more general bearings of the relation, and at any rate its discussion may serve to break the ground in such a way as to suit it for our future more detailed operations. In considering this subject, what I wish to bring before you is this: that ethics must always have their roots in psychology; that as our psychology is, so must our ethics be (that is, if we preserve any consistency in our reasoning); that a confused or imperfect or erroneous psychology must always issue in a confused or imperfect or erroneous moral theory; and that a correct moral theory is only to be reached through a correct psychological system.
2. To trace this connection, I must first of all speak of psychology, and of the principal problem with which psychology has to deal. The main problem of psychology is that concerning the nature and origin of our knowledge. More explicitly stated, the question is this: What cognitions or elements of cognition are native to the mind itself, and what cognitions or elements of cognition are imparted to it from without? Or stated perhaps still more distinctly, it is this: In the formation of our knowledge, that is, in our apprehensions of the things around us, what ingredients belong to, and are supplied by, the mind, and what ingredients are contributed by foreign and external causes?
3. Now, two very extreme answers, two answers widely opposed to each other, may be conceived to
