Critical thinking skills are often assessed via student beliefs in non-scientific ways of thinking, (e.g, pseudoscience). Courses aimed at reducing such beliefs have been studied in the STEM fields with the most successful focusing on skeptical thinking. However, critical thinking is not unique to the sciences; it is crucial in the humanities and to historical thinking and analysis. We investigated the effects of a history course on epistemically unwarranted beliefs in two class sections. Beliefs were measured pre- and post-semester. Beliefs declined for history students compared to a control class and the effect was strongest for the honors section. This study provides evidence that a humanities education engenders critical thinking. Further, there may be individual differences in ability or preparedness in developing such skills, suggesting different foci for critical thinking coursework.