If, in 1930, Adolf Hitler had been killed by the truck that crashed into his car, would the Second World War have happened? That is the question that opens this startling book. We assume Hitler was such an evil man that the world without him would have been better, or at least different. On the other hand, Germany had been crushed by a cruel peace treaty in 1918 and the economy all but destroyed by hyperinflation in 1923. Even without a bellicose leader, the country would still have had reason to fight.

Do leaders determine events or do events determine themselves? Nobody is better placed to answer this question than Jared Diamond. He is now eighty-eight, but undimmed as an asker of awkward questions to which he comes up with awkward answers. In Profits, Prophets, Coaches and Kings, he pursues the effectiveness of leaders – but first, there is his Hamlet obsession.

Shakespeare, he argues, was the greatest playwright of his time. Hamlet is a play ‘that no [other] Elizabethan … could have written’. A leader in a given field must possess talent to a degree unmatched elsewhere. This working definition allows Diamond to dismiss the claims of Jeff Bezos, Bill Gates,