In 1892 the iconoclastic American philosopher C.S. Peirce proposed ‘to examine the common belief that every single fact in the universe is determined by law’. ‘The proposition in question’ – he called it the doctrine of necessity – ‘is that the state of things existing at any time, together with certain immutable laws, completely determines the state of things at every other time.’ His examination was venomous. At the end: ‘I believe I have thus subjected to fair examination all the important reasons for adhering to the theory of universal necessity, and shown their nullity.’ That was only the negative beginning. Peirce positively asserted that the world is irreducibly chancy. The apparently universal laws that are the glory of the natural sciences are a by-product of the workings of chance.

Peirce was riding the crest of an antideterminist wave. As is so often the case with someone who is speaking for his time, he thought himself alone. ‘The doctrine of necessity has never been in so great a vogue as now.’ He did warn against supposing ‘that this is a doctrine accepted everywhere and at all times by all rational men.’ Nevertheless he had to peer back into the distant past to find people with whom he agreed. The philosophy of Epicurus and the swerving atoms of Lucretius were, in his opinion, precursors of the statistical mechanics of Maxwell, Boltzmann and Gibbs. He had more allies than he imagined, but he was right in thinking that his examination of the doctrine of necessity would have been unthinkable in the eighteenth century.