On Why Descartes Never Completed the Regulae ad directionem ingenii

This article addresses the following question: why did Descartes leave the Regulae unfinished? I argue that the answer lies in his Doctrine of 1630 on the creation of eternal truths. This theory laid the groundwork for a metaphysical shift that required a complete rethinking of the very foundations of his epistemology. This does not mean, however, that Descartes abandoned the project outlined in the Regulae. Rather, he needed to explore the premises of his theory to better assess its implications. The outcome of this long reflection would eventually be the Meditationes