Herbert Spencer occupies a unique place in the history of human thought, because he has been the first to attempt the construction of a philosophical system in harmony with the theory of Evolution and with the results of modern science. To his contemporaries he is known almost exclusively as the author of the colossal work which he has chosen to call the "Synthetic Philosophy." Concerning his personality very little information has been published, and it is doubtful whether he will deem it worth while to leave behind him the materials for a detailed biography. About his private life we know even less than we know about that of Kant. The very few facts obtainable may be summed up in a score of sentences.

I

Herbert Spencer was born on April 27, 1820, at Derby, in England, and was an only surviving child. His father was a schoolmaster in the town named, and secretary of a philosophical society. From him the son seems to have imbibed the love of natural science and the faculty of observation conspicuous in his work. The father was particularly interested in entomology, and Spencer himself used to collect, describe, and draw insects when a boy. At the age of thirteen he was sent to study with an uncle, Rev. Thomas Spencer, a liberal clergyman and a scholar, with whom he remained three years, carrying on the study of natural history, which he had begun in childhood. He now devoted himself to mathematics, evincing a singular capacity for working out original problems. At this time, too, he became familiar with physical and chemical investigations, and already exhibited a strong tendency to experimental inquiry and original research. His aversion to linguistic studies put a university career out of the question. At the age of seventeen he entered the office of Sir Charles Fox and began work as a civil engineer, but about eight years afterward he gave up this profession, and devoted the whole of his time to scientific experiments and studies, and to contributions on philosophical questions to various periodicals. As early as 1842, in a series of letters to the Nonconformist newspaper on "The Proper Sphere of Government," he propounded a belief in human progress based on the modifiability of human nature through adaptation to its social surroundings, and he asserted the tendency of these social arrangements to assume of themselves a condition of stable equilibrium. From 1848 to 1853 he was sub-editor of the Economist newspaper, and in his first important work, "Social Statics," published in 1850, he developed the ethical and sociological ideas which had been set forth in his published letters. The truth that all organic development is a change from a state of homogeneity to a state of heterogeneity is regarded by Spencer as the organizing principle of his subsequent beliefs. It was gradually expounded and applied by him in a series of articles contributed to the "North British," the "British Quarterly," the "Westminster," and other reviews. In these essays, and especially in the volume of "Principles of Psychology," published in 1855, the doctrine of Evolution began to take definite form, and to be applied to various departments of inquiry. It was not until four years later–a fact to be carefully borne in mind by those who would estimate correctly the relation of Spencer to Darwin–that the publication of the latter's "Origin of Species" afforded a wide basis of scientific truth for what had hitherto been matter of speculation, and demonstrated the important part played by natural selection in the development of organisms. As early as March, 1860, Spencer issued a prospectus, in which he set forth the general aim and scope of a series of works which were to be issued in periodical parts, and would, collectively, constitute a system of philosophy. In 1862 appeared the "First Principles," and in 1867 the "Principles of Biology." In 1872 the "Principles of Psychology" was published; the first part of the "Principles of Ethics" in 1879; and his "Principles of Sociology" in three volumes, begun in 1876, was completed in 1896. In the preface to the third volume of the last-named work the author explains that the fourth volume originally contemplated, which was to deal with the linguistic, intellectual, moral, and aesthetic phenomena, would have to remain unwritten by reason of the author's age and infirmities. The astounding extent of Herbert Spencer's labors becomes, indeed, the more marvellous when one considers that impaired health has for many years incapacitated him for persistent application. Owing partly to his ill health, and partly to the absorbing nature of his occupation, his life has been a retired one, and in the ordinary sense of the term, uneventful. He has never married, and, although the high opinion of his writings formed by contemporaries has led to many academic honors being pressed upon him at home and abroad, these have all been declined. It only remains to mention that in 1882 he visited the United States, where the importance of his speculations had been early recognized, and that his home is now in Brighton, England.

II

In Mr. Spencer's latest book, "Facts and Comments," a little light is thrown on the author's habits, opinions, and predilections. Referring to the athleticism to which so much attention is paid just now in English and American universities, he points out how erroneous it is to identify muscular strength with constitutional strength. Not only is there error in assuming that increase of muscular power and increase of general vigor necessarily go together, but there is error in assuming that the reverse connection cannot hold. As a matter of fact, the abnormal powers acquired by gymnasts may be at the cost of constitutional deterioration. In a paper on "Party Government" the author maintains that what we boast of as political freedom consists in the ability to choose a despot, or a group of oligarchs, and, after long misbehavior has produced dissatisfaction, to choose another despot or group of oligarchs: having meanwhile been made subject to laws, some of which are repugnant. Abolish the existing conventional usages, with respect to party fealty,–let each member of parliament feel that he may express by his vote his adverse belief respecting a government measure, without endangering the government's stability,–and the whole vicious system of party government would disappear. In a paper on "Patriotism," Mr. Spencer says that to him the cry "Our country, right or wrong," seems detestable. The love of country, he adds, is not fostered in him by remembering that when, after England's Prime Minister had declared that Englishmen were bound in honor to the Khedive to reconquer the Soudan, they, after the reconquest, forthwith began to administer it in the name of the Queen and the Khedive, thereby practically annexing it; and when, after promising through the mouths of two colonial Ministers not to interfere in the internal affairs of the Transvaal, the British Government proceeded to insist on certain electoral arrangements, and made resistance the excuse for a desolating war. As to the transparent pretence that the Boers commenced the war, Mr. Spencer reminds us that in the far West of the United States, where every man carries his life in his hands and the usages of fighting are well understood, it is held that he is the real aggressor who first moves his hand toward his weapon. The application to the South African contest is obvious. In an essay on "Style," Mr. Spencer tells us that his own diction has been, from the beginning, unpremeditated. It has never occurred to him to take any author as a model. Neither has he at any time examined the writing of this or that author with a view of observing its peculiarities. The thought of style, considered as an end in itself, has rarely, if ever, been present with him, his sole purpose being to express ideas as clearly as possible, and, when the occasion called for it, with as much force as might be. He has observed, however, he says, that some difference has been made in his style by the practice of dictation. Up to 1860 his books and review articles were written with his own hand. Since then they have all been dictated. He thinks that there is foundation for the prevailing belief that dictation is apt to cause diffuseness. The remark was once made to him, it seems, by two good judges–George Henry Lewes and George Eliot–that the style of "Social Statics" is better than the style of his later volumes; Mr. Spencer would ascribe the contrast to the deteriorating effect of dictation. A recent experience has strengthened him in this conclusion. When lately revising "First Principles," which originally was dictated, the cutting out of superfluous words, clauses, sentences, and sometimes paragraphs, had the effect of abridging the work by about one-tenth. Touching the style of other writers, Mr. Spencer points out the defects in some passages quoted from Matthew Arnold and Froude. He says that he is repelled by the ponderous, involved structure of Milton's prose, and he dissents from the applause of Ruskin's style on the ground that it is too self-conscious, and implies too much thought of effect. On the other hand, he has always been attracted by the finished naturalness of Thackeray.

A word should here be said about the misconception of Mr. Spencer's position with reference to the fundamental postulate of religions,–a misconception which used to be more current than it is now. He cannot fairly be described as a materialist. He is no more a materialist than he is a theist. He is, in the strictest sense of the word, an agnostic. He was the most conspicuous example of the thing before Huxley invented the word. The misconception was shared by no less a man than the late Benjamin Jowett, the well-known master of Balliol College, Oxford, who, in one of his published "Letters," says: "I sometimes think that we platonists and idealists are not half so industrious as those repulsive people who only 'believe what they can hold in their hand,' Bain, H. Spencer, etc., who are the very Tuppers of philosophy." It is hard to see how the law of evolution and other generalizations of an abstract kind with which Mr. Spencer's name is associated can be held in anybody's hands. Letting that pass, however, Mr. Spencer has himself suggested that, since the system of synthetic philosophy begins with a division entitled the "Unknowable," having for its purpose to show that all material phenomena are manifestations of a Power which transcends our knowledge,–that "force as we know it can be regarded only as a Conditioned effect of the Unconditioned Cause"–there has been thereby afforded sufficiently decided proof of belief in something which cannot be held in the hands. It is, indeed, absurd to apply the epithet "materialist" to a man who has written in "The Principles of Psychology": "Hence, though of the two it seems easier to translate so-called matter into so-called spirit than to translate so-called spirit into so-called matter (which latter is, indeed, wholly impossible), yet no translation can carry us beyond our symbols."

