damental connecting link is to be found between the work in its totality and the other divisions of the Synthetic Philosophy.
One large aspect of universal evolution remains to be considered before the organization of knowledge demanded by philosophy can be taken as complete; and this aspect—of such importance as to lead Mr. Spencer to describe all other parts of his work as subsidiary to its interpretation[1]—we at length reach in the concluding two volumes of the series comprising The Principles of Ethics. To the student of the earlier divisions of the Spencerian system the point of view adopted in the elucidation of the facts and problems of conduct will appear a matter of course. Ethics necessarily depends upon the simpler sciences, and generalizations furnished by these must be accepted as data for the systematization of the principles of right living. Moreover, conduct at large, including those portions of it which form the subject-matter of morality, can be fully understood only when regarded as one phase of evolving life. This conception of things will now seem so natural as to call for nothing beyond the baldest statement.
In his work of reconstructing ethical theory along the lines thus indicated, and in harmony with the fundamental doctrines of his philosophy, Mr. Spencer takes a great and most important step in advance of the results reached by the various schools of scientific moralists in the past. His system is, of course, hedonistic or utilitarian—that is, the final criterion and ultimate end of conduct is for him happiness, pleasure, or well-being. But he was naturally discontent with the merely empirical conclusions in which the older utilitarians had been willing to rest. They had not pushed beyond the inductive stage of inquiry; and their generalizations, however interesting and valuable they might be, were merely generalizations after all—statements founded simply upon accumulated observations of results. But, though every science begins with such observations and generalizations, it has no claim to be considered a developed science until the principle
of causation is fully recognized and inductive results are set forth in deductive form. It is the scientific presentation of ethical principles, in this strict sense of the word scientific, that Mr. Spencer has, therefore, undertaken. He has sought to convert the laws of conduct from truths of the empirical into truths of the rational order. As he wrote in his letter to Mill:[2] "I conceive it to be the business of moral science to deduce from the laws of life and the conditions of existence what kinds of action necessarily tend to produce happiness and what kinds to produce
