The stir which this book produced, naturally brought prominently to public attention a writer heretofore not extensively read in this country, Sir William Hamilton, upon whose metaphysical teachings the lecturer avowedly based his whole scheme. The doctrines of the metaphysician were subjected to the same scrutinizing analysis, which dissolved the enunciations of the divine; and they, like these, were pronounced "wanting." This decision was not reached or expressed in any extensive and exhaustive criticism of these writers; in which the errors of their principles and the revolting nature of the results they attained, were presented; but it rather was a shoot from the spontaneous and deep-seated conviction, that the whole scheme, of both teacher and pupil, was utterly insufficient to satisfy the craving of man's highest nature. It was rejected because it _could_ not be received. Something more than a year ago, and while the American theological mind, resting in the above-stated conviction, was absorbed in the tremendous interests connected with the Great Rebellion, a new aspirant for honors appeared upon the stage. A book was published entitled "The Philosophy of Herbert Spencer: First Principles." This was announced as the foundation of a new system of Philosophy, which would command the confidence of the present, and extort the wonder of all succeeding ages. Avowing the same general principles with Mansel and Hamilton, this writer professed to have found a radical defect in their system, which being corrected, rendered that system complete and final; so that, from it as a base, he sets out to construct a new scheme of Universal Science. This man, too, has been read, not so extensively as his predecessors; because when one has seen a geometrical absurdity demonstrated, he does not care, unless from professional motives, to examine and disprove further attempts to bolster up the folly; but still so widely read, as to be generally associated with the other writers above mentioned, and, like them, rejected. Upon being examined, he is found to be a man of less scope and mental muscle than either of his teachers; yet going over the same ground and expressing the same ideas, scarcely in new language even; and it further appears that his discovery is made at the expense of his logic and consistency, and involves an unpardonable contradiction. Previous to the publication of the books just mentioned, an American writer had submitted to the world a system of thought upon the questions of which they treat, which certainly seems worthy of some notice from their authors. Yet it has received none. To introduce him we must retrace our steps for a little.