The entire significance of the evolutionary method in biology and social history is that every distinct organ, structure, or formation, every grouping of cells or elements, has to be treated as an instrument of adjustment or adaptation to a particular environing situation. Its meaning, its character, its value, is known when, and only when, it is considered as an arrangement for meeting the conditions involved in some specific situation. This analysis of value is carried out in detail by tracing successive stages of development--by endeavoring to locate the particular situation in which each structure has its origin, and by tracing the successive modifications through which, in response to changing media, it has reached its present conformation.[3] To persist in condemning natural history from the standpoint of what natural history meant before it identified itself with an evolutionary process is not so much to exclude the natural-history standpoint from philosophic consideration as it is to evince ignorance of what it signifies. Psychology as the natural history of the various attitudes and structures through which experiencing passes, as an account of the conditions under which this or that state emerges, and of the way in which it influences, by stimulation or inhibition, production of other states or conformations of consciousness, is indispensable to logical evaluation, the moment we treat logical theory as an account of thinking as a mode of adaptation to its own generating conditions, and judge its validity by reference to its efficiency in meeting its problems. The historical point of view describes the sequence; the normative follows the sequence to its conclusion, and then turns back and judges each historical step by viewing it in reference to its own outcome.[4] In the course of changing experience we keep our balance as we move from situations of an affectional quality to those which are practical or appreciative or reflective, because we bear constantly in mind the context in which any particular distinction presents itself. As we submit each characteristic function and situation of experience to our gaze, we find it has a dual aspect. Wherever there is striving there are obstacles; wherever there is affection there are persons who are attached; wherever there is doing there is accomplishment; wherever there is appreciation there is value; wherever there is thinking there is material-in-question. We keep our footing as we move from one attitude to another, from one characteristic quality to another, because we know the position occupied in the whole growth by the particular function in which we are engaged, and the position within the function of the particular element that engages us.