In his conversation with the young Dutch scholar Frans Burman in 1648, Descartes expressed his expectations about the future treatment of his metaphysical writings: “A point to note is that one should not devote so much effort to the Meditations and to metaphysical questions, or give them elaborate treatment in commentaries and the like. Still less should one do what some try to do, and dig more deeply into these questions than the author did; he has dealt with them quite deeply enough” (CB 48 = AT v 165: CSMK 346–47).

In the process of writing this book, I found myself recurrently wondering whether I was not acting against Descartes' expressed wish. Though I would certainly not credit myself with the sin of digging into Descartes' metaphysical questions more deeply than he had himself, I may have failed to comply with the first half of his wish. Fortunately, though, I am not alone in committing this sin, and we can only speculate about what the father of modern philosophy would have thought and felt had he been acquainted with the huge interpretive enterprise that his tree of philosophy has yielded. Three hundred and sixty years after Descartes' death, and despite the enormous wealth and diversity of interpretations that have since become available, the possibility of revealing new layers and striking perspectives in his thought was an exciting discovery in the course of my writing.