_The preceding pages originally formed the second portion of a_ _pamphlet entitled_ The Classification of the Sciences: to which are added Reasons for dissenting from the Philosophy of M. Comte, _which was first published in 1864. For some time past this pamphlet has been included in the third volume of my_ Essays, &c., _and has been no longer accessible in a separate form. There has recently been diffused afresh, the misconception which originally led me to exhibit my entire rejection of those views of M. Comte, which essentially distinguish his system from other systems; and the motives which then prompted me to publish the reasons for this rejection, now prompt me to put them within the reach of all who care to inquire about the matter. The Appendix, presenting an outline of the leading propositions of the Synthetic Philosophy, will further aid the reader in forming a correct judgment_. _Oct. 7, 1884._ APPENDIX A. Some fourteen or more years ago, an American friend requested me, with a view to a certain use which he named, to furnish him with a succinct statement of the cardinal principles developed in the successive works I had published and in those I was intending to publish. This statement I here reproduce. Having been written solely for an expository purpose, and without thought of M. Comte and his system, it will serve better than a statement now drawn up since it is not open to the suspicion of being adapted to the occasion.[22] “1. Throughout the universe in general and in detail, there is an unceasing redistribution of matter and motion. “2. This redistribution constitutes evolution where there is a {141} predominant integration of matter and dissipation of motion, and constitutes dissolution where there is a predominant absorption of motion and disintegration of matter. “3. Evolution is simple when the process of integration, or the formation of a coherent aggregate, proceeds uncomplicated by other processes. “4. Evolution is compound when, along with this primary change from an incoherent to a coherent state, there go on secondary changes due to differences in the circumstances of the different parts of the aggregate. “5. These secondary changes constitute a transformation of the homogeneous into the heterogeneous—a transformation which, like the first, is exhibited in the universe as a whole and in all (or nearly all) its details: in the aggregate of stars and nebulae; in the planetary system; in the earth as an inorganic mass; in each organism, vegetal or animal (Von Baer’s law); in the aggregate of organisms throughout geologic time; in the mind; in society; in all products of social activity.