III

Any exposition of the "Synthetic Philosophy" must, of course, begin with the volume entitled "First Principles." In the first part of this preliminary work the author carries a step further the doctrine of the Unknowable put into shape by Hamilton and Mansel. He points out the various directions in which science leads to the same conclusion, and shows that in their united belief in an Absolute that transcends not only human knowledge but human conception lies the only possible reconciliation of science and religion. In the second part of the same book Mr. Spencer undertakes to formulate the laws of the Knowable. That is to say, he essays to state the ultimate principles discernible throughout all manifestations of the Absolute,–those highest generalizations now being disclosed by science, such, for example, as "the Conservation of Force," which are severally true, not of one class of phenomena, but of all classes of phenomena, and which are thus the keys to all classes of phenomena.

The conclusions reached in "First Principles" may be thus summed up: over and over again in the five hundred pages devoted to their formulation, it is shown in various ways that the deepest truths we can reach are simply statements of the widest uniformities in our experiences of the relations of Matter, Motion, and Force; and that Matter, Motion, and Force are but symbols of the Unknown reality. A Power of which the nature remains forever inconceivable, and to which no limits in Time and Space can be imagined, works in us certain effects. These effects have certain likenesses of kind, the most general of which we class together under the names of Matter, Motion, and Force; and between these effects there are likenesses of connection, the most constant of which we class as laws of the highest certainty. Analysis reduces these several kinds of effects to one kind of effect; and these several kinds of uniformity to one kind of uniformity. The highest achievement of Science is the interpretation of all orders of phenomena as differently conditioned manifestations of this one kind of effect, under differently conditioned modes of this one kind of uniformity. When science has done this, however, it has done nothing more than systematize our experiences, and has in no degree extended the limits of our experiences. We can say no more than before whether the uniformities are as absolutely necessary as they have become to our thought relatively necessary. The utmost possibility for us is an interpretation of the process of things, as it presents itself to our limited consciousness; but how this process is related to the actual process we are unable to conceive, much less to know.

Similarly we are admonished to remember that, while the connection between the phenomenal order and the ontological order is forever inscrutable, so is the connection between the conditioned forms of being and the unconditioned form of being forever inscrutable. The interpretation of all phenomena in terms of Matter, Motion, and Force is nothing more than the reduction of our complex symbols of thought to the simplest symbols; and when the equation has been brought to its lowest terms, the symbols remain symbols still. Hence the reasonings contained in "First Principles" afford no support to either of the antagonist hypotheses respecting the ultimate nature of things. Their implications are no more materialistic than they are spiritualistic, and no more spiritualistic than they are materialistic. The establishment of correlation and equivalence between the forces of the outer and the inner worlds serves to assimilate either to the other, according as we set out with one or the other. He who rightly interprets the doctrine propounded in "First Principles" will see that neither the forces of the outer, nor the forces of the inner, world can be taken as ultimate. He will see that, though the relation of subject and object renders necessary to us the antithetical conceptions of Spirit and Matter, the one is no less than the other to be regarded as but a sign of the Unknown Reality which underlies both.

