To judge from current events in the Middle East, the god of Israel appears to be battling the god of the Palestinians, even though they both seem to be the same god. But are they guiding events? And if not, why not? The Greek historian Thucydides (d. c. 400 bc) had no truck with the idea.

In his account of the long war between the two most powerful Greek city states of their time – democratic Athens and oligarchic Sparta (431-404 bc), each with their respective allies – Thucydides was the first historian we know of to discount divine intervention in human affairs. Naturally he reported on the widespread phenomenon of religious belief among the Greeks and the use to which it was put. When, for example, a dreadful plague struck Athens in 431 bc, he described its symptoms and effects in clinical detail and men’s belief that it fulfilled an ancient oracle, but never assigned it, or any other occurrence, to divine intervention.

He justified this approach in the introduction to his history by claiming that what made his work useful (and of eternal value) was the fact that he had gone to the very best of his ability to construct his account of the war solely on the basis of the experiences of those who were actually involved in it. This enabled him to make generalisations, drawn from hard evidence of human behaviour and interaction, from which he felt it was possible to make judgments about how human past behaviour, given the same set of human circumstances (there’s the rub), would be a likely predictor of their future behaviour. But if gods intervened in human history, it would be impossible to draw any hypotheses about what outcomes might emerge from any particular set of events. For how could we know the mind of a god?

This is an observation of the very highest intellectual importance. But it raises the question – does it make any difference? After all, gods or no gods, it is men’s belief about gods that could be seen to be driving events, and that, as Thucydides saw, is a human behaviour that is as powerful today as it has been over the whole of human history.