To Evelyn Thorne
Dear Miss Thorne, 23 March 1955
Thank you very much for your interesting letter.
I can confirm your observation from my own experience.
Time and again I have observed that when I was busy with a special thought or a work of a remote kind, I found that the theme was picked up in newspaper articles or in letters I got from strangers as if it has been broadcasted.
Sometimes this observation was so striking that I myself thought of the possibility that it might be a case of synchronicity.
But your observation of the colours worn by people in a crowd shows that it must be a matter of the accumulation phenomenon in chance series.
You can observe this fact easily when you watch the traffic on roads where it is not continuous.
You will notice that cars or pedestrians have a marked tendency to come in aperiodic batches interspersed with solitary pedestrians or cars.
These accumulation phenomena are just chance occurrences.
Thus we have to consider the coincidence of themes in manuscripts or newspaper articles in the first place as mere chance, although with a certain mental reservation.
At the time of Immanuel Kant there were quite a number of philosophers with a very similar kind of mind, and also at the time of Charles Darwin there were at least three other minds at work to produce similar ideas independently of each other.
In such cases one feels tempted to think of a peculiar Zeitgeist secretly at work and pushing forward certain instrumental individuals.
Unfortunately, this hypothesis is difficult to prove, yet it seems to me as if the latter phenomena were somewhere midway between mere chance occurrences and positive synchronistic phenomena.
By the way, my essay on synchronicity will soon be published in English translation by the Bollingen Press.
Thanking you again,
C.G. Jung ~Carl Jung, Letters Vol. II, Pages 233-234.