The encounter between Buddhism and science has long been recognized as one of the key events in the formulation of Buddhist modernisms. Yet only recently has this begun to be explored in its historic specificity. This paper examines Republican-era Chinese Buddhist engagement with the theory of evolution at the peak of its cultural influence in the 1920s and 1930s. It argues that while Buddhists largely accepted biological evolution, Darwinist theories of survival of the fittest were rejected. Instead, they embraced the alternative theory of Peter Kropotkin, who saw mutual aid as the driving force of evolution. This theory was not only less offensive to Buddhist sensibilities, but also amenable to a rhetorical strategy of subsumption in which Kropotkin was presented as anticipated and fulfilled by Buddhist doctrine. This tactic allowed Buddhists to portray their religion as modern, scientific, and progressive while avoiding what were seen as the pernicious corollaries of Darwinism. Effectively, Buddhists who employed this tactic attempted to annex Kroptokin’s discursive space, taking advantage of the internal variegation of modernity in order to constitute it as part of a modern discourse and superscribe that discourse with their own concerns.