The private correspondence between Wolfgang Pauli and Carl Gustav Jung, which lasted from 1932 to 1958, represents the first research on the interaction between mind and matter operated by disciplines considered until then very distant. The Jungian concepts are, in that quarter of century, revisited and partly redefined by the critical and productive incentive of the scientist. Their research, branching out in many directions, perhaps reaches its climax in the development of the principle of synchronicity, observed by Jung in his work, as an interpretation-explanatory principle complementary to the principle of causality. The relevance of their work, open to new scenarios and to "a new idea of reality", is testified by the comparison, here just outlined, with some research and theories both in physics and in neuroscience.
Keywords: Neutral language between physics and psychology, synchronicity principle, structural induced correlations, observation process in physics and psychology, reduction of symmetry