We argue that the rhetoric of science occupies an important niche in contemporary science studies. Although we are pluralistic about how different rhetoricians of science can and do conduct their inquiries, we assert that their disciplinarily distinctive approach is to treat argumentation as a constituent of context. From this perspective, we observe various interacting forms of rationality at work in the controversies that constitute science in society. We argue that modes of discovery and modes of proof are mutually engaged in the process of rhetorical invention. We identify a variety of topics or commonplaces that show invention as we conceive it at work. We take a pro-science attitude toward the role of science in finding the truth and in sustaining democratic institutions.