Abstract

In his reflections on the Cartesian philosophy Leibniz proposes that action rather than thought is the essence of the substance. The action of the substance consists not only in thought, but also in spontaneous motion. By means of this new criterion, Leibniz overcomes the Cartesian distinction between corporeal and spiritual substances. Moreover, he overcomes the Cartesian opposition between subject and object by emphasizing the intentionality of thought through the addition of the principle 'varia a me cogitantur' to Descartes' 'cogito, ergo sum'. In the course of this paper the main characteristics of the monad - action, unity, perception, appetition, apperception - will be presented