Rationalization, in our intended sense of the term, occurs when a person favors a particular conclusion as a result of some factor (such as self-interest) that is of little justificatory epistemic relevance, if that factor then biases the person’s subsequent search for, and assessment of, potential justifications for the conclusion. Empirical evidence suggests that rationalization is common in people’s moral and philosophical thought. We argue that it is likely that the moral and philosophical thought of philosophers and moral psychologists is also pervaded by rationalization. Moreover, although rationalization has some benefits, overall it would be epistemically better if the moral and philosophical reasoning of people, including professional academics, were not as heavily influenced by rationalization as it likely is. We discuss the significance of our arguments for cognitive management and epistemic responsibility.