The Cartesian Circle

Descartes’ Cartesian Circle

Descartes’ “Cartesian Circle” has come under fire from countless philosophers because it supposedly commits a logical fallacy with its circular reasoning. In his second Meditation, Descartes attempts to prove the existence of God. He states that clear and distinct perception leads to knowledge, and that God’s existence is apparent and obvious because of things we have come to perceive as knowledge. Furthermore, he asserts that we cannot turn these perceptions into knowledge without the assurance that God exists. Essentially, Descartes claims that God is a necessary condition for knowledge, which in turn requires the existence of God. This circular logic presents a problematic scenario similar to the “chicken or the egg?” debate and has left philosophers pondering its legitimacy for decades.

As is usually the case when someone makes a bold and illogical statement, many have challenged Descartes’ logic. Many have claimed that his argument follows a “vicious circle,” as both premises rely on each other’s truth and validity. His argument is basically dependent on certainty of God’s existence, despite an equal amount of uncertainty regarding that existence. Descartes states that no one is definite about the existence of God, nor can they know anything clearly and distinctly until they are certain about the existence of God. Assuming that these premises are accurate, we as humans know nothing because we cannot say with certainty that God exists.

At first glance, it seems that Descartes has blatantly committed a logical fallacy, leaving his argument entirely defenseless. However, if it were be possible to disprove one of his two premises, any notions of circularity would be dissolved, legitimizing Descartes’ proof. The first defense takes a deeper look into Descartes’ writings in order to disprove his first premise, that God is an essential and necessary component for the formation of knowledge from a perception.

Some emphasize that Descartes never states God’s existence be necessary to turn a perception into knowledge, and is necessary only in the formation and preservation of memory about this knowledge. In one publication James Van Cleve writes about a philosopher named Willis Doney who advocates a “solution” to the Cartesian Circle called the Memory Gambit. Doney’s analysis reveals that “Descartes says that if I remember clearly and distinctly perceiving something that I do not now clearly and distinctly perceive, I can be certain of it if and only if I know that God exists” (Cleve, 56). Doney proposes that an atheist can learn and ascertain knowledge about subjects such as math if he clearly perceives them at the time. Whether or not he retains that knowledge or is able to erase doubt regarding that knowledge is entirely dependent on his comprehension of God’s existence. Doney’s interpretation therefore is that the function of God is only to guarantee the accuracy of one’s memory, rather than regulate the transition from a perception to a piece of knowledge. In other words, without a certainty that God exists, one is merely “trapped in a moment,” and can only be certain of things perceived at any one given time. By denying one of the premises that form the Cartesian Circle, it is possible to circumvent the logical fallacy originally committed.

Following in the steps of the first defense is one that seeks to disprove Descartes’ second premise: