This article aims to initiate a critical reconstruction of theory and research on reasoning and personal epistemology prompted by socio-philosophical critiques of rationalism and by a theoretical perspective according to which both discourses of knowledge and modes of thought are constituted in a power-infused sociocultural order structured materially and discursively by gender, ‘race,’ and socioeconomic class. A new qualitative methodology is introduced, particularizing participants in terms of their social location and modes of thought while also formulating cross-sectional analytical constructs. New analytical constructs for characterizing epistemic resources ostensibly brought into reasoning are interpretively induced from data through a quasi-inductive process informed by critical philosophical perspectives on knowledge. Theoretical implications point to the functional interplay of dominant and subversive discourses of knowledge in the constitution of thought, the complex assemblage of discursive resources flexibly deployed in reasoning, and the social constitution and biographical particularity of reasoners as epistemic agents.