What Descartes Did Not Know

According to Descartes, we come to know about the mind and the body as separate substances by way of philosophical meditation, while we see that mind and body may interact as a union by ‘‘using only life and ordinary conversation’’ and ‘‘abstaining from meditating.’’ What is significant, indeed, far more significant than has been appreciated by commentators so far, is that we, thereby, are supposed to answer what has come to be considered one of the most central questions of Descartes’ philosophy, the question ‘‘How do minds and bodies interact?’’, not by way of Descartes’ official method of meditation through methodological doubt and clear and distinct perception, but by explicitly acting against the recommendations of this method. Since meditation is supposed to provide an unshakeable epistemic foundation for claims to knowledge, this raises the question whether there is any sense in which we, on Descartes’ view, can be said to know anything about the mind-body union.