work, which would leave him leisure enough for the execution of his scheme. Mr. Mill replied sympathetically, but nothing turned out to be available. In despair of any other possibility, Mr. Spencer afterward extended his application to the Government; being reënforced by the influence of various leading scientific men, who expressed themselves strongly respecting the importance of giving him the opportunity he wished. A peculiar difficulty, however, here arose. Mr. Spencer is a very impracticable man—that is, he undertakes to conform his conduct to right principles, and his decided views as to the proper functions of government put an interdict upon the far greater number of posts that might otherwise be fit. Among the few that he could accept, the greater part were not available because they did not offer the requisite leisure. One position became vacant which he might have accepted, that of Inspector of Prisons, I think; but, though effort in his behalf was made by Lord Stanley (now Lord Derby, who was familiar with Mr. Spencer's works and entertained the matter with interest), the claims of party were too strong, and no arrangement was made.
Other plans failing, Mr. Spencer decided to adopt the plan of subscription, and issue his "System of Philosophy" in a serial form. A prospectus of that system was issued in March, 1860, which outlined the contents of the successive parts. The first installment of the work was issued in October, 1860, and the commencing volume, "First Principles," was published in June, 1862.
In this work the general doctrine of Evolution is presented in a greatly developed form; and the author's former views are not only combined but extended. The law of Von Baer, which formulates organic development as a transformation of the homogeneous into the heterogeneous, Mr. Spencer had previously shown to hold of all aggregates whatever—of the universe as a whole and of all its component parts. But, in "First Principles," it was shown that this universal transformation is a change from indefinite homogeneity to definite heterogeneity; and it is pointed out that only when the increasing multiformity is joined with increasing definiteness, does it constitute Evolution as distinguished from other changes that are like it in respect of increasing heterogeneity. This is, however, a much more important development of the principle. This change from the indefinite to the definite is shown to be the accompaniment of a more essential change from the incoherent to the coherent. Throughout all aggregates of all orders it is proved that there goes on a process of integration. This process is shown to hold alike in the growth and consolidation of each aggregate as well as in the growth and consolidation of its differentiated parts. The law of the instability of the homogeneous is also more elaborately traced out. Under the head of the principle of segregation it is, moreover, shown that the universal process by which, in aggregates of mixed units, the