original simplicity of motive has been broken into, and something else than personal pleasure admitted to have sway. But it does not seem to have been made out that action in the early stages of human life was completely egoistic, any more than that it is so now. "From first to last," as Mr Spencer puts it,[133] self-sacrifice seems to have been involved in the preservation of each successive generation of individuals. We inherit propensities to action which have been evolved from an initial stage in which there was no conscious distinction between egoism and altruism, though both tendencies were present and were necessary for the continued existence of the species. The feelings inherited by the egoistic hedonist are assessed by him at their pleasure-value. But such feelings would never have been acquired by his ancestors, had they tested each germinal emotion in the same way, and so restrained self-sacrifice for offspring and fellow-men. Perhaps they did not clearly see or realise what their pleasure consisted in, or accurately distinguish it from family or tribal welfare; but, through this deficiency of imagination, the feelings were able to grow and perpetuate themselves, which have tended to the preservation and consolidation of society. [Sidenote: nor of ethical hedonism.] Nor can we gather from evolution any ethical argument leading to egoism as the principle or end for conduct; and it is worthy of remark that the proof attempted by the late Mr Barratt is unaffected by his recognition of the theory of evolution as applied to mind, depending on definitions and axioms which hold (if at all) for the individual man. Pleasure is defined by him as "that state of consciousness which follows upon the unimpeded performance (as such) of its function by one or more of the parts of our organism;"[134] and the good is forthwith identified with pleasure, by its being shown that it is a "state of consciousness," and that it "results from the due performance of function (as such)."[135] But the "due[136] performance of function" is itself a state or states of consciousness; and in it, not in any sequent or concomitant circumstances, the good may consist. The good, we may say, is not pleasure, but the ἐνέργεια (~energeia~) of which pleasure is only the consequent or completion. This is not a mere question of words. For "due performance of function" cannot be measured by the resultant or accompanying feeling of pleasure: the most perfect functioning, just because it has become habitual, has often the slightest accompaniment of pleasant feeling. The way in which the argument is put in 'Physical Ethics' is thus well fitted to bring out the fundamental antithesis between ethical systems according as they place the good in the active element of function, or in the passive element of pleasurable feeling which accompanies functioning. The theory of evolution seems to have led many of the writers who have