mon but the idea of evolution, with which they are all more or less imbued. In a word, we have but one other thinker with whom, in point of influence on the higher thought of this, and probably of several succeeding generations, Mr. Spencer can be classed; it does not need saying that that other is Mr. J. S. Mill.
As we cannot present such an outline of Mr. Spencer's system of psychology as would make it generally intelligible, the purpose of directing attention to the work will perhaps be best served by selecting as the subject of remark one or two points to which the presence of the controversial element may lend a special interest. After pointing out that the cardinal fact brought to light, when nervous action is looked at entirely from the objective point of view, is, that the amount and heterogeneity of motion exhibited by the various living creatures are greater or less in proportion to the development of the nervous system, Mr. Spencer comes to the vexed question of the relation between nervous phenomena and the phenomena of consciousness. This is a subject about which, in its more subtle aspects, there is much uncertainty and some confusion of thought. It may be taken as established, that every mode of consciousness is a concomitant of some nervous change. Given certain physical conditions, accompanied by a special state of consciousness, and there is every reason to believe that physical conditions in every respect identical will always be attended by a similar state of consciousness. This, and not more than this, we think, was intended by Mr. Spencer in his chapter on Æstho-physiology. Nevertheless, several able men have, it would appear, been led to suppose that he countenances a kind of materialism (not using the word to imply any thing objectionable; for why not be materialists, if materialism be truth?), which forms no part of his philosophy. To give precision and emphasis to what we say, we would take the liberty to refer to the position taken up by Dr. Bastian in his remarkably able and important work on the "Beginnings of Life." The expression that definitely raises the issue of which we wish to speak, and which at the same time fixes Dr. Bastian to a view not in harmony with the teaching of Mr. Spencer, is the following: "We have not yet been able to show that there is evolved, during brain action, an amount of heat, or other mode of physical energy, less than there would have been had not the Sensations been felt and the Thoughts thought;" but he believes that this is the case. Our present object is not so much to show that here speculation has got on the wrong track, as that, if we understand Mr. Spencer, it is not his opinion that any thing of this kind takes place; though certainly some ambiguous phrases might be held to convey this meaning. We have mentioned the significant fact that the size of the nervous system holds a pretty constant relation to the amount and heterogeneity of motion generated. The implication is, that none of the motion evolved during nervous action disappears from the object world, passes into consciousness in the same