In this paper, I aim to address a specific issue underpinning Cartesian metaphysics since its first public appearance in the Discourse right up until the Meditations, but which definitely came to the surface in the Second and Fifth Replies. It involves the possibility that to be thinking and to be extended do not actually contrast as two entirely different properties; hence, these two essences cannot serve as the basis for a disjunctive, real distinction between two corresponding substances, the mind and (...) the body. I dub this problem the ‘thinking matter issue.’ I suggest that Descartes’s concerns about the ‘thinking matter issue’ characterizes and structures the entirety of Meditation Two and its connection with Meditation Six, especially in the attempt to covertly implement what I refer to as Descartes’s ‘prejudice strategy.’ The core of the ‘prejudice strategy’ lies in the idea that the ‘thinking matter issue’ is just a false problem, one raised by the inadequate notions of the mind and the body that we apply to this problem. In section 1, I set out the way in which the ‘thinking matter issue’ emerged in Descartes’s philosophy after the first exposition of his metaphysics in the Discourse. Section 2 deals with the new argumentative path Descartes draws for the Meditations and with the new role that he assigns to the inference about the mind’s non-physical nature after the cogito. In section 3, I contend that the ‘prejudice strategy’ structures Meditation Two and, partially, Six. Section 4 shows that Descartes himself reveals this in his Replies to the Second and the Fifth Set of Objections. In section 5, I delve into Descartes’s foundational theory of the ‘prejudice strategy,’ i.e. his theory of infancy as set out especially in the Replies to the Sixth Set of Objections. -/- . (shrink)