But the word mind calls up before us a long list of powers.  And the questions arise, Is one mode and line of mental action just as much the goal of man’s development as another?  Is man to cultivate the appetite for food and sense gratification just as much as the hunger for righteousness?  Or is appetite in the mind like digestion in the body, a function, necessary indeed and once dominant, but no longer fitted for supreme control?  Is there in the development of the mental powers or functions just as really a sequence of dominance as in that of the bodily functions?  Are there older and lower powers and modes of action, which, though once supreme, must now be rigidly kept down in their proper lower place?  Are there lower motives, for which the very laws of evolution forbid us to live, just as truly as they forbid a man’s living for stomach or brute strength instead of brain and mind?  Are these lower powers merely the foundation on which the higher motives and powers are to rise in their transcendent glory?  This is the question which we now must face, and it is of vital importance.

We have come to one of the most important and difficult subjects of zooelogy.  Let us distinctly recognize that it is not our task to explain the origin of mind, or even of a single mental faculty.  I shall take for granted what many of you will not admit, that the germs of all man’s highest mental powers are present undeveloped in the mind, if you will call it so, of the amoeba.  The limits of this course of lectures have required us to choose between alternatives, either to attempt to prove the truth of the theory of evolution, or taking this for granted, to attempt to find its bearings on our moral and religious beliefs.  I have chosen the latter course, and here, as elsewhere, will abide by it.  I should not have followed such a course if I did not thoroughly believe that man also, in mind as well as body, is the product of evolution.  But this is no reason for your accepting these views.  You are asked only to judge impartially of the tendencies of the theory.  We take for granted, I repeat, that all man’s mental faculties are germinally, potentially, present in protoplasm; we seek the history of their development.

We must remember, further, that the science of animal or comparative psychology is yet in its infancy.  Even reliable facts are only slowly being sifted and recorded in sufficient numbers to make deductions at all safe.  And even of these facts different writers give very different explanations.  As Mr. Romanes has well said, “All our knowledge of mental faculties, other than our own, really consists of an inferential interpretation of bodily activities—­this interpretation being founded on our subjective knowledge of our own mental activities.  By inference we project, as it were, the human pattern of our own mental chromograph on what is to us the otherwise blank screen of another mind.”  The value and clearness of our inferences will be proportional