Abstract This essay explores what it is to be a principle of charity in philosophical argumentation. In it, I explore some principles of charity found in classic and contemporary literature and textbooks on logic and philosophy. I distinguish between what I will maximal and sub-maximal principles of charity. With this distinction, I taxonomize current principles of charity on offer according to their dialectical function as rules for argument interpretation and reconstruction in philosophical argumentation. Principles of charity, I argue, are best construed as pragmatic rules for argument interpretation in philosophical argumentation, not merely moral or ratio-epistemic rules. I defend this claim against some objections.