Still another view is possible. It may be held that the morality of self-restraint and self-sacrifice are opposed--as Huxley says they are opposed--to the methods of cosmic evolution; and yet the "gladiatorial theory of existence" may not be repudiated; but morality may be modified to suit the claims of evolution. This is the position adopted by the philosopher Nietzsche, whose whole thought is permeated by the idea of evolution. Like Professor Huxley, Nietzsche might say that morality is opposed to the cosmic process. But by morality he would mean something that is not to be encouraged, but that is to be shed from human life, or at least fundamentally transformed, just because it is in opposition to the laws of cosmic progress. On the other hand, the morality--if we may use the term--which the cosmic process teaches us will be a development of the conceptions of self-assertion and self-reliance, qualities which, according to ordinary morality--the morality, for instance, of Professor Huxley--require to be permeated and even superseded by self-restraint and possibly self-sacrifice in order that the moral law may be satisfied. Not obedience, not mutual help, not benevolence, but the will to rule or desire of power, is with Nietzsche fundamental, the primary impulse in the history of the whole progress of the world, and still of first importance for the further development of mankind. This view is at the opposite extreme from Huxley's, for it overlooks the advantages mankind has gained by means of the social instinct and the social solidarity which it secures. But there is a further point in Nietzsche's reflexions which is suggested by the theory of development. Natural selection is not the sole agent in the development of organic life: it cannot be too often enforced that natural selection produces nothing, that its operation is purely negative. It does not properly select at all, it only excludes. What it does is to cut off the unfit specimens of living beings which nature supplies. It would have no field of operation were it not for the variety of nature. While individuals tend to repeat the characteristics of their parents, they do not repeat them without change: the principle of heredity is counterbalanced by a principle of variety equally hard to explain. All organic life exhibits this tendency to variation; and one variation proves better adapted than another to the environment. It is this which makes possible the operation of 'natural selection.' Unfit varieties are exterminated by natural selection, and room is thus left for varieties which are fit to perpetuate themselves and to increase in efficiency. Now, if we apply this conception to human conduct, should we not encourage all varieties to carry on their experiments in living and in morality so that we may see whether success will justify them? An affirmative answer to this question is sometimes vaguely hinted at; by Nietzsche it is proclaimed from the housetops.