Lacan's existentialist leanings show in his development of the antirealism he finds in Freudian writing about the contents of the unconscious. One can argue that if the psyche is shaped under the joint influence of (i) the interaction between the environment and the organism; and (ii) the significances attached to the brain—world interaction, then, the contents of the psyche may change over time as a result of self-transformations in the subject. And if the psyche is a holistic system (the manifestation of a multiply interconnected multileveled associationist system) then those changes could be quite profound. The possibility (downplayed by Freud) is that, as one's grasp of language and the complexities of social life are refined, one's psychic life and its contents, even at the level of unconscious, is reconfigured.
This is meat and drink to existentialists (such as Sartre) who argue that the inertia and "thingness"(being-in-itself) of the unconscious mind represents a major defect in Freudian theory. Existentialists argue that the articulation of psychic or mental content implicates the conscious subject and that the deterministic or biologically driven Freudian unconscious is a myth. Indeed, the holism of a connectionist system yields a very plausible reading of this claim.
At certain points, the conjoint effect of the encounter with the environment and the higher cognitive structure introduced by signification might result in indeterminate (but causally potent) psychic material functioning as envisaged [End Page 64] by Freud. The work of psychotherapy would then be to enable the individual to confront and articulate this material so that the consciously lived narrative more adequately integrates important moments of the ongoing encounter between subject and world. If we import associationist holism into this, then we see that the contents of the mind are radically subject to revision as long as they can be accessed in a sufficiently potent manner.
Both Lacan and Jaspers pick up the hints of antirealism in Freud's writing about the unconscious so as to open the way for a view of this kind. But Lacan also imports a variety of structuralism, so that any tendency to see the existential individual as transcendent of actual worldly existence is undercut.