This work does not profess to be a treatise on the subject of feeling, but merely a series of studies, and rather tentative ones at that. I have attempted to deduce from the standpoint of biologic evolution the origin and development of feeling, and then to consider how far introspection confirms these results. I am well aware that I traverse moot points—what points in psychology are not moot?—and I trust that the position taken will receive thorough criticism. I should be very glad to have new facts adduced, whatever way they may bear. I have no theory to defend, but the results offered are simply the best interpretation I have as yet been able to attain.