Some of those who read Sartre's lecture on Kierkegaard "L"universel singulier"¹ were surprised to find there the notion of transhistoricité (transhistoricity). Yet it is this notion and the argument based upon it which offers in my opinion the key to a true understanding of J.-P. Sartre's writings in the late fifties and the sixties, mainly Questions de méthode (QM) and Critique de la raison dialectique (CRD).²