I adduce these considerations not merely to suggest a possibility which is hardly more than a guess. It seems to be unthinkable that it is not the case that many more people than actual geniuses have some trace of genius. The quantitative difference in natural endowment will be most marked at the moment when the endowment becomes active. And for most men this moment is the point of death. If we were not accustomed to regard men of genius as a separate class shut off from the others like the payers of income-tax, we should find less difficulty in grafting these new ideas on the old. And just as the earliest recollections of childhood which a man has are not the result of some external event breaking through the continuity of the past course of his life, but are the result of his internal development, there comes to every one a day on which his consciousness is so intensified that remembrance remains, and from that time onwards, according to his endowment, more or fewer remembrances are formed (a factor which by itself upsets the whole of modern psychology), so in different men there are many different stimulants of the consciousness of which the last is the hour of death, and from the point of view of their degree of genius men might almost be classified by the number of things that excite their consciousness. I take this opportunity of again urging the falseness of a doctrine of modern psychology (which treats men simply as better or worse pieces of registering apparatus and takes no notice of the internal, ontogenetic development of the mind); I mean the idea that in youth we retain the greatest number of impressions. We must not confuse really experienced impressions with the mere material on which to exercise memorising. Such stuff a child learns more easily simply because it is not weighted with mental impressions. A psychology which is opposed to experience in matters so fundamental must be rejected. What I am attempting at present is no more than to give the faintest indication of that ontogenetic psychology or theoretical biography which sooner or later will replace what now passes for the science of mind. Every programme represents some definite conviction; before we wish to reach a goal we have some definite conception of what the goal is to be. The name “theoretical biography” will define the new subject from philosophy and physiology, and the biological method of treatment introduced by Darwin, Spencer, and others will be widened until it becomes a science capable of giving a rational orderly account of the whole course of the mental life from the cradle to the grave. It is to be called biography, not biology, because it is to deal with the investigation of the permanent laws that rule the mental development of an individual, whereas biology itself concerns itself with individuals themselves. The new knowledge will seek general points of view and the establishment of types. Psychology must try to become theoretical biography. Existing psychology would find its place in the branches of the new science, and in this way only would Wundt’s desire to establish the foundations of a science of the mind be fulfilled. It would be absurd to despair of this simply because of the uselessness of the existing science of the mind which has not yet even grasped its own object. In this way a justification for experimental psychology might yet be found, in spite of the important results of the investigations by Windelband and Rickert on the relation between natural and psychical science, or the old dichotomy between the physical and mental sciences.