The interactions between Charles Darwin and Thomas Henry Huxley are widely misunderstood. Huxley neither rejected Darwin’s core ideas nor accepted them uncritically; instead, each scientist strongly influenced the other over a period of several decades. Fully understanding their debate requires understanding the rhetoric of the time, which leads to a realization that nineteenth-century scientists were familiar with a rhetoric of science that addresses many of the same issues that the discipline does today. The rhetorician Benjamin Humphrey Smart, although almost forgotten today, was highly influential not only on Darwin, but on the physicist Michael Faraday and the philosopher of science John Stuart Mill. His ideas set much of the background for the debate.