A party that can foretell the future stands a very good chance of success. Given Labour’s record of U-turns, they cannot even foretell the present.

A state’s success in the ancient world depended on its mastery of natural resources: the more land and people you controlled, the more powerful you were. So states were frequently at war and naturally sought the favour of the gods – by consulting oracles, entrails and flights of birds, or striking lucky by means of dreams, omens, sneezes, odd events and suchlike. However, there were no guarantees. ‘A prophecy is the guess of a sensible man’ (Euripides), ‘No good has ever come from prophecy’ (Aeschylus). Menander hit the spot, when a character desired ‘A future not as I wish, but to my benefit.’

But divine intervention meant little to Herodotus, who travelled from Egypt to Persia researching the Persian wars (490-479 BC), or to Thucydides, witness of Sparta’s war with Athens (431-404 BC). For Herodotus, men at war were behaving as men did in normal life: if spurned or crossed, they took revenge; if helped, they had debts of gratitude which it was their duty to repay. The big question was ‘Who started it all?’ and reciprocation was the name of the game. Gods did loom in the background but not in any significant way.

Thucydides was the first historian to deny gods any role at all. Since no human could understand the mind of a god, history could be useful only if understood in purely human terms. For him, as a non-combatant, exiled Athenian, the war that he explored so compellingly from both sides arose from Sparta’s fear of Athens’s expanding power. The human condition being constant, such patterns of behaviour were likely to recur (Thucydides may have been thinking of doctors tracing the course of diseases). If so, those who were on the lookout for such ‘case histories’ could be in a position to foresee the possible course of events.

Given Labour’s track record, we urgently need a dedicated Department of Profitcy to check out the costs and feasibility of all Labour’s plans, starting with their 1.5 million homes and expanded Northern Rail (in 2030!). And the odds on that…?