As soon as the dialogue between two people touches on something fundamental, essential, numinous, and a certain rapport is felt, it gives rise to a phenomenon which Lévy-Bruhl fittingly called participation mystique. It is an unconscious identity in which two individual psychic spheres interpenetrate to such a degree that it is impossible to say what belongs to whom.

The Collected Works of C.G. Jung: Civilization in transition (ed. 1964)