other； as Knies said； of the immutability of the old zoology； did not long hold out against the ever swelling tide of the historical movement。 Knowledge of the transformations that had taken place in language； of the early phases of the family； of religion； of property； had all favoured the revival of the Heraclitean view： panta rei。 As to the categories of political economy； it was soon to be recognised； as by Lassalle； that they too are only historical。 The philosophy of history； moreover； gave expression under various forms to the same tendency。 Hegel declares that 〃all that is real is rational；〃 but at the same time he shows that all that is real is ephemeral； and that for history there is nothing fixed beneath the sun。 It is this sense of universal evolution that Darwin came with fresh authority to enlarge。 It was in the name of biological facts themselves that he taught us to see only slow metamorphoses in the history of institutions； and to be always on the outlook for survivals side by side with rudimentary forms。 Anyone who reads 〃Primitive Culture〃； by Tylor；a writer closely connected with Darwinwill be able to estimate the services which these cardinal ideas were to render to the social sciences when the age of comparative research had succeeded to that of a priori construction。
Let us note； moreover； that the philosophy of Becoming in passing through the Darwinian biology became； as it were； filtered： it got rid of those traces of finalism； which； under different forms； it had preserved through all the systems of German Romanticism。 Even in Herbert Spencer； it has been plausibly argued； one can detect something of that sort of mystic confidence in forces spontaneously directing life； which forms the very essence of those systems。 But Darwin's observations were precisely calculated to render such an hypothesis futile。 At first people may have failed to see this； and we call to mind the ponderous sarcasms of Flourens when he objected to the theory of Natural Selection that it attributed to nature a power of free choice。 〃Nature endowed with will！ That was the final error of last century； but the nineteenth no longer deals in personifications。〃 （P。 Flourens； 〃Examen du Livre de M。 Darwin sur l'Origine des Especes〃； page 53； Paris； 1864。 See also Huxley； 〃Criticisms on the 'Origin of Species'〃； 〃Collected Essays〃； Vol。 II； page 102； London； 1902。） In fact Darwin himself put his readers on their guard against the metaphors he was obliged to use。 The processes by which he explains the survival of the fittest are far from affording any indication of the design of some transcendent breeder。 Nor； if we look closely； do they even imply immanent effort in the animal； the sorting out can be brought about mechanically； simply by the action of the environment。 In this connection Huxley could with good reason maintain that Darwin's originality consisted in showing how harmonies which hitherto had been taken to imply the agency of intelligence and will could be explained without any such intervention。 So； when later on； objective sociology declares that； even when social phenomena are in question； all finalist preconceptions must be distrusted if a science is to be constituted； it is to Darwin that its thanks are due； he had long been clearing paths for it which lay well away from the old familiar road trodden by so many theories of evolution。
This anti…finalist doctrine； when fully worked out； was； moreover； calculated to aid in the needful dissociation of two notions： that of evolution and that of progress。 In application to society these had long been confounded； and； as a consequence； the general idea seemed to be that only one type of evolution was here possible。 Do we not detect such a view in Comte's sociology； and perhaps even in Herbert Spencer's？ Whoever； indeed； assumes an end for evolution is naturally inclined to think that only one road leads to that end。 But those whose minds the Darwinian theory has enlightened are aware that the transformations of living beings depend primarily upon their conditions； and that it is these conditions which are the agents of selection from among individual variations。 Hence； it immediately follows that transformations are not necessarily improvements。 Here； Darwin's thought hesitated。 Logically his theory proves； as Ray Lankester pointed out； that the struggle for existence may have as its outcome degeneration as well as amelioration： evolution may be regressive as well as progressive。 Then； tooand this is especially to be borne in mindeach species takes its good where it finds it； seeks its own path and survives as best it can。 Apply this notion to society and you arrive at the theory of multilinear evolution。 Divergencies will no longer surprise you。 You will be forewarned not to apply to all civilisations the same measure of progress； and you will recognise that types of evolution may differ just as social species themselves differ。 Have we not here one of the conceptions which mark off sociology proper from the old philosophy of history？
