EVOLUTION 765 ence from the lowest to the highest. He excludes all con sideration of the question how life first arose, though it is clear that he regards the lowest forms of life as continuous in their essential nature with sub-vital processes. It is in the later volumes, dealing with mental and social evolu tion, that Mr Spencer s exposition becomes most interest ing to the student of philosophy. In the Principles of Psychology, he seeks to deal wit.h mind as an aspect or correlate of life which begins to manifest itself when the process of adjustment to environment, in which all life consists, reaches a certain degree of complexity. Mr Spencer indulges in no hypothesis respecting the universal co-existence of sentience with matter and force. He thinks we must accept the distinctions which common-sense has established, and so limit feeling or consciousness to organic beings endowed with a nervous system. Thus, just as he does not seek to explain the first appearance of life as a whole, so he does not seek to explain the first dawn of mental life. Mr Spencer s unit of consciousness is the blurred undetermined feeling which answers to a single nervous pulsation or shock. Assuming this he seeks to trace the gradual evolution of consciousness. Sensations aris3 by a number of rapid successions of such elementary feelings variously combined, and all more composite states of mind arise by a similar process of combination of these feelings. Thus mental evolution is a progressive composi tion of units of feeling in more and more complex; forms, and united by more complex relations. Mr Spencer s con ception of mind thus excludes all fundamental distinctions of faculty. Instinct, memory, reason, the emotions and volitions, alike develop themselves in divergent directions out of a common elementary process. They are, moreover, all related to one and the same biological process, being incidental accompaniments of the actions by which the organism responds and adjusts itself to the forces of its environment. According as these actions are more complex, and consequently less immediate, the mental actions which accompany them vary in character from reflex action up to deliberate volition, from the most simple presentative feeling or sensation up to the most complex representative and re-representative feeling or emotion. It would be im possible to point to all the applications which Mr Spencer has made of his principle of evolution to the questions of psychology. We may just mention among other points of interest his attempt to explain the innate intuitions of space, moral right, &c., as mental dispositions handed down from progenitors and embodying the uniform expe rience of many generations, his ingenious endeavour to account for the coincidence between pleasures and pains and actions beneficial and injurious to the organism, and his Conception of the aesthetic interest as a growth out of the play-impulse, which is the tendency of activities that have become developed beyond the immediate needs of existence to vent themselves. Mr Spencer s elaboration of the subject of social evolu tion has not been carried far enough for us to understand the full bearing of his ideas. Yet the fundamental con ceptions are given us. The writer regards society, after the analogy of an individual organism, as possessing a number of various structures or organs and functions, and as tending to evolve itself by a series of adjustments to its environment, physical and social. All ideas and institutions display this process of evolution no less than societies as wholes. History is to our author essentially the record of this social evolution. It is to be observed that Mr Spencer attributes to society a certain sponta neous tendency to evolution apart from natural selec tion. He looks on progress as a gradual process of self- adaptation of man to the conditions of his environment, and anticipates an age when this adjustment will be com plete and human happiness perfect. In this respect Mr Spencer s conception of man s history and destiny wears an optimistic tinge when compared with that very vaguely shadowed forth by Mr Darwin. To Mr Spencer, as to Mr Darwin, the doctrine of evolu tion seems to supply the end of conduct. He conceives of morality as essentially an observance of the laws of life, the individual and the collective. At the same time, since Mr Spencer regards the moral sense as a growth out of feelings of pleasure and pain (racial experiences), closely identifies the ends of life and happiness, and distinctly teaches that social evolution or progress makes for an increase of happi ness, his ethical doctrine does not materially differ from that of utilitarianism. So far we have said nothing respecting the metaphysical basis which Mr Spencer seeks to give to his doctrine of evolution. It is generally agreed that this does not really belong to his doctrine of evolution itself. Mr Spencer is a thorough-going realist. From his general scheme of evolution one would be prepared to find him avowing himself a materalist. Yet he seeks to avoid this con clusion by saying that it is one unknowable reality which manifests itself alike in the material and in the men tal domain. At the same time, this unknowable is com monly spoken of as force, and in many places seems to be identified with material force. Mr Spencer makes little use of his metaphysical conception in accounting for the evolu tion of things. He tells us neither why the unknowable should manifest itself in time at all, nor why it should appear as a material world before it appears under the form of mind or consciousness. Indeed Mr Spencer s doctrine of evolution cannot be said to have received from its author an adequate metaphysical interpretation. The idea of the unknowable hardly suffices to give to his system an intelli gible monistic basis. In truth, this system seems in its essence to be dualistic rather than monistic. Metaphysical Interpretation Professor Clifford. Of the very few who have dealt with the metaphysical interpreta tion of the scientific doctrine of evolution, Professor Clifford deserves special notice. In an essay entitled " On things in themselves, " published in Mind (No. ix.), as well as in other and earlier papers, Mr Clifford, starting from the basis of empirical idealism which asserts that material objects are nothing but states of consciousness, argues that the reality answering to them is in all cases something mental. Thus all existence including what we call minds as well as bodies consists in aggregates of elementary " mind stuff," the elements themselves corresponding to Mr Spencer s units of feeling. The writer expressly argues that his idea of a continuity of mental existence through out the physical (phenomenal) world is the direct conse quence of the doctrine of evolution. This theory is curious as providing a monistic and quasi-spiritualistic conception of evolution, which is at the same time a mechanical one. Problems of Organic Evolution. G. II. Lewes. Among the writers who have worked on the lines laid down by our two great evolutionists, a high place must be given to Mr G. II. Lewes, who in his biological and psycho logical writings, and more especially the Problems of Life and Mind, adopts a view of the relations of mind and life or organization closely resembling in its essentials that of Mr Spencer. To Mr Lewes consciousness is but a more complex form of mental life which is correlated with the actions of all the nervous centres, its lowest form being sentience. He appears to look on mind in all its grades as but the other side or face of the bodily processes which it accompanies. Yet he has not so far made use of this monistic conception in explaining the gradual evolution of conscious mental life. Indeed, though Mr Lewes s writings
are pervaded with the idea of organic evolution, his dis-