One of the basic intuitions guiding Sartre's phenomenological works is that phenomena cannot be reduced to essences that are separate from appearances. Such a separation leads to a type of semiotic profusion that Sartre criticizes in L'Etre et le néant by evoking the example of Proust. Sartre's ontology must avoid this infinite proliferation of meaning without falling into a type of essentialism where things are merely what they appear to be. Sartre's references to Proust demonstrate not only the pitfalls of essentialism and unlimited semiosis, but also why Sartre found it necessary to invent existential psychoanalysis as a response to the twin phenomenological challenge of situating intentional meaning neither on the side of the object, nor of the subject, but somewhere in between. The unsatisfactory nature of Sartre's solution is palpable in the contradictions we discover in his observations on Proust.