But if we are to estimate the influence of Darwinism upon sociological conceptions； we must not dwell only upon the way in which Darwin impressed the general notion of evolution upon the minds of thinkers。 We must go into details。 We must consider the influence of the particular theories by which he explained the mechanism of this evolution。 The name of the author of 〃The Origin of Species〃 has been especially attached； as everyone knows； to the doctrines of 〃natural selection〃 and of 〃struggle for existence；〃 completed by the notion of 〃individual variation。〃 These doctrines were turned to account by very different schools of social philosophy。 Pessimistic and optimistic； aristocratic and democratic； individualistic and socialistic systems were to war with each other for years by casting scraps of Darwinism at each other's heads。
It was the spectacle of human contrivance that suggested to Darwin his conception of natural selection。 It was in studying the methods of pigeon breeders that he divined the processes by which nature； in the absence of design； obtains analogous results in the differentiation of types。 As soon as the importance of artificial selection in the transformation of species of animals was understood； reflection naturally turned to the human species； and the question arose； How far do men observe； in connection with themselves； those laws of which they make practical application in the case of animals？ Here we come upon one of the ideas which guided the researches of Galton； Darwin's cousin。 The author of 〃Inquiries into Human Faculty and its Development〃 （〃Inquiries into Human Faculty〃； pages 1； 2； 3 sq。； London； 1883。）； has often expressed his surprise that； considering all the precautions taken； for example； in the breeding of horses； none whatever are taken in the breeding of the human species。 It seems to be forgotten that the species suffers when the 〃fittest〃 are not able to perpetuate their type。 Ritchie； in his 〃Darwinism and Politics〃 （〃Darwinism and Politics〃 pages 9； 22； London； 1889。） reminds us of Darwin's remark that the institution of the peerage might be defended on the ground that peers； owing to the prestige they enjoy； are enabled to select as wives 〃the most beautiful and charming women out of the lower ranks。〃 （〃Life and Letters of Charles Darwin〃； II。 page 385。） But； says Galton； it is as often as not 〃heiresses〃 that they pick out； and birth statistics seem to show that these are either less robust or less fecund than others。 The truth is that considerations continue to preside over marriage which are entirely foreign to the improvement of type； much as this is a condition of general progress。 Hence the importance of completing Odin's and De Candolle's statistics which are designed to show how characters are incorporated in organisms； how they are transmitted； how lost； and according to what law eugenic elements depart from the mean or return to it。
But thinkers do not always content themselves with undertaking merely the minute researches which the idea of Selection suggests。 They are eager to defend this or that thesis。 In the name of this idea certain social anthropologists have recast the conception of the process of civilisation； and have affirmed that Social Selection generally works against the trend of Natural Selection。 Vacher de Lapougefollowing up an observation by Broca on the pointenumerates the various institutions； or customs； such as the celibacy of priests and military conscription； which cause elimination or sterilisation of the bearers of certain superior qualities； intellectual or physical。 In a more general way he attacks the democratic movement； a movement； as P。 Bourget says； which is 〃anti…physical〃 and contrary to the natural laws of progress； though it has been inspired 〃by the dreams of that most visionary of all centuries； the eighteenth。〃 （V。 de Lapouge； 〃Les Selections sociales〃； page 259； Paris； 1896。） The 〃Equality〃 which levels down and mixes （justly condemned； he holds； by the Comte de Gobineau）； prevents the aristocracy of the blond dolichocephales from holding the position and playing the part which； in the interests of all； should belong to them。 Otto Ammon； in his 〃Natural Selection in Man〃； and in 〃The Social Order and its Natural Bases〃 （〃Die naturliche Auslese beim Menschen〃； Jena； 1893； 〃Die Gesellschaftsordnung und ihre naturlichen Grundlagen〃。 〃Entwurf einer Sozialanthropologie〃； Jena； 1896。）； defended analogous doctrines in Germany； setting the curve representing frequency of talent over against that of income； he attempted to show that all democratic measures which aim at promoting the rise in the social scale of the talented are useless； if not dangerous； that they only increase the panmixia； to the great detriment of the species and of society。
Among the aristocratic theories which Darwinism has thus inspired we must reckon that of Nietzsche。 It is well known that in order to complete his philosophy he added biological studies to his philological； and more than once in his remarks upon the 〃Wille zur Macht〃 he definitely alludes to Darwin； though it must be confessed that it is generally in order t