Thus, Dumont's pleasure in the expansion of power, Roux's internal struggle, Nägeli's drive towards complexity, and Rolph's principle of insatiability and assimilation are fused together into the biological side of Nietzsche's theory of will to power, which is developed in a number of places in his published writings. Having derived the "will to power" from three anti-Darwin evolutionists, as well as Dumont, it seems appropriate that he should use his "will to power" as an anti-Darwinian explanation of evolution. He expresses a number of times the idea that adaptation and the struggle to survive is a secondary drive in the evolution of animals, behind the desire to expand one's power – the "will to power".