The central theme of this study is that Descartes is a teacher who develops his arguments for the different philosophical orientations of his students. Indeed, according to Cunning, so respectful is Descartes of their orientations that he actually misrepresents his own view in the Meditations on central doctrinal matters like the basis for dualism. The exegetical argument for this is the central argument of the book, though many other aspects of the Meditations are discussed in novel and interesting ways.
Descartes describes himself as establishing the duality of mental and physical substances in two stages in the Meditations. It is in Meditation II, he says in the Fourth Replies, where he shows that a clear and distinct idea of the self excludes all corporeal properties. On standard readings, what is shown to be clear and distinct is that I am a substance with only mental properties essentially; what still needs to be shown is that this substance is distinct from my body. This, the “real distinction” between the mind and the body, is demonstrated only in Meditation VI from the potentiality in God to separate mental substance from physical substance. The real distinction consists of this divine capability and constitutes Descartes’ own argument for this doctrine. However, according to Cunning, the standard view has to be wrong because it entails that there are unactualized possibilities that God could will [End Page 497] into formal being, something that is inconsistent with Descartes’ own view, presented in other writings, that there are no unactualized possibilities that God could will (“Necessitarianism”). So, the Sixth Meditation argument is not given in Descartes’ own voice. In light of this, Cunning reinterprets what Meditation II shows to be clear and distinct. He argues that the Cartesian self is not a substance in Meditation II and so it is not clear and distinct that the mind is an immaterial substance, but some less metaphysically determined immaterial entity. The claim to immaterial substancehood is made in only in Meditation VI. This interpretation makes an important and original contribution to the literature.
What, then, is Descartes’ official argument for mind-body dualism? Surprisingly, Cunning finds the first stage of this argument in the Argument from Doubt of Discourse IV. He maintains that this argument should not be interpreted as it usually is, as fallacious, but as a strategy of arguing from the premises, (1) if in the domain of the mind there were material elements, we would know of their existence, hence of the existence of material things overall, but (2) we do not know of the existence of material things overall, ergo, there are in the domain of the mind no material elements. The second stage of the argument derives the substantiality of the self from Principles I, 52: that wherever there are perceptions of properties, there is a substance that contains those properties—similar to T. Vinci, Cartesian Truth (Oxford, 1998), 39–43. The final route to the real distinction between mind and body proceeds from Principles I, 53, the doctrine that all modes are determinations of a principal attribute, and Principles I, 63, that for every principal attribute there is one and only one principal substance—similar to M. Rozemond, Descartes’ Dualism (Harvard, 1998), 1–38 (noted by Cunning).
My assessment of this interpretation is somewhat mixed. Positively, it corrects an unjust and uncharitable reading of the Argument from Doubt and closely observes important features of Descartes’ reasoning in the Discourse, the Meditations, and the Principles. But there are difficulties, of which I will mention two: (1) The one attribute–one substance principle of Principles I, 63 rests on Descartes’ claim that there is only a conceptual distinction between substance and attribute. This is intelligible as a claim about the relationship between substances in general and their principle attributes, but not as a claim about the relationship between particular substances and attributes (see Principles I, 64). But it is the latter relationship that is at issue in the Discourse and the Meditations. (2) The absence of an argument for the substantiality of...