'In Hegel's phenomenology of spirit, the I first emerges when the desiring subject seeks satisfaction by engaging in a struggle for recognition. The desire that initiates and sustains the development of the subject is not satisfied until the I "is at home with itself in its being other."
Lacan attempts to demonstrate the impossibility of transparent self-consciousness by turning Hegel's argument against itself. In his well-known essay, "The Mirror Stage as Formative of the Function of the I as Revealed in Psychoanalytic Experience," Lacan uses Hegel's analysis of the reflective/reflexive relation of self and other in the struggle for recognition to demonstrate that the I, understood as a perduring integrated ego, is a "specular image" that the infant first encounters in the gaze of other subjects....Contrary to Hegel's claim that the I is fully realized (and thus desire satisfied) in complete self-consciousness, Lacan contends that the subject is (always [italics]) incomplete and desire (never [it.]) satisfied. The impossibility of complete self-consciousness implies that "I think where I am not" or, conversely, that I am not where I think. "The formation of the I aw we experience it in psychoanalysis," Lacan argues, "is an experience that leads us to oppose any philosophy directly issuing from the Cogito."
Since desire cannot be satisfied, the wound that Hegel tries to heal remains open. The subject, in other words, is inevitably "split." This fissure is not secondary or consequent to a more primary or original unity or integrity. To the contrary, the subject is always already split. This split opens the "empty" space and "vacant" time of desire...."The radical heteronomy that Freud's discovery shows gaping within man can never again be covered over without whatever is used to hide it being profoundly dishonest." In terms approaching religious testimony, Lacan explains:
Kern unseres Wesen, the nucleus of our being, but it is not so much that Freud commands us to seek it as so many others before him have with the empty adage, 'Know thyself' --as to reconsider the ways that lead to it, and which he show us. Or rather that which he proposes for us to attain is not that which can be the object of knowledge, but that (doesn't he tell us as much?) which creates our being and about which he teaches us that we bear witness to it as much and more in our whims, our aberrations, our phobias and fetishes, as in our more or less civilized personalities.
From Lacan's perspective, "that which creates our being" is radically Other. This Other cannot be returned to the same. In contrast to Hegelian difference, which is always a moment in an all-encompassing identity, Lacanian difference cannot be reduced to identity.'
(Taylor MC, Refusal of the Bar, in Lacan and Theological Discourse, 1989)