We shall best arrive at an adequate estimate of Mr. Spencer's ethical system by studying first what he terms the biological view of ethics. But to do this properly requires a survey not only of Chapter VI., which bears this title, but also of the following chapter, which deals with the psychological view. We hold that Mr. Spencer, in this division of his subject into separate stages, makes a false arrangement of his studies. For as on the one hand he endeavours to include the study of biology as a branch of physics, on the other hand he treats it as incapable of comprehensive developmental study apart from the factors of feeling and mind. These divisions are marked features of the form into which Mr. Spencer has thrown his study of human conduct, but they do not correspond with his actual treatment of the subject. The course of thought cannot be fitted into the formal outline. It is found that the understanding of biology is as dependent upon a knowledge of psychology as it is upon a knowledge of physics. The sequence of dependent stages as set forth does not hold good. The conduct of animal and perhaps vegetable organisms is not explicable as the action of mere physical aggregates, and is little understood without the admission of a subjective factor of feeling or mind. It is all very well for Mr. Spencer to argue, as he does in Chapter V., on the "Physical View," that since all conduct is objectively physical action it may be separately studied from the physical point of view; but since the actions of organisms are not to be explained within the limits of physical laws this is a very useless reminder, and Mr. Spencer himself makes nothing of the study since he cannot work out the line of causation in terms of the physical factors only. On the other hand we find that our author has not proceeded three pages into the biological view before he introduces the subjective factors of Pleasure and Pain, which he eventually establishes not merely as the accompaniments of life-sustaining and life-diminishing acts, but even as the causes of further actions which shall at the same time tend to secure Pleasure and avoid Pain, and thus sustain the organism in a continuance of existence. Only for three pages can the purely biological view of animal organisms as physical moving equilibria be maintained; and then with section 32 comes the introduction of subjective factors--factors which are treated not merely as the concomitants of physical processes conducted wholly within and according to the laws of physical sequence, but as actual factors interfering with and affecting the line of causation. It is true Mr. Spencer recognises and deals with the difficulty which obviously arises as to the separability of the psychological view from a biological view which admits the factors of Pleasure and Pain. But the distinction he makes, while justifiable, does not deal with the fundamental difficulty.