Thus far, then, by taking the environment into consideration, we seem to have introduced no new factor into our conception of progress. It seems that when I wake up from childhood's slumber I find myself surrounded by men who believe that they can do certain things--make rain, send telegraphic messages, etc.; and I am told that if certain assumptions--that there is a God, that Nature is uniform, etc.--be true, then it will be well for me to behave in a certain way. But what if the assumptions be not true? My elders tell me that experience--in the individual, in the race, enlarged by science and the theory of evolution--shows it is quite safe to assume that they are true, at any rate as a provisional hypothesis. Of course, if the future is going to resemble the past, then experience of the past is a good guide to the future: but that is just the question, _is_ the future going to resemble the past? In other words, what attitude am I to assume towards my environment, the cosmos? Am I to assume that it will work, and for countless ages has worked, in such a way as to make it possible for me, with some co-operation on my part, to do things which my elders tell me are desirable and which I feel for myself I should rather like to do? If I assume that the cosmic power does work thus, in such a way that I can know the truth and do the right, and love the Power that gives me the chance and makes it possible, even for me, so to do, I am only exercising the will to believe in that principle which is logically implied by every act of the scientific or moral life. It is the common faith of mankind that experience may be trusted; and it is the common experience of mankind that progress is approximation to the ideals of truth, of goodness, and of love. It is not the common experience of mankind that all men or all peoples approximate equally to those ideals. The measure of progress is to be found in the clearness and consistency with which men have carried out in science the principle of the uniformity of Nature, in their dealings with their fellow-men the principles of morality, in their dealings with the supernatural the principle of love.