When Wittgenstein moved from Manchester to Cambridge he was following a path from the study of the natural sciences to the study of philosophy which was then not unusual, and has since become increasingly common. Russell had preceded him in that intellectual emigration and many more were to follow. Of the three philosophy departments I have been in, two were headed by natural scientists (and the third by an historian). Both my research supervisors in philosophy were natural scientists (as I was myself). Less surprising, but still significant, a considerable proportion of Presidents of the British Society for the Philosophy of Science were originally trained as natural scientists. Yet it is a subject still unrecognized by the Royal Society. The editors of both the British Journal for the Philosophy of Science and the journal Analysis were both originally natural scientists. Eminent scientists seem to feel impelled to discuss there own subjects in a wider context of philosophy. Bohr, Schrodinger, Kilmister, Hoyle, Hawking and Penrose, are but a few from a long list.