cheson； Hume and Adam Smith。 Because he is no philosopher in the stricter sense of the term； it is of great interest to see that his attitude of mind is that of the great thinkers of his nation。
In considering Darwin's influence on philosophy we will begin with an examination of the attitude of philosophy to the conception of evolution at the time when 〃The Origin of Species〃 appeared。 We will then examine the effects which the theory of evolution； and especially the idea of the struggle for life； has had； and naturally must have； on the discussion of philosophical problems。
II。
When 〃The Origin of Species〃 appeared fifty years ago Romantic speculation； Schelling's and Hegel's philosophy； still reigned on the continent； while in England Positivism； the philosophy of Comte and Stuart Mill； represented the most important trend of thought。 German speculation had much to say on evolution； it even pretended to be a philosophy of evolution。 But then the word 〃evolution〃 was to be taken in an ideal； not in a real； sense。 To speculative thought the forms and types of nature formed a system of ideas； within which any form could lead us by continuous transitions to any other。 It was a classificatory system which was regarded as a divine world of thought or images； within which metamorphoses could go ona condition comparable with that in the mind of the poet when one image follows another with imperceptible changes。 Goethe's ideas of evolution； as expressed in his 〃Metamorphosen der Pflanzen und der Thiere〃； belong to this category； it is； therefore； incorrect to call him a forerunner of Darwin。 Schelling and Hegel held the same idea； Hegel expressly rejected the conception of a real evolution in time as coarse and materialistic。 〃Nature；〃 he says； 〃is to be considered as a SYSTEM OF STAGES； the one necessarily arising from the other； and being the nearest truth of that from which it proceeds； but not in such a way that the one is NATURALLY generated by the other； on the contrary （their connection lies） in the inner idea which is the ground of nature。 The METAMORPHOSIS can be ascribed only to the notion as such； because it alone is evolution。。。It has been a clumsy idea in the older as well as in the newer philosophy of nature； to regard the transformation and the transition from one natural form and sphere to a higher as an outward and actual production。〃 （〃Encyclopaedie der philosophischen Wissenschaften〃 （4th edition）； Berlin； 1845； paragraph 249。）
The only one of the philosophers of Romanticism who believed in a real； historical evolution； a real production of new species； was Oken。 （〃Lehrbuch der Naturphilosophie〃； Jena； 1809。） Danish philosophers； such as Treschow （1812） and Sibbern （1846）； have also broached the idea of an historical evolution of all living beings from the lowest to the highest。 Schopenhauer's philosophy has a more realistic character than that of Schelling's and Hegel's； his diametrical opposites； though he also belongs to the romantic school of thought。 His philosophical and psychological views were greatly influenced by French naturalists and philosophers； especially by Cabanis and Lamarck。 He praises the 〃ever memorable Lamarck；〃 because he laid so much stress on the 〃will to live。〃 But he repudiates as a 〃wonderful error〃 the idea that the organs of animals should have reached their present perfection through a development in time； during the course of innumerable generations。 It was； he said； a consequence of the low standard of contemporary French philosophy； that Lamarck came to the idea of the construction of living beings in time through succession！ （〃Ueber den Willen in der Natur〃 （2nd edition）； Frankfurt a。 M。； 1854； pages 41…43。）
The positivistic stream of thought was not more in favour of a real evolution than was the Romantic school。 Its aim was to adhere to positive facts： it looked with suspicion on far…reaching speculation。 Comte laid great stress on the discontinuity found between the different kingdoms of nature； as well as within each single kingdom。 As he regarded as unscientific every attempt to reduce the number of physical forces； so he rejected entirely the hypothesis of Lamarck concerning the evolution of species； the idea of species would in his eyes absolutely lose its importance if a transition from species to species under the influence of conditions of life were admitted。 His disciples （Littre； Robin） continued to direct against Darwin the polemics which their master had employed against Lamarck。 Stuart Mill； who； in the theory of knowledge； represented the empirical or positivistic movement in philosophylike his English forerunners from Locke to Humefounded his theory of knowledge and morals on the experience of the single individual。 He sympathised with the theory of the original likeness of all individuals and derived their differences； on which he practically and theoretically laid much stress； from the influence both of experience and education； and； generally； of physical and social causes。 He admitted an individual evolution； and； in the human species； an evolution based on social progress； but no physiological evolution of species。 He was afraid that the hypothesis of heredity would carry us back to the old theory of 〃innate〃 ideas。
