But by the ‘ethics of evolution’ is meant something more than the ‘evolution of ethics’ or development of morality.  It signifies a theory which turns the facts of evolution to account in determining the value for man of different kinds of conduct and feeling and idea.  When one speaks of the ethics of evolution one must be understood to mean that the evolution theory does something more than trace the history of things, that it gives us somehow or other a standard or criterion of moral worth or value.  This additional point may be expressed by the technical distinction between origin and validity.  Clearly there is a very great difference between showing how something has come to be what it is and assigning to it worth or validity for the guidance of life or thought It may be that the former enquiry has some bearing upon the latter; but only confusion will result if the two problems are not clearly distinguished at the outset,—­as they very seldom are distinguished by writers on the theory of evolution in its application to ethics.

It may be said that the evolutionist writers on ethics seek to base an ethics of evolution upon the evolution of ethics, but that they are not always aware of the real nature and difficulties of their task.  Sometimes they seem to think that in tracing the evolution of ethics they are also and at the same time determining and establishing a theory of the ethics of evolution.  We must avoid this error, and keep the two problems distinct in our minds.  Yet from the nature of the case it holds true that it is only through the facts which the theory of evolution establishes or can establish as to the development of morality that it is able to make any contribution to the solution of the further question as to the criterion of morality—­the question, that is to say, of moral worth or value.

We cannot, therefore, avoid dealing with the evolution of ethics.  But in what follows I am not considering it for its own sake—­though it is an interesting and important question.  In order to simplify the argument, we may allow what is claimed for it, and give the evolutionist credit for even greater success on the field of historical investigation—­which is his own field—­than he would, if fair-minded, claim for himself.  The problem I have in view lies beyond this historical question.  It is the problem how far the known facts and probable theories regarding the development of morality can make any contribution towards determining the standard of worth for our ideas, our sentiments, and our conduct.  Now if we read the accredited exponents of the doctrine of evolution we shall find amongst them a considerable variety of view regarding the bearing of the theory of evolution upon this properly ethical problem—­the problem of the criterion or standard of goodness.