The purpose of this reply to Stiles’ (2009) article is threefold: identify his particular philosophy of theory-building, expose some of its problems for evaluation, and describe another philosophy of theory-building as a point of comparison. The article begins by describing how Stiles’ philosophical approach to theory-building is ontologically dualist in nature. Dualism is evident in his view of experience, signs, meanings, knowledge, and truth. We point not only to general problems with this dualism but also to specific problems with Stiles’ particular formulation. We then describe a nondualist philosophy in a successful case study movement outside psychology, namely Consumer Reports car ratings. It is only in comparison with such nondualist approaches that we can begin to evaluate Stiles’ proposal and properly serve the important project of case study evaluation.