idea of evolution in the organic sphere—the principle of heredity. He showed that there is an element of truth in both views, and that, while on the one hand all ideas are derived from experience, it is not alone the experience of the individual, but the experience of the race and of ancestral races, by which the mental elements become organized, transmitted, and augmented in vast time, so that each individual is born with a heritage of innate and a priori aptitudes and capacities—the products of evolution. Thus the philosophical conflict of ages was harmonized in our own time, and the brilliancy of the solution is already tempting some of our ablest thinkers to venture the assertion of rival claims to the honor of having independently reached this great result. But the priority of Herbert Spencer is here impregnable, as is unreservedly conceded by the most competent authorities. We quote the last that comes to hand. Dr. Edmund Montgomery, in a masterly series of articles on "Causation and its Organic Conditions," recently contributed to "Mind," thus refers to Spencer's enunciation of the principle:
"Until quite recently I can not detect any movement in philosophy containing a germ of sufficient power to be capable of effecting by development the deliverance from the constant and almost fruitless see-sawing of the two schools. . . .
"Suddenly, however, light began to pierce the hitherto immovable darkness. It was Mr. Herbert Spencer who caught one of those rare revealing glimpses that initiate a new epoch in the history of thought. He saw that the evolution hypothesis 'furnishes a solution of the controversy between the disciples of Locke and Kant.' To us younger thinkers, into whose serious meditations Darwinism entered from the beginning as a potent solvent of many an ancient mystery, this reconciliation of transcendentalism and experientialism may have consistently presented itself as an evident corollary from the laws of heredity. But what an achievement for a solitary thinker, aided by no other light than the penetration of his own genius, before Darwinism w r as current, to discover this deeply-hidden secret of nature which with one stroke disclosed the true relation of innate and acquired faculties, an enigma over which so many generations of philosophers had pondered in vain!"
We speak far within bounds in saying that the book embodying these and kindred views, and recasting the most subtile and complex of the sciences, must be classed with the few great works of the century, the value of which, as a contribution to progressive thought, it is hard to overestimate.
Had Mr. Spencer done nothing more than to make his powerful contribution to the regeneration of mental philosophy, this capital service to the advance of thought should have been honorably signalized by the French Academy a quarter of a century ago. But this research only prepared the way for labors of greater magnitude. His system of Psychology, matured in thought in 1853, and written in 1854, shows how early and how firmly he had grasped the principle of evolution at that early time. That he should have been enchained by the new view was inevitable. The sciences were full of the raw materials of the inquiry, and evidence rapidly accumulated that a common process of unfolding transformation may be traced through all orders of phenomena. It was while writing the "Psychology" that Mr. Spencer first reached the conviction that evolution is a universal law of the course of nature. So vast and so pregnant an idea could not fail to have an all-determining influence upon his future course of thought. He saw that the scientific elucidation of this grand generalization, the discovery of the causes and conditions of the universal process, and the comprehensive application of the principle to the reor-
