itself in the most varied quarters, English as well as continental, among empiricists as well as transcendentalists. Strenuous attempts have been made to differentiate the various questions embraced under the general term "philosophy," and assign each as a subject of inquiry to a separate science or discipline.
In this way there has been constituted what, so far as the name goes, is a new science, though the inquiries grouped under it have formed part of philosophical investigation since a very early time. This is the science which, for the last thirty years or so, the Germans have come to call distinctively Erkenntnisstheorie, or theory of knowledge. Theory of Knowledge has been the circumlocution largely adopted by English writers who have wished to enforce the distinction between these inquiries and the investigations of psychological science. But as the distinction has come more to the front, the need of a single word has been felt, — were it only, as Hamilton pointed out in the case of psychology, that we may be able to form an adjective from it, — and accordingly just as psychology supplanted the more cumbrous designations such as science or philosophy of mind, so the excellent and in every way unobjectionable title of epistemology will, in all probability, permanently take the place of the less convenient designation "theory of knowledge."
But it will be asked what is the subject of this new science, or rather what particular philosophical inquiries are to be isolated and grouped under it? To this it may be answered generally that epistemology is an investigation of knowledge as knowledge, or, in other words, of the relation of knowledge to reality, of the validity of knowledge. This, at least, is the fundamental question to which other epistemological discussions are subsidiary. The precise bearing of this definition is best seen by a contrast between epistemology and psychology in their mode of dealing with the same subject-matter; for, in a sense, the fact of knowledge belongs to psychology as much as to epistemology. This contrast has been lucidly expounded within the last few years by several writers. But the differ-
