How did Descartes fail to prove the existence of God?

Descartes' ontological (or a priori) argument is both one of the most fascinating and poorly understood aspects of his philosophy. Fascination with the argument stems from the effort to prove God's existence from simple but powerful premises. read more

Descartes' proof of the reliability of clear and distinct perceptions takes as a premise God's existence as a non-deceiver. Descartes' proofs of God's existence presuppose the reliability of clear and distinct perceptions. read more

Descartes gives at least two arguments for God's existence. The first one, found in I.14, is a version of the ontological argument for God's existence. Descartes' ontological argument goes as follows: (1) Our idea of God is of a perfect being, (2) it is more perfect to exist than not to exist, (3) therefore, God must exist. read more

From this we can derive at the possibility that God may be imperfect, and this is a contradiction to Descartes’ argument of God as a perfect being. In the ” Meditation Five,” Descartes attempts to prove his hypothesis of the existence of God based on the theory of clarity and distinctness of perception. read more