All alike, indeed, were blind to the factor of heredity.

But the theory in its collective application contains a truth which nineteenth century critics, biassed by their studies in heredity, have been prone to overlook.

The social inheritance of ideas and emotions to which the individual is submitted from infancy is more important than the tendencies physically transmitted from parent to child.

The power of education and government in moulding the members of a society has recently been illustrated on a large scale in the psychological transformation of the German people in the life of a generation.
It followed from the theory expounded by Helvetius that there is no impassable barrier between the advanced and the stationary or retrograde races of the earth.

[Footnote: The most informing discussion of the relations between the Advanced and Backward races is Bryce's Romanes Lecture (1902).] "True morality," Baron d'Holbach wrote, "should be the same for all the inhabitants of the globe.