C. Jung in his paper on synchronicity wrote that the unconscious also contains subconscious perception and forgotten image-memories which cannot be retreived at the moment, and probably will never be retrieved. In the contents of the unconscious we should distinguish perception, which I would name “inexplicable knowledge” or “spontaneity” of mental images. Nevertheless, however incomprehensible it may seem, we are eventually compelled to assume that the unconscious contains something like a priori knowledge or “spontaneity” of events which do not have any causal basis. In any case, our concept of causality is of no use for an explanation of these facts.