Darwin was more empirical than Comte and Mill； experience disclosed to him a deeper continuity than they could find； closer than before the nature and fate of the single individual were shown to be interwoven in the great web binding the life of the species with nature as a whole。 And the continuity which so many idealistic philosophers could find only in the world of thought； he showed to be present in the world of reality。
III。
Darwin's energetic renewal of the old idea of evolution had its chief importance in strengthening the conviction of this real continuity in the world； of continuity in the series of form and events。 It was a great support for all those who were prepared to base their conception of life on scientific grounds。 Together with the recently discovered law of the conservation of energy； it helped to produce the great realistic movement which characterises the last third of the nineteenth century。 After the decline of the Romantic movement people wished to have firmer ground under their feet and reality now asserted itself in a more emphatic manner than in the period of Romanticism。 It was easy for Hegel to proclaim that 〃the real〃 was 〃the rational；〃 and that 〃the rational〃 was 〃the real〃： reality itself existed for him only in the interpretation of ideal reason； and if there was anything which could not be merged in the higher unity of thought； then it was only an example of the 〃impotence of nature to hold to the idea。〃 But now concepts are to be founded on nature and not on any system of categories too confidently deduced a priori。 The new devotion to nature had its recompense in itself； because the new points of view made us see that nature could indeed 〃hold to ideas；〃 though perhaps not to those which we had cogitated beforehand。
A most important question for philosophers to answer was whether the new views were compatible with an idealistic conception of life and existence。 Some proclaimed that we have now no need of any philosophy beyond the principles of the conservation of matter and energy and the principle of natural evolution： existence should and could be definitely and completely explained by the laws of material nature。 But abler thinkers saw that the thing was not so simple。 They were prepared to give the new views their just place and to examine what alterations the old views must undergo in order to be brought into harmony with the new data。
The realistic character of Darwin's theory was shown not only in the idea of natural continuity； but also； and not least； in the idea of the cause whereby organic life advances step by step。 This ideathe idea of the struggle for lifeimplied that nothing could persist； if it had no power to maintain itself under the given conditions。 Inner value alone does not decide。 Idealism was here put to its hardest trial。 In continuous evolution it could perhaps still find an analogy to the inner evolution of ideas in the mind； but in the demand for power in order to struggle with outward conditions Realism seemed to announce itself in its most brutal form。 Every form of Idealism had to ask itself seriously how it was going to 〃struggle for life〃 with this new Realism。
We will now give a short account of the position which leading thinkers in different countries have taken up in regard to this question。
I。 Herbert Spencer was the philosopher whose mind was best prepared by his own previous thinking to admit the theory of Darwin to a place in his conception of the world。 His criticism of the arguments which had been put forward against the hypothesis of Lamarck； showed that Spencer； as a young man； was an adherent to the evolution idea。 In his 〃Social Statics〃 （1850） he applied this idea to human life and moral civilisation。 In 1852 he wrote an essay on 〃The Development Hypothesis〃； in which he definitely stated his belief that the differentiation of species； like the differentiation within a single organism； was the result of development。 In the first edition of his 〃Psychology〃 （1855） he took a step which put him in opposition to the older English school （from Locke to Mill）： he acknowledged 〃innate ideas〃 so far as to admit the tendency of acquired habits to be inherited in the course of generations； so that the nature and functions of the individual are only to be understood through its connection with the life of the species。 In 1857； in his essay on 〃Progress〃； he propounded the law of differentiation as a general law of evolution； verified by examples from all regions of experience； the evolution of species being only one of these examples。 On the effect which the appearance of 〃The Origin of Species〃 had on his mind he writes in his 〃Autobiography〃： 〃Up to that time。。。I held that the sole cause of organic evolution is the inheritance of functionally…produced modifications。 The 〃Origin of Species〃 made it clear to me that I was wrong； and that the larger part of the facts cannot be due to any such cause。。。T