Why Does Descartes Say That Nothing Can Ever Be Known Perfectly Without a Knowledge of God? Is It True?

In this essay I will outline why Descartes has come to the conclusion that we cannot be perfectly certain of any knowledge without firstly realising God must exist and I will reject this notion on the grounds that God’s existing will not affect the certainty of things which we cannot doubt.
Firstly I shall address why Descartes supposes we must have knowledge of God before we can know anything with perfect certainty. Descartes believes that he, unlike an atheist, can have absolute certainty of the things he perceives clearly and distinctly in his mind since the existence of God, the most perfect being, strengthens his conviction that he need not doubt this type of knowledge. Although without knowledge of God we can believe things to be certain, according to Descartes, a lingering doubt remains as to whether nature could have made us in such a way that we are mistaken in our greatest assurances, and consequently we can never know anything perfectly. Essentially, without God, we can doubt any knowledge we possess as there always remains the possibility that the faculties of the mind we have inherited are fundamentally unreliable. In his Fifth Meditation Descartes states: ‘once I perceived that God exists and have also understood...that he is not a deceiver, I concluded that all those things that I clearly and distinctly perceive are necessarily true’ (René Descartes, Fifth Meditation from Desmond M. Clarke, ‘Meditations and Other Metaphysical Writings’, pg 56). It seems here that due to God’s nature as the perfect and benevolent creator, He would not have given us the capability of understanding simply so that we would be mistaken in even the most convincing of our beliefs. It’s this notion that gives Descartes a higher level of certainty in his form of knowledge and allows him to be able to know something perfectly.
Whilst this argument may seem cogent; that any knowledge of God would surely reinforce prior true knowledge, Descartes fails to consider whether he...