In Alan Gewirth’s The Cartesian Circle Reconsidered, he expands on an argument he made in a previous paper in regards to a possible logical fallacy in Descartes Meditations on First Philosophy. This fallacy is called the Cartesian Circle in reference to Descartes apparently circular reasoning that he can have clear and distinct ideas because of God’s existence, but that the proof of God’s existence and is itself based on clear and distinct ideas. Gewirth’s response to critics of Descartes is that Descartes use different types of certainty to prove the existence and veracity of God compared to accuracy of clear and distinct ideas. The latter of these types of certainty, metaphysical certainty, is what he focuses on in The Cartesian Circle Reconsidered. Gewirth details three interpretations of why simple propositions are susceptible to metaphysical doubt: operational, conceptual, and ontological. His argument is that Descartes only means ontological doubt in the Meditations. However, while his arguments for this and against the conceptual interpretation are strong, his claim that the operational interpretation is weak is not as reasonable.
The operational interpretation claims that the potential doubt of simple propositions stems partly from a deception in the operation of memory on previous intuitions rather solely the intuitions themselves. Descartes himself says something to this effect this in meditation three,
“When I consider the nature of the triangle, it appears very clearly to me… that its three angles equal two right angles, and I cannot help believing this to be true as long as I attend to the proof; but as soon as I turn my mental gaze elsewhere, even though I may remember that I perceived it clearly, I can easily doubt whether it is true, if I am still in ignorance of God” (Descartes 60).
Gewirth claims that this is not the most basic or complete interpretation of Descartes’ metaphysical doubt. Although he recognizes that this interpretation does have textual support, as evidenced by the above quote, he believes that this is not the only metaphysical doubt that Descartes holds (Gewirth 671). Indeed, this interpretation does not get at the truth of the intuition itself as it is perceived, but rather in the time that follows.
However, it would seem that Gewirth then contradicts himself in part of his reasoning for why possible errors cannot lie only in memory. He claims that, “intuitional certainty consists in the mind immediate and unfailing sent to, or belief in the truth of, whatever it intuits or directly perceives clearly and distinctly,” implying that it is metaphysical rather than intuitional doubt that covers failures of memory (Gewirth 672). In doing this it seems that he acknowledges Descartes’ inclusion of failures of memory in metaphysical doubt, and so also must include it in Descartes’ doubt of simple propositions. Even if this were not Gewirth’s intention, it would seem that a large portion of his...