Idealism holds, speaking more positively, that philosophers must submit the conceptions and methods which they employ to a preliminary immanent criticism, in order to determine the limits within which they may be validly applied. Every genuine category or method is valid within a certain sphere of relevance, and the business of criticism is to determine by empirical investigation or by 'ideal experiment' (which means much the same thing) what concrete significance the conception is capable of bearing. Dewey, from the standpoint of idealism, is guilty of a somewhat uncritical use of the categories of 'description' and 'evolution.' Are the categories of biology fitted to explain mind and spirit? Instead of instituting an inquiry designed to answer that question, Dewey accepts 'evolutionism' as final, and attempts to force all phenomena into conformity with his resulting logical scheme. He misses the valuable checks upon thought which are furnished by the 'critical method,' and is none too sensitive to the technical results of the special sciences. The logical approach to philosophy strictly involves certain implications which have been overlooked by many of its critics. It may well be admitted that our real categories are not fixed and final, but are perpetually in process of reconstruction. The process of criticism inevitably makes manifest the human and empirical character of the particular forms of reflective thought. It recognizes the fact of development, both in knowledge and in reality, and by this very recognition the value of knowledge is enhanced. It is forced, by the very nature of its method, to recognize the concrete and practical bearings of thought. Indeed, there is a sense in which idealism would declare that there is no thought--when thought, that is, is taken to mean an isolated fact out of relation to the world. It is not possible to make this retort upon the critics of idealism without recognizing that there has been a vast misjudgment, amounting almost to misrepresentation, of the intellectual ideals of modern speculative philosophy.