known to exist, happened to be published on the very day that a new planet was discovered. The mathematical method, then, is at the present day without a rival. But, although we cannot at present imagine what could replace the mathematical method, we must be careful not to exaggerate the significance of the results that have been achieved by it. For these results depend not only on the method, but also on the material the method has to work with. And there is good reason to suppose, in the present state of physics, that the material with which science has worked hitherto is turning out to be not quite satisfactory. This material is chiefly the Newtonian set of abstractions. Newton postulated, as the fundamental constituents out of which the perceived universe is built up, Space, Time, and Matter. Space and time he regarded as absolute and as quite independent of matter. Matter was an enduring substance that simply inhabited space and time. The analysis of these conceptions has resulted in the Einstein theory, in which neither space, time, nor matter are fundamental. The interesting thing about this analysis, from our present point of view, is that it shows clearly what arbitrary elements are present in the scientific description of the universe. For we must remember that moral and æsthetic elements were ruled out of the real universe simply because science did not find it necessary to mention them. The foundation stones of the scientific edifice, namely space, time, and matter, were supposed to be the only realities. Everything else was a sort of illusion. Men who must have been theory-mad soberly maintained that little particles of matter wandering about purposelessly in space and time produced our minds, our hopes, and fears, the scent of the rose, the colours of the sunset, the songs of the birds, and our knowledge of the little particles themselves. The sole realities were the little wandering particles and the space and time they wandered in. The existence of everything else depended on the mind, and was inconceivable without the mind. It is interesting, therefore, that science has now reached a position where space, time, and matter also depend on the mind. In giving a scientific description of the universe Einstein does not find it necessary to begin with space, time, and matter. These entities become “derivative”. The universe becomes more spectral than ever if we are going to adopt the materialist principle that what depends on the mind does not really exist. Even the universe of wandering particles is comparatively cosy compared with this modern universe of undefinable “point-events”. But if we do not adopt the materialist principle we may assert that moral and æsthetic values are as much a part of the real universe as anything else, and that the reason why science does not find it necessary to mention them is not because they are not there but because science is a game played