As a consequence, at some point in the future, something big will happen - George Bush's brother Jeb will invade Belgium, or Britney will team up with Wayne Rooney to record "We're a Couple of Swells".
Edward Lorenz's "Butterfly Theory" is an attractive one. Did you ever wonder, for example, just how we got to where we are, in a highly regulated regime with a national curriculum, prescribed lessons and the most comprehensively tested children in the world? Where's the butterfly flap that brought us here?
One candidate, for me, is found in the pages of the Auld Report, which appeared in 1976. Commissioned by the Inner London Education Authority, the report arose from an investigation by Robin Auld, QC, into "the teaching, organisation and management of the William Tyndale junior and infant schools, Islington".
What became known as "The William Tyndale Affair" began in January 1974 with the appointment of Terry Ellis as head of the junior school.
Mr Ellis, with deputy Brian Haddow, a strong-minded and able teacher with radical views, was soon running a highly progressive team-teaching regime that gave children a great deal of choice and freedom. It was essentially a system, much debated at the time, called the integrated day.
With hindsight, it's clear that while it could work well with gifted teachers and good leadership, in the right sort of building, it could just as well be a recipe for chaos. The result is described in the excellent William Tyndale: Collapse of a school - or a system? by TES journalists Mark Jackson and John Gretton, published with admirable speed by Allen and Unwin in 1976 as a TES Special. "No place in the school was put out of bounds to them (the pupils), not even the staff common room and lavatories.
They were allowed to eat sweets whenever they wanted, wherever they wanted.
To all intents and purposes there were no rules at all."
The school quickly became the focus of dissent and conflict. Those teachers who didn't agree with what was happening made their views known - in one case by making common cause with disgruntled parents, fomenting discontent in a way that even the Auld Report called "disgraceful".
Parents, for their part, voted with their feet and the roll plummeted. The press had a field day ("The School of Shame") and the authority, in the absence of any clarity about its role in the management and teaching within its schools, ran round in circles wringing its collective hands.
It's impossible to resist the conclusion that it was all down to a failure of leadership, either within the school or the authority, or both, on a scale that just wouldn't be allowed to develop now. For one thing, today's schools face up to performance criteria that simply didn't exist in the 1970s. "It is difficult to talk of assessing the performance of teachers when there is no agreement on what teachers are supposed to be doing,"
wrote Jackson and Gretton.
They concluded that the answer lay with the Government - only it could bring the local authorities to heel and set some rules for judging schools.
"After William Tyndale, the Secretary of State can no longer pretend, as he and his predecessors have so often tended to do, that it is all happening somewhere else," they wrote.
So, for good or ill, the Government sat up and began to take a grip. In October 1976, hard on the heels of the Tyndale business, Prime Minister James Callaghan made his keynote Ruskin College speech, raising doubts about what he described as, "the new informal methods of teaching, which seem to produce excellent results when they are in well-qualified hands but are much more dubious when they are not".
So it was that, painfully but irresistibly, we edged towards the Education Reform Act of 1988, the national curriculum, assessment, and all that has followed.
You can read the message of the Tyndale butterfly in various ways. Perhaps it was a much needed catalyst for the restoration of order from imminent chaos, and the development of a strong framework within which leadership could operate. Or, on the other hand, perhaps those teachers, by taking too radical an approach to freedom and choice, opened the door to the new authoritarians and, in doing so set back, perhaps permanently, any prospect of a truly progressive approach to teaching in our primary schools. What do you think?
Gerald Haigh is a former headteacher