"Without reason, as without memory, there might still be pleasures and pains in existence. To increase those pleasures and reduce those pains would be to introduce an improvement into the sentient world, as if a devil suddenly died in hell or in heaven a new angel were created. Since the beings, however, in which these values would reside, would, by hypothesis, know nothing of one another, and since the betterment would take place unprayed-for and unnoticed, it could hardly be called a progress; and certainly not a progress in man, since man, without the ideal continuity given by memory and reason, would have no moral being. In human progress, therefore, reason is not a casual instrument, having its sole value in its service to sense; such a betterment in sentience would not be progress unless it were a progress in reason, and the increasing pleasure revealed some object that could please; for without a picture of the situation from which a heightened vitality might flow, the improvement could be neither remembered nor measured nor desired."[9] Carrying thus the conception and measure of progress in his own career, man can judge his history morally, and decide what progress he has made. He speaks aptly of "making" progress, recognizing in that expression that he uses the materials at his command for the ends he desires. But the materials at his command are not of his own making. He may, indeed, have modified them by former use, but in each instance of his using them they are always so much matter with a structure and character of their own. This fact puts the continuity of history in a new light. It forbids the attempt to conceive it as a movement pushing forward, as it were, into the future. We should conceive it rather from the point of view of the time process as we have already analyzed it. Then we should see that the continuity of history is the continuity of the results of the conversion of the possible into the actual--the part of the line which has been drawn. It comprises all that has been accomplished, conserved either by man's memory or by nature at large, and existing for continued modification or use. As such, it has its own structure, its own uniformities, and its own laws. To them every modification made is subject. That is why everything "connects on from what lies at hand," and why everything we do--even the expressions we use--points backward to what our ancestors have done. Since what they have done is only material for what we may do, it can not of itself explain our use of it, or judge our own values. An understanding of it should, however, make us wiser in the use of it. That is why we need contemporaneous experience and empirical science. We need to discover, either by our own experience or by reconstituting the experience of others, what happens when given material is used in a given way. Such discoveries are the only genuine explanations. They reveal the conditions to which actions must conform