A few words in explanation of the following essay may not be out of place. When I first wrote down the matter of the essay, some six years ago, I was dissatisfied with the metaphysical alternatives from which the student of philosophy could select. The study of the writings of Richard Avenarius heightened my dissatisfaction with previous metaphysics, and suggested to me a point of view for a fresh start. It seems to me that discontent with established and professional metaphysics has become quite general and that a fresh start is very generally desired. Well, the only sound thing to start from is actual experience, experience not viewed through the assumptions and dialect of previous systems, but taken in an absolutely empirical fashion. We must make the effort to beg as few questions as possible at the outset. If we are rigorous enough we shall discover just what questions we have to beg and why we beg them.
This return to the empirically given is the standpoint of ‘pure experience.’ ‘Pure experience’ means at present a point of view. It is premature to speak of a philosophy of ‘pure experience’; we do not yet know what such a philosophy will have to say. But there can be no question that the point of view is the right one, and it takes something of a struggle to win it. And as I came to the point of view through Avenarius, the essay includes the attempt to restate, in a relatively independent fashion, what seem to me the essentials of his doctrine.
There are not, however, as there might seem to be, two lines of effort neither united nor clearly distinguished. I think I may claim to express the views, or at least the attitude, of Avenarius all the time. An account of the philosophy of Avenarius is a difficult matter, not because the thought is obscure or hard to follow, but because it is expressed in an elaborate and novel terminology which can hardly be omitted altogether, but which, if introduced to any great extent into an exposition, certainly gets between the reader and the thought.