The term conversion, proposed early on by Freud, designates the passage of a psychical expression to its somatic manifestation. The author recalls why he has proposed a wider conception of this term, which would extend the capacity for conversion to include a potential that is intrinsic to the symptom as structure. He then raises the question of the status of this notion in adolescence. At this age we see not only conversions in the strict sense of the term, but the long process one must go through often assumes some feature of conversion in its larger sense. This trajectory is commented upon using a case of transitory soliloquy, already evoked in an article about shame, which is related to a conversion of the philosophical or religious type. This serves as an opportunity for pointing out the respective roles played by ideals, affect, and fantasy, the « stranger other », and especially, to be more precise about what the capacity for conversion consists of. It is a spring that ensures the containment of precocious seductions, and of the reactions to these, giving the subject the ability to regress and rebound, to close up and reopen, indispensable to anchoring him in the universe where he is called to live.