And we might take another example, at the other end of the series of sociological systems. G. Tarde is a sociologist with the most pronounced anti-naturalistic views. He has attempted to show that all application of the laws of natural science to society is misleading. In his _Opposition Universelle_ he has directly combatted all forms of sociological Darwinism. According to him the idea that the evolution of society can be traced on the same plan as the evolution of species is chimerical. Social evolution is at the mercy of all kinds of inventions, which by virtue of the laws of imitation modify, through individual to individual, through neighbourhood to neighbourhood, the general state of those beliefs and desires which are the only "quantities" whose variation matters to the sociologist. But, it may be rejoined, that however psychical the forces may be, they are none the less subject to Darwinian laws. They compete with each other; they struggle for the mastery of minds. Between types of ideas, as between organic forms, selection operates. And though it may be that these types are ushered into the arena by unexpected discoveries, we yet recognise in the psychological accidents, which Tarde places at the base of everything, near relatives of those small accidental variations upon which Darwin builds. Thus, accepting Tarde's own representations, it is quite possible to express in Darwinian terms, with the necessary transpositions, one of the most idealistic sociologies that have ever been constructed. These few examples suffice. They enable us to estimate the extent of the field of influence of Darwinism. It affects sociology not only through the agency of its advocates but through that of its opponents. The questions to which it has given rise have proved no less fruitful than the solutions it has suggested. In short, few doctrines, in the history of social philosophy, will have produced on their passage a finer crop of ideas. FOOTNOTES: [Footnote 246: P. Flourens, _Examen du Livre de M. Darwin sur l'Origine des Espèces_, p. 53, Paris, 1864. See also Huxley, "Criticisms on the _Origin of Species," Collected Essays_, Vol. II, p. 102, London, 1902.] [Footnote 247: _Inquiries into Human Faculty_, pp. 1, 2, 3 sq., London, 1883.] [Footnote 248: _Darwinism and Politics_, pp. 9, 22, London, 1889.] [Footnote 249: _Life and Letters of Charles Darwin_, II. p. 385.] [Footnote 250: V. de Lapouge, _Les Sélections sociales_, p. 259, Paris, 1896.] [Footnote 251: _Die natärliche Auslese beim Menschen_, Jena, 1893; _Du Gesellschaftsordnung und ihre natürlichen Grundlagen. Entwurf einer Sozialanthropologie_, Jena, 1896.] [Footnote 252: _Etudes sur la Sélection dans ses rapports avec l'hérédité chez l'homme_, Paris, p. 481, 1881.] [Footnote 253: _Die drei Bevölkerungsstufen_, Munich, 1889.] [Footnote 254: _Evolution and Ethics_, p. 200; _Collected Essays_, Vol. IX, London, 1894.]