The idea that there is a conflict between science and art, which is at bottom the idea that there is a conflict between science and mysticism, rests, I have suggested, upon an old-fashioned conception of the status of physics. The first duty of a man who bases his conclusions on science is to make sure that his science is up-to-date. The science that leads to the depressing conclusions I have just sketched is not up-to-date. Until a few years ago the physicist thought that the material universe he dealt with was a real, objectively existing universe in the sense that, in the absence of consciousness, it would be very much the same as it appeared to be. This universe was subject to laws, and these laws might conceivably have been different. There was no _a priori_ reason, for instance, why the force of gravitation should not vary as the inverse cube of the distance. There was no _a priori_ reason why matter and energy should be conserved. These were laws of governance of the material universe; their discovery had required much effort and the rejection of alternatives. Man was in no sense responsible for them: he happened to live in a universe governed by them. These were the iron laws of the Victorians and are the laws, apparently, that depress modern poets. One of the great discoveries of relativity theory is that these laws need be no more depressing than the laws of Euclidean geometry. No artist has felt his aspirations baseless because he cannot draw a circle whose circumference is six times its radius. He has no more right to despair because there is an inexorable law of gravitation. This has been made clear by Professor Eddington, whose mathematical development of relativity theory is of great philosophical importance, and would, in a more adequately educated community, be given more newspaper headlines than Tutankhamen. The real universe, according to relativity theory, is a four-dimensional world of point-events. Of the nature of point-events we know nothing. All that we require to know, for the purposes of physics, is that it takes four numbers to specify a point-event uniquely, and that some kind of structure――a minimum amount of structure――may be postulated of the world of point-events. We then find, purely by mathematical processes, that certain characteristics of this world will have the quality of permanence. The mind, faced with this world of evanescent point-events, selects those characteristics that are permanent as being of special interest. This is merely because the mind happens to be that kind of thing. As a consequence of this predilection of the mind there arises space and time, matter, and the laws of nature. There arises, in fact, the “objective universe”. The real world of point-events has many other characteristics to which the mind pays no attention. A different principle of selection, exercised on the same total world of point-events, would result in an utterly