In his conference, Paolo Fonda highlights the concepts of “micro-area of fusion” and of “separation coefficient”, which makes it possible to think in terms of quantitative factors. The perspective of the gradualness of some mechanisms or phenomena implies the existence of a theoretical continuum between psychotic and neurotic functioning. Another aspect addressed concern symbolic component versus concrete elements of the communication, and ambiguity as a way of moderating reality. Authors of prose and poetry are brought to support this psychoanalytic thinking.