The difficulty which philosophy has always found in giving a strictly scientific definition of itself, or even in describing at all conclusively the sphere within which it proposes to limit its activities, has often been made a serious charge against its usefulness. A certain vagueness and vacillation in fixing the aim of philosophizing is, of necessity, connected with this difficulty in defining the content of the conception of philosophy. Thus when both the vulgar crowd and the thoughtful few have received uncertain or mystical answers to the two related questions: What are you? and What can you do for us, or what benefits confer upon us? they have not at all unnaturally, and not altogether unreasonably, turned their backs upon this appli- cant for their attention and their favor.

To define philosophy has for several centuries been a problem which its students have thought themselves called upon to solve, at least in some preliminary fashion, before beginning the serious and systematic discussion of the particular problems which the very definition makes it proper to include within its legitimate province. But they have not, as a rule, been so much concerned with the discussion of the question which requires that philos- ophy should vindicate its right to realize progressively - its self-appointed tasks. They have had little success in showing how their attempts, whether attended with more or less of success or even of failure, have a real and important value for the life of humanity.