Herbert Spencer, an English philosopher, born in Derby, April 27,1820. His father was a teacher. Herbert was fond of keeping insects and watching their transformations, and for years the finding and rearing of caterpillars, the catching and preserving of winged insects and making drawings of them, were his regular occupations. He also assisted his father in philosophical experiments. At the age of 13 he was sent to study with his uncle, the Rev. Thomas Spencer, rector of the parish of Hinton. Here ho remained three years, and made special progress in mathematics. Returning home, ho studied perspective with his father, on the principle of independent discovery, the successive problems being put in such order that he was enabled to find out the solutions himself. This was a favorite mode of teaching with his father, who is the author of a valuable little work entitled "Invcntion-al Geometry," on this plan. At 16 Herbert devised a new and ingenious theorem in descriptive geometry, which was published with the demonstration in the "Civil Engineers' and Architects' Journal." At 17 he accepted an engagement under Charles (afterward Sir Charles) Fox as a civil engineer, and began work on the London and Birmingham railway.

In 1841 he declined a further appointment, returned home, and spent two years in mathematical and .miscellaneous studies. He made a botanical press and a herbarium, and practised drawing and modelling. All the time he had in progress some scheme of invention, improvements in watchmaking, machinery for the manufacture of type by compression of the metal instead of casting, a new form of printing press, and the application of electrotype to engraving, afterward known as the glyptograph. In the spring of 1843 he went to London in quest of literary occupation, but did not succeed, and resumed engineering. His earliest literary contributions were made to the " Civil Engineers' and Architects' Journal," the " Philosophical Magazine," the "Zoist," and the "Nonconformist." In the last named journal, in 1842, he began the publication of a series of papers on the "Proper Sphere of Government," which were issued in a pamphlet in 1843. From 1848 to 1852 he was a regular writer for the "Economist," and subsequently contributed to various reviews elaborate papers which were pervaded with the idea, since more distinctly developed, known as the doctrine of evolution. He soon became a firm believer that all organized beings have arisen by development.

In 1854 he first conceived of evolution as a universal process, and later he came to the conclusion that it must become the basis of any system of philosophy which represents and conforms to the general method of nature. In 1860 he published a prospectus of such a system, and immediately entered upon its execution. He had already collected his essays upon the scientific aspects of social questions, and had published various volumes leading up to his system. Most of these were revised and enlarged in subsequent editions to present more fully his new philosophy. The fourth division of his system, devoted to sociology, deals with the science of human society from the point of view of evolution expounded and applied to the .general phenomena of life and mind in his earlier volumes. In furtherance of this department of his work, he has for several years employed the aid of three assistants in collecting and classifying facts pertaining to all types of society, savage tribes, decayed races, and existing civilizations, which, under the title of "Descriptive Sociology," are intended to form a series of folio volumes, of which three have been published(1876). The followingis a complete list of his publications: " Social Statics, or the Conditions essential to Human Happiness specified, and the first of them developed" (London, 1850; New York, 1865); "Principles of Psychology " (London, 1855; revised ed., 2 vols., London and New York, 1870-'72); " Railway Morals and Railway Policy " (London, 1855); " Essays, Scientific, Political, and Speculative" (London, 1857; 2d series, 1863; American ed., "Illustrations of Universal Progress," New York, 1864); " Essays, Moral, Political, and AEsthetic" (New York, 1865; new and enlarged ed., 1874); "Education, Intellectual, Moral, and Physical". (London and New York, 1860); " First Principles of a System of Philosophy" (London, 1862; New York,1864); "Classification of the Sciences," to which is added "Reasons for dissenting from the Philosophy of M. Comte" (London, 1864; 3d ed., 1871); "Principlesof Biolosy" (2 vols., London, 1864; New York, 1866-'7); "Spontaneous Generation, and the Hypothesis of Physiological Units" (New York, 1870); "Recent Discussions in Science, Philosophy, and Morals," collected from English reviews (New York, 1871; 2d ed., with six additional articles, 1873); " The Study of Sociology " (London and New York, 1873); "Descriptive Sociology: Facts Classified and Arranged" (3 vols, fol, London and New York, 1873-'4); and '-The Principles of Sociology," a quarterly serial (London and New York, 1874 et seq.). In the system of philosophy series, apart from their publication as separate volumes, "First Principles," "Principles of Biology," and "Principles of Psychology " have been issued in London serially in 34 numbers; so that the sociological division begins with No. 35 under the title "The Principles of Sociology." Nos. 35-38 were published in London and New York in 1874-'5, and the whole work is expected to consist of 15 or 18 parts.