From a scientific viewpoint, causality is a concept that enables us to predict that such-and-such an event will soon occur as a consequence of an earlier event. For example, if you pour hot water on a ball of snow, it will start to melt.
In the context of mathematical statistics, there's another concept, correlation, which can be applied to sets of events that have already happened, with a view to demonstrating that they appear to be interdependent. You might say that, faced with correlated events, we suspect the existence of causal relationships, but we are not able to specify them precisely. In certain cases, observers discover correlations between series of events that could not possibly be related by causality. For example, we might find that a graph expressing variations in the price of lemonade in Sydney over the last decade is almost identical to statistics concerning the number of foxes killed by hunters in England. Pure coincidence!
In France, at the present moment, road safety authorities are dismayed by the fact that the number of deaths in accidents during the month of January was considerably higher than a year ago. Specialists immediately wondered why. Was there some causal factor behind this disappointing statistic? They have been unanimous in pointing out that there is indeed a strong correlation in France between road deaths and presidential elections. In other words, as strange it might seem, greater numbers of French drivers kill themselves when there's an election just around the corner. The suspected causal relationship involves the weird French tradition of presidential amnesties. In regalian style, one of the first acts performed by a newly-elected president is to grant amnesties to vast numbers of small-time delinquents and citizens who have committed petty misdemeanors such as parking their vehicle illegally or speeding. The alleged reasoning of pre-election drivers is as follows:
If I were to drive recklessly and get pulled over by a gendarme, I might be condemned to paying a fine. But when the new president arrives on the scene next May, he/she will wash away our sins by granting the traditional amnesty. So, there's no reason why I should worry about getting pulled over by a gendarme. So, I'll drive recklessly.
Now, that sounds a bit far-fetched. But experts swear it's a fact that French drivers "reason" in that weird way.
I'm particularly interested in another concept, not unlike correlation, known as synchronicity: a term applied to coincidental happenings that are so amazing that observers get around to wondering if these events were not brought about mysterious forces that we do not yet understand scientifically. A typical case of synchronicity is when you come upon an old letter from a friend whom you haven't seen for ages and, while you're browsing through the letter, the friend in question phones you. It's not surprising that many serious people consider that believing in a concept such as synchronicity is akin to believing in magic. But some scientists are prepared to admit that certain coincidental happenings are so extraordinary that it's tempting to imagine them as instances of situations that we do not master totally in terms of conventional probability theory. Most often, when such happenings are discussed among people of a scientific bent, they soon end up evoking things such as quantum events or Heisenberg's uncertainty principle.
My favorite personal synchronicity anecdote concerns the British novelist Lawrence Durrell [1912-1990], who was one of my heroes when I was a young man. I had heard that he lived in a village in Provence, and I imagined erroneously that the name of this village was Nîmes. In fact, Nîmes is a large city, and Durrell's village was located quite a long way away from the city.
[My misunderstanding was like that of a French tourist in Australia who, having heard that a friend lives in the bush to the north of Sydney, starts searching for his friend by taking a taxi to North Sydney.]
Be that as it may, I strolled around the heart of Nîmes, early in the morning, a little dismayed to discover that it was indeed a huge "village"... and nevertheless met up personally with Durrell, seated all alone at a café patio alongside the ancient Roman arena. Exceptionally, Durrell had driven into Nîmes early in the morning to get his automobile repaired. We spent an hour together, conversing about trivia such as Henry Miller's shock at the idea of having to use an outdoor dunny at Durrell's place, and Durrell's relatives in Tasmania who would regularly send him a crate of apples every year.
I've often imagined that I had this marvelous encounter with my novelist hero, not through mere chance, nor even through a causal chain of events, but rather because—somehow or other—I had "willed" that I should meet him there, at that place and at that moment. Now, call me crazy, if you like, call me unscientific... but I can think of no better explanation of this synchronicity.