ABSTRACT
Professor of rhetoric John Angus Campbell has termed Darwin “the invisible rhetorician” and, indeed, Darwin’s On the Origin of Species is in many ways a masterpiece of rhetoric. Absent the conclusive proof of natural selection that Huxley and others desired, Darwin had to craft a case for the probability of that process—and probability, as Aristotle notes, is the realm of rhetoric. Mindful of the prevalence of natural theology, Darwin perhaps disingenuously included two quotations on the flyleaf of the first edition of Origin that suggested a divine presence behind the workings of natural selection—an idea of great appeal to his American champion Asa Gray. In the second edition of Origin, published in January 1860, he also revised the final paragraph to include the idea of a creator setting natural laws into motion.
