The question at issue between science and faith is, as we have said, not whether it is possible to gain trustworthy knowledge of the world without faith, without making assumptions, for science itself is built on faith in the reality of things and the uniformity of Nature, but whether the assumptions of science are the only assumptions that we need make. One way of proving that they need not be assumed would be to show that they can be proved by science. But that way failure lies, as is shown by the optimist's ill-success. But there is yet another way of cutting down the common faith of mankind to the narrower creed of science, and that is to show that the remaining articles of faith, the assumptions not necessary to science, are inconsistent with science. That is the method adopted by the Pessimistic Evolutionist. He does, indeed, go further with the common faith than the optimist did. Impressed by the failure of the optimist to exhibit the laws of morality as the mere outcome of the laws of Nature, and the reality of our moral ideals as derived from the reality of material things, he accepts the common faith of mankind in the law of morality as being just as rational as his and their faith in the uniformity of Nature. But having taken this one step, having adopted this additional article of faith on faith, he refuses to go any further. He accepts without evidence the assumption that there are certain things which we ought to do, just as he accepts without evidence the assumption that Nature is uniform. But he refuses to accept the assumption that will is free, because that is opposed to the evidence. He admits that we ought to choose certain things, but denies that we can choose them; and his forecast of the future is in accordance with the premises from which it is inferred. It is a pessimistic picture of man being steadily driven to do the things that he ought not, ending with the triumph of what must be over what ought to be, of physical necessity over the morally right.