This investigation focused on a group of 17 faculty drawn from disciplines in the humanities social sciences and natural sciences. Using in-depth interviews, focus group discussions and qualitative coding strategies, this study examined how faculty conceptualized the term critical thinking (CT), and how they assessed for it in general education courses. The study adopted an exploratory approach and hence did not use an operational definition of CT. This study found that that faculty assessed for CT implicitly through disciplinary content. Their approach focused on aspects of CT that were most relevant to their disciplinary needs. Faculty in the natural sciences leaned toward rationalistic, empirical approaches, faculty from philosophy focused on rationality and formulaic procedural processes, faculty in the humanities focused on aporetic elements of CT, and faculty in the social sciences relied on empirical artifacts and standards while recognizing the role of perspective in CT. Faculty rejected the use of multiple choice tests as a valid means of assessing CT. They assessed for CT through other communicative learning outcomes. Faculty did not use formal assessment instruments to explicitly assess for CT and hence had no way to gauge the efficacy of their pedagogical approaches. This study raises questions on the efficacy of discipline-general assessment approaches used by national governing bodies, commercial standardized tests and general education programs to teach and assess CT in general education. It presents empirical evidence on the need for a complex, multi-disciplinary, inclusive approach to conceptualizing CT. An approach that reflects how faculty approach CT in the undergraduate classroom and fulfills the aspirations for multi-disciplinarity in general education. The findings of this study have implications for the assessment of CT in general education, national accountability efforts and for faculty development. (Contains 6 figures and 1 table.)