various great human interests have been selected as points of departure. I have sought to introduce the general stand-point and problem of philosophy through its implication in practical life, poetry, religion, and science. But in so doing it has been necessary for me to deal shortly with topics of great independent importance, and so risk the disfavor of those better skilled in these several matters. This is evidently true of the chapter which deals with natural science. But the problem which I there faced differed radically from those of the foregoing chapters, and the method of treatment is correspondingly different. In the case of natural science one has to deal with a body of knowledge which is frequently regarded as the only knowledge. To write a chapter about science from a philosophical stand-point is, in the present state of opinion, to undertake a polemic against exclusive naturalism, an attitude which is itself philosophical, and as such is well known in the history of philosophy as _positivism_ or _agnosticism_. I have avoided the polemical spirit and method so far as possible, but have, nevertheless, here taken sides against a definite philosophical position. This chapter, together with the Conclusion, is therefore an exception to the purely introductory and expository representation which I have, on the whole, sought to give. The relatively great space accorded to the discussion of religion is, in my own belief, fair to the general interest in this topic, and to the intrinsic significance of its relation to philosophy. I have in Part II undertaken to furnish the reader with a map of the country to which he has been led. To this end I have attempted a brief survey of the entire programme of philosophy. An accurate and full account of philosophical terms can be found in such books as Külpe's "Introduction to Philosophy" and Baldwin's "Dictionary of Philosophy," and an attempt to emulate their thoroughness would be superfluous, even if it were conformable to the general spirit of this book. The scope of Part II is due in part to a desire for brevity, but chiefly to the hope of furnishing an epitome that shall follow the course of the _natural and historical differentiation_ of the general philosophical problem. Finally, I have in Part III sought to present the tradition of philosophy in the form of general types. My purpose in undertaking so difficult a task is to acquaint the reader with philosophy in the concrete; to show how certain underlying principles may determine the whole circle of philosophical ideas, and give them unity and distinctive flavor. Part II offers a general classification of philosophical problems and conceptions independently of any special point of view. But I have in Part III sought to emphasize the point of view, or the internal consistency that makes a _system of philosophy_ out of certain answers to the special problems of philosophy. In such a division into types, lines are of necessity drawn too sharply. There will be many historical philosophies that refuse to fit, and many possibilities unprovided for. I must leave it to the individual reader to overcome this abstractness through his own reflection upon the intermediate and variant stand-points. Although the order is on the whole that of progressive complexity, I have sought to treat each chapter with independence enough to make it possible for it to be read separately; and I have provided a carefully selected bibliography in the hope that this book may serve as a stimulus and guide to the reading of other books. The earlier chapters have already appeared as articles: Chapter I in...