In logical order the formulation of "First Principles" should have been followed by the application of them to Inorganic Nature. This great division of Mr. Spencer's subject is passed over, however; partly because, even without it, the scheme is too extensive to be carried out in the lifetime of one man; and partly because the interpretation of Organic Nature, after the proposed method, is of more immediate importance. Before noting how Mr. Spencer applies his fundamental principles to the interpretation of the phenomena of life, it may be well to put before the reader's eye the "formula of evolution" in the author's own language: "Evolution is an integration of matter and concomitant dissipation of motion; during which the matter passes from an indefinite, incoherent homogeneity to a definite, coherent heterogeneity; and during which the retained motion undergoes a parallel transformation." This law of evolution is equally applicable to all orders of phenomena,–"astronomic, geologic, biologic, psychologic, sociologic, etc.,"–since these are all component parts of one cosmos, though disguised from one another by conventional groupings. It is obvious that, so long as evolution is merely established by induction, it belongs, not to philosophy, but to science. To belong to philosophy it must be deduced from the persistence of force. Mr. Spencer holds that this can be done. For any finite aggregate, being unequally exposed to surrounding forces, will become more diverse in structure, every differentiated part will become the parent of further differences; at the same time, dissimilar units in the aggregate tend to separate, and those which are similar, to cluster together ("segregation"); and this subdivision and dissipation of forces, so long as there are any forces unbalanced by opposite forces, must end at last in rest; the penultimate stage of this process "in which the extremest multiformity and most complex moving equilibrium are established," being the highest conceivable state. The various derivative laws of phenomenal changes are thus deducible from the persistence of force. It remains to apply them to inorganic, organic, and superorganic existences. The detailed treatment of inorganic evolution is omitted, as we have said, from Spencer's plan, and he proceeds to interpret "the phenomena of life, mind, and society in terms of Matter, Motion, and Force."

IV

The first volume of the "Principles of Biology" consists of three parts, the first of which sets forth the data of biology, including those general truths of physics and chemistry with which rational biology must start. The second part is allotted to the inductions of biology, or, in other words, to a statement of the leading generalizations which naturalists, physiologists, and comparative anatomists have established. The third and final part of the first volume of the "Principles of Biology" deals with the speculation commonly known as "the development hypothesis," and considers its a priori and a posteriori evidences.

The inductive evidences for the evolutionary hypothesis, as contra-distinguished from the special-creation hypothesis, are dealt with in four chapters. The "Arguments from Classification" are these: Organisms fall into groups within groups; and this is the arrangement which we see results from evolution where it is known to take place. Of these groups within groups, the great or primary ones are the most unlike, the sub-groups are less unlike, the sub-sub-group still less unlike, and so on; and this, too, is a characteristic of groups demonstrably produced by evolution. Moreover, indefiniteness of equivalence among the groups is common to those which we know have been evolved, and to those supposed in the volume before us to have been evolved. There is the further significant fact that divergent groups are allied through their lowest rather than their highest members. Of the "Arguments from Embryology," the first is that, when developing embryos are traced from their common starting-point, and their divergencies and re-divergencies are symbolized by a genealogical tree, there is manifest a general parallelism between the arrangement of its primary, secondary, and tertiary branches, and the arrangement of the divisions and subdivisions of Mr. Spencer's classifications. Nor do the minor deviations from this general parallelism, which look like difficulties, fail on closer observation to furnish additional evidence; since those traits of a common ancestry which embryology reveals are, if modifications have resulted from changed conditions, liable to be disguised in different ways and degrees, in different lines of descendants. Mr. Spencer next considers the "Arguments from Morphology." Apart from those kinships among organisms disclosed by their developmental changes, the kinships which their adult forms show are profoundly significant. The unities of type found under such different externals are inexplicable, except as results of community of descent, with non-community of modification. Again, each organism analyzed apart shows, in the likenesses obscured by unlikenesses of its component parts, a peculiarity which can be ascribed only to the formation of a more heterogeneous organism out of a more homogeneous one. And, once more, the existence of rudimentary organs, homologous with organs that are developed in allied animals or plants, while it admits of no other rational interpretation, is satisfactorily interpreted by the hypothesis of evolution. Last of the inductive evidences are the "Arguments from Distribution." While the facts of distribution in space are unaccountable as results of designed adaptation of organisms to their habitats, they are accountable as results of the competition of species, and the spread of the more fit into the habitats of the less fit, followed by the changes which new conditions induce. Though the facts of distribution in time are so fragmentary that no positive conclusion can be drawn, yet all of them are reconcilable with the hypothesis of evolution, and some of them yield strong support,–especially the near relationship existing between the living and extinct types in each great geographical area. Thus of these four categories of evidence, each furnishes several arguments which point to the same conclusion. This coincidence would give to the induction a very high degree of probability, even were it not enforced by deduction. As a matter of fact, the conclusion deductively reached is in harmony with the inductive conclusion. Mr. Spencer has deductively shown that, by its lineage and its kindred, the evolution-hypothesis is as closely allied with the proved truths of modern science as is the antagonist hypothesis, that of special creation, with the proved errors of ancient ignorance. He has shown that, instead of being a mere pseud-idea, it admits of elaboration into a definite conception, so showing its legitimacy as an hypothesis. Instead of positing a purely fictitious process, the process which it alleges proves to be one actually going on around us. To which may be added that the evolution-hypothesis presents no radical incongruities from a moral point of view. On the other hand, the special-creation hypothesis is shown to be not even a thinkable hypothesis, and, while thus intellectually illusive, to have moral implications irreconcilable with the professed beliefs of those who hold it.

