'And yet it's not simple at all,' Daniel said. 'It follows simple rules – it obeys logic – and so Natural Philosophy should understand it, encompass it – and I, who know and understand more than almost anyone in the Royal Society, should comprehend it. But I don't. I never will . . . if money is a science, then it is a dark science, darker than Alchemy. It split away from Natural Philosophy millennia ago, and has gone on developing ever since, by its own rules . . .'