What is really behind Descartes’ famous doubt?

Introductory university courses in philosophy often cover Rene Descartes (1596-1650). Descartes’ enduring popularity stems in part from his openness about the reality of disagreement and his struggles to resolve it. “Philosophy,” he once wrote, “has been pursued for many centuries by the best minds, and yet everything in it is still disputed and hence doubtful” (Discourse on Method). Young people often encounter serious intellectual diversity and disagreement for the first time on their college campuses, so they easily relate to Descartes’ struggles.

In his master work Meditations on First Philosophy, Descartes focuses not on disagreements between people, but on the ways in which he disagrees with himself. Descartes is capable to taking up more than one perspective on things, and these perspectives seem to conflict. When he thinks about something that he “clearly and distinctly” perceives — such as “2+3=5” or “I must exist since I am thinking” — he can’t imagine how such a thing could be false. But when he views himself from a theological perspective and thinks about the power of God, he can imagine how these things could be false: God could build him to feel utterly convinced by false claims.

In his Third Mediation, Descartes tries to overcome this clash of perspectives, and the self-doubt it provokes, by proving that God cannot be a deceiver.  But this introduces a new clash between theology and experience: a good God would not cause him to make mistakes, and yet he knows for certain that he has often gone wrong. In the Fourth Meditation, Descartes resolves this conflict by appealing to free will. God has given him perfect cognitive equipment. If he uses it correctly, he won’t go wrong. But how he uses it is up him, and he often uses it incorrectly. Instead of waiting for clear and distinct evidence to come in, he goes ahead and believes things that are uncertain. No wonder he is often wrong.

This solution raises lots of questions. Can we really decide whether to believe something? And what does Descartes mean by “free will”? This last question is especially pressing, because Descartes says some very puzzling, seemingly contradictory things about freedom. He says that believing freely means having “two-way” ability: we can go ahead and believe, or we can wait for more evidence to come in. But he also says that when we perceive something clearly and distinctly, we can’t help but believe it — and nevertheless believe it freely!

It might seem that Descartes has a self-contradictory notion of freedom. But he really doesn’t. Descartes is working with a perfectly plausible notion of freedom. He thinks that freedom is the ability to do the right thing. When he perceives the truth of a claim with utmost clarity, he must believe it, and that is the right thing for him to do. But when a claim is sort of obscure, when there is evidence both for and against it, Descartes can either believe it, or not. The right thing is to wait for more evidence, and since he can do it, he is free. But he often is impatient and does the wrong thing.

The real trouble for Descartes’ escape from self-doubt is not his notion of freedom, but his belief in divine providence.  Descartes thinks that every choice we make fulfills a divine plan established from before creation. Things must go according to God’s plan. Therefore, it seems that when we make wrong choices, we weren’t really able to do the right thing after all, and so aren’t free (as Descartes defines freedom). Descartes “solution” to this problem is an appeal to mystery: somehow, God can leave our bad free choices undetermined, even though it is certain that we will make them. In effect, Descartes tells us that we simply have to live with a clash between theology and experience: when we think of God, we realize God must be in control of everything, but when we think of ourselves, we know that we are often free. Somehow, both claims must be true despite the clash.

Insofar as Descartes’ philosophical project is an attempt to overcome self-doubt, it does not seem successful. His original reason for self-doubt was a clash between theology and experience. It is hard to see why, if this clash gave him good reason to doubt himself, the clash between providence and freedom would not do so as well. In the end, he seems to disagree with himself about the ultimate lessons to learn from disagreement!

Featured image credit: Portrait of Rene Descartes, by Frans Hals. Public domain via Wikimedia Commons.