When we substitute for ideas as uniform rules by which to decide doubtful cases that making over of ideas which is requisite to make them fit, the quality of thought alters. We may fairly say that we have come into another stage. The idea is now regarded as essentially subject to change, as a manufactured article needing to be made ready for use. To determine the conditions of this transition lies beyond my purpose, since I have in mind only a descriptive setting forth of the periods through which, as a matter of fact, thought has passed in the development of the inquiry function, without raising the problem of its "why" and "how." At this point we shall not do more than note that, as the scheduled stock of fixed ideas grows larger, their application to specific questions becomes more difficult, prolonged, and roundabout. There has to be a definite hunting for the specific idea which is appropriate; there has to be comparison of it with other ideas. This comes to involve a certain amount of mutual compromise and modification before selection is possible. The idea thus gets somewhat shaken. It has to be made over so that it may harmonize with other ideas possessing equal worth. Often the very accumulation of fixed ideas commands this reconstruction. The dead weight of the material becomes so great that it cannot sustain itself without a readjustment of the center of gravity. Simplification and systematization are required, and these call for reflection. Critical cases come up in which the fiction of an idea or rule already in existence cannot be maintained. It is impossible to conceal that old ideas have to be radically modified before the situation can be dealt with. The friction of circumstance melts away their congealed fixity. Judgment becomes legislative.