La natura semplice e l’idea

Abstract

The vocabulary of simple natures found in the Regulae disappears from the later works and correspondence of Descartes, who only know the vocabulary of the idea. Does this mean that these two notions are equivalent? We show that this is not the case. Simple nature derives its simplicity and its certainty from the unity of the intuitus which delimits it: what is known by the intuitus is certain only by the natural light in which the intuitus deploys and embraces it. This capacity specific to the mind to certify for itself that something is known with certainty, testifies to the fact that intuitus is certain insofar as it provides evidence, which frees it
from the possibility of error. This is not the case of the idea as a perception of the understanding, which as such cannot itself ensure its own certainty, since it returns to the will to do within the framework of the theory of judgment. The idea, as a perception of the understanding, can contain, in principle, falsity and it is precisely against this possibility that the faculty of knowing must guard itself in the use of judgment. The abandonment of the vocabulary of simple natures in favor of that of the idea testifies to this new position which is imposed on Descartes due to the theory of the creation of eternal truths formulated in the letters to Mersenne of 1630 and correlatively, of the set of conditions involved in determining the essence of truth as a certainty not yet understood in the text of the Regulae.