This morning, when I opened my window somewhat clumsily (and thus noisily), a bird that had been sitting on the terrace was startled and fluttered away.
A couple of weeks ago, I had a sudden impulse to call a friend from my university time and catch up (I hadn’t heard from her in months). Now curiously enough, on the evening of that same day I received an email from another friend, from that same time period in my life, who wanted to catch up (I hadn’t heard from her in months, too). Speak about coincidence …
1. There seems to be some confusion about the difference between the terms ‘synchronicity’ and ‘synchronicities’. So let’s see if we can sort that out, using the two examples above.
What I want to focus on, in each of the examples, are two events (each): in the first example, my opening the window, and the bird fluttering away; in the second example, my calling one friend and my other friend’s writing an email. In each of the examples, the two respective events are related, but they are related in different ways.
In the first example, my opening the window (with the resulting noise) caused the bird to fly away. However, in the second example, there is nothing like that: that I called one friend from my university time can hardly have caused the other friend to write me an email (the latter friend could not have known about my earlier call). And since I did the call before I received the email, my impulse to make the call also wasn’t influenced by the email. There really seems to be no connection in terms of cause and effect — merely a coincidence.
As a coincidence, however, it is relatively improbable. (Not mysteriously improbable; but the probability is low.) It is even more remarkable because there are meaningful connections between the two events in the second example: they are both my friends, the connection stems from the same period in my life (my university time, which is not that recent), there had been no contact for a while and thus an interest in catching up had built… Moreover, the whole constellation (that the events in fact happened together) seems meaningful in itself: it is, so to speak, as if something or someone in the external world wants to ‘tell me something’, perhaps that I should be in contact with my friends more often, or perhaps that I should revive my old university ties. Note, however, that all this is very subjective: the connection is meaningful only to me, personally.
Pulling it all together, we have, in the second example, a synchronicity: a pair of events, happening (roughly) at the same time, with a rather low probability of occurring together, and a certain feeling of meaning in someone who experiences the coincidence. That is basically what we mean by synchronicities: unlikely, but meaningful coincidences. In contrast, in the first example there is nothing coincidental and nothing meaningful, just two events, related to each other as cause and effect, i.e. an instance of causation.
2. That we speak about synchronicities is because the term was coined by Jung, in his famous essay on that topic (published in 1952 in a small book called Naturerklärung und Psyche, together with an essay by Wolfgang Pauli).
However, Jung does not usually call (what we today often call) ‘synchronicities’ that. He mostly just speaks of coincidences. Then where exactly does the term come into play?
Jung thought that (what we today often call) synchronicities cannot be explained using only the principles and categories which we have, in particular: space, time, and causation. With just these, our understanding of nature will be incomplete. Our view of nature, for Jung, has to include the nature of consciousness and the unconscious, that is, the subject area of psychology, just as well as those areas studied by biology, chemistry, and physics. But especially such phenomena as the ‘meaningful’ coincidences sometimes escape an account in terms of space, time, and causation.
Therefore, Jung concluded, we need an additional category (or principle), besides causality, in order to complete our understanding of nature. We would only bring it in where an explanation in terms of causality cannot be found (in fact, is impossible); and Jung thought there are such situations (synchronicities being an instance of them). He called this additional principle synchronicity.
Hence the title of his essay: “Synchronizität als ein Prinzip akausaler Zusammenhänge” [“Synchronicity as a principle of a-causal connections”, GW VIII, 457-553]. That essay is not (just) about synchronicities, it is primarily about synchronicity, the principle — and his argument that we need such a principle in addition to, and on a par with, the principle of causality.
3. Needless to say, one can agree with Jung on one thing, namely: that there is an interesting class of phenomena called synchronicities (roughly: meaningful coincidences), which is worth investigating and hopefully can at some future time be rendered explainable; and disagree with him on the other, namely: that in order to explain synchronicities, we must postulate a new principle in the order of reality called synchronicity.
The latter is a separate argument whose merits can be checked independently. That requires a deeper engagement with Jung’s original text, of course, as well as with his premises. (In other words: stay tuned!)
Most of the time, however, when books and articles nowadays discuss the topic, they are not interested in Jung’s additional principle, but only in the phenomenon itself, i.e. synchronicities. (Though, a little confusingly, they sometimes use the term ‘synchronicity’ when they mean just that, i.e. they use it in a somewhat different sense than Jung did. That’s just what happens when language develops over seven decades.)