Passing from the evidence that Evolution has taken place to the question–How has it taken place?–Mr. Spencer finds in known agencies and known processes adequate causes of its phenomena. In astronomic, geologic, and meteorologic changes, ever in progress, ever combining in new and more involved ways, we have a set of inorganic factors to which all organisms are exposed; and in the varying and complicated actions of organisms on one another we have a set of organic factors that alter with increasing rapidity. Thus, speaking generally, all members of the Earth's flora and fauna experience perpetual rearrangements of external forces. Each organic aggregate, whether considered individually or as a continuously existing species, is modified afresh by each fresh distribution of external forces. To its pre-existing differentiations new differentiations are added; and thus that lapse to a more heterogeneous state, which would have a fixed limit were the circumstances fixed, has its limits perpetually removed by the perpetual change of the circumstances. These modifications upon modifications, which result in evolution, structurally considered, are the accompaniments of those functional alterations continually required to re-equilibrate inner with outer actions. That moving equilibrium of inner actions corresponding with outer actions, which constitutes the life of an organism, must either be overthrown by a change in the outer actions or must undergo perturbations that cannot end until there is a readjusted balance of functions and correlative adaptation of structures. But where the external changes are either such as are fatal when experienced by the individuals, or such as act on the individuals in ways that do not affect the equilibrium of their functions, then the readjustment results through the effects produced on the species as a whole: there is indirect equilibration. By the preservation in successive generations of those whose moving equilibria are less at variance with the requirements, there is produced a changed equilibrium completely in harmony with the requirements.

Even were this the whole of the evidence assignable for the belief that organisms have been gradually evolved, Mr. Spencer holds that the belief would have a warrant higher than is possessed by many beliefs which are regarded as established. As a matter of fact, however, the evidence is far from exhausted. At the outset of the first volume of "Principles of Biology," it was remarked by the author that the phenomena presented by the organic world as a whole cannot be properly dealt with apart from the phenomena presented by each organism in the course of its growth, development, and decay. The interpretation of either class of phenomena implies interpretation of the other, since the two are in reality parts of one process. Hence the validity of any hypothesis respecting the one class of phenomena may be tested by its congruity with phenomena of the other class. In the second volume of "The Principles of Biology," Mr. Spencer passes to the more special phenomena of development, as displayed in the structures and functions of individual organisms. If the hypothesis that plants and animals have been progressively evolved be true, it must furnish us with keys to these special phenomena. Mr. Spencer finds that the hypothesis does this, and by doing it gives numberless additional vouchers for its truth. It is impossible for us here to review, even in outline, the extensive field traversed in the second volume of "Principles of Biology." We would not omit, however, to direct attention to the interesting conclusion reached by Mr. Spencer toward the close of the volume with regard to the future of the human race considered from the viewpoint of the possible pressure of population upon subsistence. He points out that in man all the equilibrations between constitution and conditions, between the structure of society and the nature of its members, between fertility and mortality, advance simultaneously towards a common climax. In approaching an equilibrium between his nature and the ever-varying circumstances of his inorganic environment, and in approaching an equilibrium between his nature and all the requirements of the social state, man is at the same time approaching that lowest limit of fertility at which the equilibrium of population is maintained by the addition of as many infants as there are subtractions by death.