To J. B . Rhine
Dear Dr. Rhine, 9 August 1954
Thank you for your kind letter.
The English translation of "Synchronicity" will be published by the Bollingen Press
The translator is Mr. Hull, who is translating my Collected Works.
He has a fair understanding of the synchronicity concept, which au fond is not complicated at all and has its long history
reaching from high antiquity right down to Leibniz.
He had still four principles for the explanation of Nature, viz. space, time, causality, and his harmonia praestabilita, an acausal principle.
My doctoral thesis was published, if I am right, in my volume Collected Papers on Analytical Psychology (znd edit., 1920).
(I am actually not at home.)
The main difficulty with synchronicity (and also with ESP) is that one thinks of it as being produced by the subject, while I think it is
rather in the nature of objective events.
Although ESP is a gift of certain individuals and seems to depend upon an emotional perception, the picture it produces is that of an objective fact.
This truth becomes highly problematical in the case of precognition, where a fact is perceived that apparently does not exist.
As one cannot perceive a fact that does not exist, we must assume that it has some form of existence, so that it can be perceived nevertheless.
To explain it we must assume that the (future) objective fact is paralleled by a similar or identical subjective, i.e., psychic, already existing arrangement which cannot be explained as an anticipatory causal effect.
But it is quite possible and, as a matter of fact, you have shown it to be possible, that the subjective parallelism can be perceived as if it were the future fact itself.
The harmonia praestabilita would be in this case the obvious explanation.
I think that all forms of ESP (telepathy, precognition, etc.) including PK have essentially the same underlying principle, viz. the
identity of a subjective and an objective arrangement coinciding in time (hence the term "synchronicity" ) .
With my best wishes,
C.G. Jung ~Carl Jung, Letters Vol. II, Pages 180-181.