To Hans Bender
Dear Colleague, 12 February 1958
Your prefatory note on synchronicity is perfectly adequate up to the point where you speak of the "synchronistic effect that was sought."
This effect was, if I may be permitted the remark, not sought at all but found, and it was found probably because the experiment was so arranged that the restrictions were reduced to a minimum;in other words, wide room was left for the play of chance.
If you give the "synchronistic arrangement" the smallest possible play, the play of chance is obviously restricted and the synchronistic "effect" thereby hindered.
The synchronistic phenomenon in my experiment consists in the fact that the classical expectations of astrology were confirmed in all three batches [of marriage horoscopes], which is extremely improbable although taken individually the figures are not significant.
Such a result has in principle nothing whatever to do with astrology, but could occur just as well in any other set of statistics.
The astrological experiment is by its very nature a lucky hit; were it not so it would have to be casual.
But presumably it is causal only in the most minimal degree.
You could therefore dismiss it as a mere lusus naturae if nobody wondered about the so-called chance.
The psychologist, who is concerned with the processes in the unconscious, knows that these remarkable "chances" happen chiefly when archetypal conditions are present, and it often looks as if the inner psychic disposition were reflected either in another person or in an animal or in circumstances generally, thanks to a simultaneous and causally independent parallel disposition.
Hence the accompanying phenomena in cases of death: the clock stops, a picture falls off the wall, a glass cracks, etc.
Until now such phenomena were furnished with ad hoc explanations and with names like telepathy, clairvoyance, precognition, psychokinesis, and so on.
But that explains nothing, even when certain of these phenomena are compared with radar.
I have never yet heard of a radar beam that could pick up a point in the future.
It is probably better, therefore, not to put forward any such ad hoc analogies or special fantasy hypotheses of this kind, but to lump together all these phenomena, which exceed the range of physical probability, under the uniform aspect of the meaningful "lucky hit" and to investigate under what emotional conditions these coincidences occur; and then, following Rhine, to demonstrate the existence of these phenomena with the largest possible numbers.
My line of inquiry aimed at the psychic conditions of their occurrence,and I rejected any semi-physicistic explanations in terms of energy.
I hope I have expressed myself clearly.
There is, if I may be permitted the further remark, no particular meaning in investigating marriages.
You could just as well observe a beehive and then, under a particular psychic condition, statistically determine the number of bees flying in and out, or watch a stony slope and see how many pebbles roll down.
It is obvious that, if you choose an experimental set-up that allows chance the least possible play, you will, if you conduct it skillfully, also get the least possible chances out of it; that is, you have effectively prevented a synchronistic "effect" from taking place.
It seems to be very difficult to form a picture of the Geulincx Leibniz lateral connection of events and to rid oneself of the causal hypothesis.
Chance is an event, too, and if it didn't exist causality would be axiomatic.
Meaningful coincidences present a tremendous problem which it is impossible to overestimate.
Leibniz as well as Schopenhauer had inklings of it [meaningful coincidences], but they gave a false answer because they started with an axiomatic causality.
With friendly greetings and best thanks,
C.G. Jung ~Carl Jung, Letters Vol. II, Pages 414-416