A large part of science is purely utilitarian; in the jargon of popular journalism, it is concerned with harnessing the forces of Nature to the service of man. The science of to-day is unable to give any decisionis unable even to produce any evidencein the long-debated question of deter-minacy. Nature is completely determinate, because it consists of particles which move about in space under unbreakable laws such that the motion of each particle is determined solely by the state of the system. The arguments of Copernicus have fallen on barren soil, like those of Aristarchus eighteen hundred years earlier, had not the telescopic discoveries of Galileo provided visual confirmation of their truth, or at least of their extreme plausibility. Some branches of science which are purely intellectual; the forces of Nature; their contribution is to gratify people intellectual curiosity as to the universe in which their lives are cast, and help they assess and understand their relation to that universe.