Doubt and certainty › What the Meditations Leaves Open

The book offers a sequence of arguments rather than a single maxim about thinking. It moves from doubt, to the thinking self, to God, to the explanation of error, and finally to bodies and the union of mind and body. At each stage, the reader can ask both what the argument claims and whether its reasons are sufficient. The most useful disagreement is specific. Does the causal principle governing ideas hold? Is necessary existence a feature that a concept can establish? Does the appeal to a non-deceiving God secure the passage from sensory experience to bodies? Can the real distinction between mind and body be reconciled with their union? These are the questions the preceding arguments put on the table. Return to the opening experiment with those distinctions in mind. Something can survive an attempt to doubt it without settling every question about its nature. Descartes' first certainty starts the inquiry; it does not complete it.