Buddhism's reputation as a ‘scientific religion’ has led contemporary Buddhists to advocate eliminating the doctrine of karma and its metaphysical concept of rebirth. This movement to modernize Buddhism evinces little understanding of how the karma concept actually functions in Buddhist societies. This article argues that traditional Buddhists invoke karma performatively in order to orient their personal experiences rather than to make metaphysical claims. In doing so, Buddhist tradition challenges and enriches the limited sense of realism that takes precedence in the dialogue between Buddhism and science. This challenge needs to be appreciated in order to render Buddhism an equal partner in the dialogue rather than the mere object of scientific critique.