The Greek notion of kairos, as it was problematised in the 5^th and 4^th centuries B.C.E., a notion that has continued to enjoy a good fortune until today, allows us to qualify the conditions for the psychoanalyst’s intervention in a cure, namely, at the right time. In other words, the intervention must take place at a time whose subtle character is often noted by Freud in his written work. This occurrence escapes chronology’s linear time. But whereas for Freud the right time is discerned on the basis of a know-how that determines the psychoanalyst’s adroitness, according to Lacan, it appears as a propitious scansion, thus emerging as much from contingency as from disengagement from such knowledge. Although the polysemy of kairos integrates this variety of aspects, the fact remains that such aspects differ and even oppose one another because of what they imply, respectively, about the nature of the unconscious.