The Englishman Sir Isaac Newton, one of the greatest physicists of all time, has been reinvented. During the past 30 or so years, historians like Betty Jo Dobbs began to uncover the human behind the scientist and made discoveries that have surprised the world of science.

Newton has often been idolized, but at such a distance that he seemed a cold, remote and austere figure, like the marble statues that depict him. He was famous for basing his science strictly on what he could observe and measure. He mocked other philosophers whose premises and hypotheses were spun out of their own brains, and proudly hissed “I feign no hypotheses”. As a professor and later head of the Royal Mint in London, he seemed a ready-made, secular saint for science.

In the 1930s, boxes of Newton's unpublished papers were discovered in an attic and sold at auction. Their surprising contents led to some talk of a cover-up by his family and followers. As historians began to investigate these and other scattered papers, a new Newton emerged. They showed that he spent much of his time working, not on physics, but on alchemy: the magical search for a way to produce gold. Newton was in fact something of a transitional figure. He was halfwizard stoking his furnace and half-scientist covering pages of parchment with his sprawling mathematical calculations. Other papers showed that Newton suffered bouts of insanity.