In the recently discovered Cambridge manuscript, widely regarded as an early draft of Rules for the Direction of the Mind, Descartes does not describe the mind as a ‘purely spiritual’ force ‘distinct from the whole body’. This has led some readers to speculate that Descartes did not embrace mind-body dualism in the Cambridge manuscript. In this article, I offer a detailed interpretation of Descartes's mind-body dualism in the established Charles Adam and Paul Tannery edition of Rules, and argue that, while differences between the Cambridge manuscript and the established version of Rules are significant, the relevant passages in the Cambridge manuscript preclude interpretation along both materialist and hylomorphic lines. I then offer an account of the development of Descartes's mind-body dualism between the Cambridge manuscript and the established version of Rules. What the Cambridge manuscript reveals is not Descartes before dualism, but rather Cartesian dualism in its barest form.

According to Reid, color sensations are not extended nor are they arranged in figured patterns. Reid further claimed that ‘there is no sensation appropriated to visible figure.’ Reid justified these controversial claims by appeal to Cheselden's report of the experiences of a young man affected by severe cataracts, and by appeal to cases of perception of visible figure without color. While holding fast to the principle that sensations are not extended, Dugald Stewart (1753–1828) tried to show that ‘a variety of colour sensations is a necessary means for the perception of visible figure.’ According to John Fearn (1768–1837), two motives appear to be central to Reid's views about color sensations and extension: his commitment to the Cartesian doctrine of the immateriality of the soul, and his attempt to evade ‘Hume's dilemma’ about the existence and immateriality of the soul.