On the concept of Intimacy: the relational dimension in which the internal worlds of human beings can communicate physiologically with one another and exchange contents, feelings, and thoughts. The role of the mucoses and their psychic equivalents. The potentially positive (= necessary) and negative (= fixative) aspects of symbiosis and healthy dynamic fusionality. The place of the analyst in the psychic equivalents of the intercorporeal interactions: the Interpsychic.