The recent turn in teacher education reform in the United States toward hyper "professionalization" and assessment-based accreditation, spearheaded by the largest accrediting agency, the National Council for the Accreditation of Teacher Education (NCATE), has moved beyond codifying knowledge and skills to codifying the internal existence of those who desire to become teachers. The reform movement has entered into the territory of the virtue ethic with its emphasis on the notion of "dispositions." Whereas before college of education faculty were accountable for proving each preservice teacher had mastered certain "knowledge and skills," they now must also find ways to measure and assess whether the teacher candidate is the "right sort" of person, to borrow a phrase from ethical philosopher Edmund Pincoffs (1986). In this article I explore how "professionalism" retains some residue of the Aristotelian philosophical labor on dispositions but resituates and rewrites it into a different economy of thought, one built by tools of quantification, enumeration, and accountability rather than the practical wisdom of which Aristotle spoke.