s 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 Especes_, 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 Selections sociales_, p. 259,
Paris, 1896.]

[Footnote 251: _Die nataerliche Auslese beim Menschen_, Jena, 1893; _Du
Gesellschaftsordnung und ihre natuerlichen Grundlagen. Entwurf einer
Sozialanthropologie_, Jena, 1896.]

[Footnote 252: _Etudes sur la Selection dans ses rapports avec
l'heredite chez l'homme_, Paris, p. 481, 1881.]

[Footnote 253: _Die drei Bevoelkerungsstufen_, Munich, 1889.]

[Footnote 254: _Evolution and Ethics_, p. 200; _Collected Essays_,
Vol. IX, London, 1894.]

[Footnote 255: _Les Luttes entre Societes humaines et