because it collapses the classical metaphysical opposition between self-identity and otherness: a being is declared to be its own outside, smuggling the structure of nothingness into the heart of the in-itself. The further claim that this is "the only metaphysical question" posited by motion elevates exteriority-to-self from a description of physical displacement to the fundamental ontological problem — making motion not a topic for physics but the site where being and nothingness most nakedly intersect.