1850. Social Statics: especially chapter General Considerations. (Higher human Evolution.) 1852. March. Development Hypothesis, in the Leader. (Evolution of species, _vid. ante_, p. 111.) 1852. April. Theory of Population, etc., in Westminster Review. (Higher human Evolution.) 1854. July. The Genesis of Science in British Quarterly Review. (Intellectual Evolution.) 1855. July. Principles of Psychology. (Mental Evolution in general.) 1857. April. Progress: its Law and Cause: Westminster Review. (Evolution at large.) 1857. April. Ultimate Laws of Physiology. National Review. (Another factor of Evolution at large.) "From these last two Essays came the inception of the Synthetic Philosophy. The first programme of it was drawn up in January, 1858." ... When seeing Mr. Spencer on the subject of this letter, he took the further trouble to point out certain passages in the essays originally comprised in the one volume edition of 1858 which contain germinal ideas of his synthesis. That they are his selection will add to the interest and value of their quotation, revealing, as perchance they may, a fragment of the autobiography which it is an open secret Mr. Spencer has written. "That Law, Religion, and Manners are thus related--that their respective kinds of operation come under one generalisation--that they have in certain contrasted characteristics of men a common support and a common danger--will, however, be most clearly seen on discovering that they have a common origin. Little as from present appearances we should suppose it, we shall yet find that at first, the control of religion, the control of laws, and the control of manners, were all one control. However incredible it may now seem, we believe it to be demonstrable that the rules of etiquette, the provisions of the statute-book, and the commands of the decalogue, have grown from the same root. If we go far back enough into the ages of primeval Fetishism, it becomes manifest that originally Deity, Chief, and Master of the Ceremonies were identical" (Essays, vol. i, 1883 edition; Manners and Fashion, p. 65). "Scientific advance is as much from the special to the general as from the general to the special. Quite in harmony with this we find to be the admissions that the sciences are as branches of one trunk, and that they were at first cultivated simultaneously; and this becomes the more marked on finding, as we have done, not only that the sciences have a common root, but that science in general has a common root with language, classification, reasoning, art; that throughout civilisation these have advanced together, acting and reacting on each other just as the separate sciences have done; and that thus the development of intelligence in all its divisions and subdivisions has conformed to this same law to which we have shown the sciences conform" (Ib. The Genesis of Science, pp. 191, 192).