I was walking down the street thinking about a friend I hadn’t seen for some time, and when I looked up, there was my friend standing at the corner with his wife and he was looking at me in some surprise, for as it turned out they had been speaking of me in the same moment that I had been thinking of him, and so we congratulated ourselves on having arrived there at the corner at just the right moment for these facts to be revealed to us. We talked for a while, as there were many things that we had been meaning to discuss were we ever to run into each other precisely as we had just done, and when we parted I had the happy sense that the substance of my day had been revealed. Only later did I recall that none of us had referred to our fortunate meeting as a coincidence, which is what it was, of course. But coincidence is a word that we have learned to distrust, a term of mild derogation employed by parents, teachers and other grown-ups to dismiss the marvellous: “only a coincidence” was the way they usually put it, and in that word only we understood meaning and significance to lie not in the world of the coincidental, but elsewhere, in a more real world of non-coincidence, in which events could be held accountable according to an iron law of cause and effect. What was never pointed out to us was that coincidence required perception in order to exist: it was a function of our looking at the world. If my friend and I had not seen each other there would have been no event: this is perhaps what troubled the rational minds of grown-ups, who believed an event had to be an event whether or not it was perceived to be one in the first place.

On another day I had been trying to write a story about the British Israelites, a Protestant sect whose followers were convinced that Anglo-Saxons were the lost tribes of Israel, and I had developed the uneasy feeling that there was much about British Israelites that I would never understand. I left my desk and went for a walk along an unfamiliar stretch of Kingsway Avenue occupied by Asian grocery stores and restaurants and electronics shops, and became lost in thought; when I looked up I was standing outside an aging storefront in the window of which lay a map of Europe and North Africa on which curved arrows had been printed to indicate, as I soon saw, the movements of the same lost tribes of Israel that I had been reading about. They surged up across Europe and the English Channel and then across the Atlantic Ocean: I had stumbled onto the British-Israelite World Federation Bookstore, the proprietor of which was a red-haired man with a beard who was pleased to fill me in on the present state of the Israelite movement, which he said was still alive in certain circles. Among other documents, he showed me a pamphlet containing a speech given by a local scholar and businessman in which the Jewish origins of the Japanese people and the Shinto religion had been explained to the public on March 28, 1932, in the Oak Room of the Hotel Vancouver. I bought the pamphlet for two dollars, and as I walked home with my souvenir I felt as if I were returning from a dream. Coincidence is the glue of dreams, and that dreamlike quality may be what makes a coincidence so difficult for rational minds to account for: a coincidence is always somewhat ludicrous; it makes us feel laughable. In a moment of coincidence the world seems, however gently, to be mocking us.

And so we speak with caution about coincidence (Wittgenstein avoided the word entirely by speaking of “concomitance” instead). How many times have events like the ones I speak of been demoted from the real world by being dismissed as mere coincidence? Not long ago on the radio I heard a man brush off a rather wonderful coincidence in his own life as being but the product of “random chance,” as he put it. What, we want to ask him, constitutes the non-random chance? Is there a world of intended occurrence? Three of the four dictionaries within my reach define coincidence as events “apparently accidental” happening “without apparent causal connection,” “apparently by mere chance”; the fourth is even more skittish: "an event that might have been arranged although it was really accidental." None of this helps us understand what the non-coincidental might be, or might, as the lexicographers put it, apparently be.

Coincidence invokes the spectre of cause and effect, a set of rules poorly understood by modern, non-Newtonian physics, and it reminds us of the photon that exists as a wave or a particle depending on how you look at it. Perhaps behind a fear of coincidence is a fear of magic passed down to us by the age of Newton, but magic is unnecessary to understand a world that proceeds by the rules of cause and effect: evolution and entropy follow these rules, and so does coincidence, which is made marvellous precisely because those same rules are the mode of its coming into being. Here perhaps we approach the heart of the matter: the rules merely define a system; of themselves they cause nothing. Coincidence is a flaw in the tangled blur of cause and effect that we see when we look out at the world: suddenly the world looks back at us in a moment that has no explanation, that is defined only by our perception of it. In such a moment everything is changed but nothing is different. Perhaps this is why there are no monuments to coincidence, although coincidence informs the life of each of us.

Last week I met friends from out of town in a downtown bar and told them stories of an old mentor of mine who twenty-five years ago had been an important force in my life. The music in the bar had become funereal, and when we asked the bartender about it he shrugged and made a joke about a funeral parlour. When I got home I picked up a magazine from the stack in the bathroom and it fell open at an elegy written in memory of the man I had been telling stories about, my old mentor, and I understood at that moment that he was no longer alive. The magazine was six months old; the poem, written by his daughter, would be how much older than that?

I lit a candle to honour the man whom I had loved but had not seen since 1986. His name was Richard Simmins and he had been a curator and an art critic before moving to the Ottawa Valley to become an antiquarian book dealer, and he was a writer of some power. ("We all laughed at the photograph of the surrealist insulting a priest," he wrote in a poem in 1974, and I copied the line into my journal.) He once gave me a 1958 Pontiac in return for some small favour; I drove it for six months and sold it for a dollar in the Cecil beer parlour when I didn’t need it any more.

That was the summer I used to go to the racetrack with my brother to place bets, on the advice of an astrologer who had worked out a way of predicting winners based on the positions of the planets and the timing of the starting gun. It took a few weeks to adapt to the system, and when we were ready and had chosen our day, the astrologer calculated that the first race, if it started on time, would bring in horses six and three, which, as I recall, were controlled by Mars and Mercury, and after that the following races would come in like clockwork.

My brother and I set out in the Pontiac with our charts and my girlfriend, who became unpleasantly negative as we drove across the city and eventually I had to pull over and ask her to get out of the car. She had no money so I gave her cab fare. The Pontiac ran out of gas a few blocks from the track and we had to push it into a gas station and pour a few gallons into the tank; the parking lot at the track was full so we drove onto the street to park, and then ran back to the gate to pay the entrance fee. We were within a few feet of the betting window when the bell rang and the race went off before we could place our bets. Mars and Mercury came in just as they were supposed to do. We could see then that the system worked, but we couldn’t see that it didn't work for us: we followed up the consequences of the first win as our advisor had directed us, and broke even in the second and third races.

The fourth race was a big one, we had been warned, and Mars and Mercury would play a part in it. My brother took our money to the wicket to bet on six and three both ways. I looked out at the track as the horses came up to the post; among them was a white stallion, a rare sight at the races, and it carried the number four on its back: four was the number of the moon, which according to our advisor always played a role in the fourth race. It was also an extreme long shot. I looked out to the east where the moon, nearly full, could be seen hanging in a blue sky. I said to myself: white horse, white moon, four in the fourth race, and then I said: it’s only coincidence, and manfully, rationally, resisted the impulse to call my brother back (I was the eldest, and perhaps the more addicted to the unbending lever of logic). The white stallion won the race handily, separated from the pack by six and three, who seemed to be running interference for it, and my brother and I failed to win many hundreds of dollars.

Thirty years later, I read in a layman’s book on quantum mechanics that what we experience of the world is not external reality at all, but our interaction with reality.