is Jungs' theory of synchronicity simply nonsense? I can make neither head nor tail of it. It is often quoted by 'new agers' as sign that we are all in a way "connected" (i.e networks for a higher consciousness, etc) and I feel that they have abused the original concept, but I myself can't even understand it.

Perhaps we might start with a distinction between two things the accusation of nonsense might mean. One is that it's patently false; the other is that there's no coherent idea. Your worry is pretty clearly the latter, and I'm sympathetic: whatever exactly Jung meant, it's hard to be sure that one has gotten hold of it. With that in mind, my sense is that there's an interesting idea behind the notion of synchronicity, though not one I'm inclined to believe.

Insofar as I understand it, synchronicity is meaningful coincidence. More particularly, it's meaningful coincidence between an inner state of mind and an occurrence in the outer world. By saying that synchronicities are coincidences, Jung meant that neither of the events causes the other. By saying that the coincidence is meaningful, Jung seems to mean two things. The first, and more obvious, is that the outer event corresponds in a meaningful way to the inner state. In one of Jung's well-known examples, a patient is recounting a dream about a golden scarab. At that moment, Jung heard a noise outside his window. He opened it, and a beetle flew in - one with an iridescent coloring that suggested the golden beetle of the woman's dream. Jung grabbed and and presented it to the patient, with the words "Here is your beetle." According to Jung, this led to a breakthrough in the woman's treatment. The apparently meaningful correspondence is clear enough. The second aspect of this meaningfulness is that such events are not accident or chance; not coincidence in the sense of what we might call mere coincidence.

This obviously raises a good many questions. One is why we should believe that cases like tjis are not mere coincidence. Jung seems to have thought that apparently meaningful coincidences happen more often than chance would predict. If that were true, it might provide some evidence for the existence of genuine synchronicities, though how one would go about collecting the evidence, let alone calculating the relevant probabilities is very hard to say. And even if we were able to establish that meaningful coincidences happen more often than chance would predict, it would take yet further argument to decide whether that such "connections" were cases of one event causing the other, or cases of both events having a common cause or yet some other sort of relationship.

Of course what Jung had in mind fits into a broader picture in which meaning is woven into the universe itself. In fact, Jung's outlook has more in common with the views of, say, Renaissance figures such as Marsilio Ficino or Heinrich Cornelius Agrippa than with the way those of us who admire science look at things. This is part of what makes it hard to get a grip on; we aren't used to thinking that way. For my own part, I don't share Jung's outlook, but I find the exercise of trying to grasp its outlines a fascinating one. I'm deeply skeptical of Jung's view, but I'm not prepared to say that the idea of synchronicity is simply unintelligible.

Read another response by Allen Stairs
Read another response about Mind, Philosophers