While a young law student at the University of Poitiers, Vacher de Lapouge read Herbert Spencer and Charles Darwin.

Vacher de Lapouge added to this concept of races and classes what he termed selectionism, his version of Galton's eugenics.

Lapouge in 1887 had predicted that the 20th century would witness genocides that slaughtered millions over their alleged racial differences, though he was not saying this should occur.

He wrote of "anti-morality" (moral nihilism), along with proposing a totalitarian "selectionist" state that would strictly enforce racist eugenics.

[8] Lapouge's work spurred a strong reaction on the political left in France, since it was seen as undermining the democratic Enlightenment values which they cherished with science, generally deemed their friend (he had repudiated the Revolutionary slogan “Liberty, Equality, Fraternity”, saying this should be replaced with “Determinism, Inequality, Selection”).

His work left secular leftists with a quandary, since they cited science (some of the same as Lapouge) to advance their own views, though his were opposed to theirs.

Anthropologists who shared their views attacked Lapouge's theories, along with the racist and sexist ideas common in anthropology then generally.

They feared that if science were upheld as determining social values, the threat his theories posed (or similar ones) would always exist.

Lapouge complained bitterly of this, and particularly hated one critic who was Jewish, saying his theories had been rejected because of French Jews' influence.