René Descartes' "Proofs of God's Existence"

From "Meditations on First Philosophy"

Philosopher Descartes. Getty Images

René Descartes' (1596-1650) "Proofs of God's Existence" is a series of arguments that he posits in his 1641 treatise (formal philosophical observation) "Meditations on First Philosophy," first appearing in "Meditation III. of God: that He exists." and discussed in more depth in "Meditation V: Of the essence of material things, and, again, of God, that He exists." Descartes is known for these original arguments that hope to prove God's existence, but later philosophers have often critiqued his proofs as being too narrow and relying on "a very suspect premise" (Hobbes) that an image god exists within mankind.

In any case, understanding them is essential to understanding Descartes' later work "Principles of Philosophy" (1644) and his "Theory of Ideas."

The structure of Meditations on First Philosophy — who's translated subtitle reads "in which the existence of God and the immortality of the soul are demonstrated" — is fairly straightforward. It begins with a letter of dedication to "The Sacred Faculty of Theology in Paris," where he submitted it originally in 1641, a preface to the reader, and finally a synopsis of the six meditations that would follow. The rest of the treatise is meant to be read as if each Meditation takes place a day after the one prior.

Dedication and Preface

In the dedication, Descartes implores the University of Paris ("Sacred Faculty of Theology") to protect and keep his treatise and posit the method he hopes to ascribe to assert the claim of God's existence philosophically rather than theologically.

In order to do this, Descartes posits he must make an argument that avoids critics' accusations that the proof relies on circular reasoning. In proving the existence of God from a philosophical level, he would be able to appeal to non-believers as well. The other half of the method relies on his ability to demonstrate that man is sufficient to discover God on his own, which is indicated in the Bible and other such religious scriptures as well.

Fundaments of the Argument

In preparation of the main claim, Descartes discerns thoughts could be divided into three kinds of operations of thought: will, passions and judgment. The first two cannot be said to be true or false, as they do not pretend to represent the way things are. Only among judgments, then, can we find those sorts of thoughts representing something as existing outside of us.

Next, Descartes examines his thoughts again to discover which are components of judgment, narrowing his ideas into three types: innate, adventitious (coming from the outside) and fictional (produced internally). Now, adventitious ideas could have been created by Descartes himself. Although they do not depend on his will, he might have a faculty producing them, like the faculty that produces dreams. That is, of those ideas that are adventitious, it might be that we produce them even if we do not do so willingly, as it happens when we are dreaming. Fictional ideas, too, could have clearly been created by Descartes himself. Of those, we are even aware of having come up with them. Innate ideas, though, beg the question of where did they originate?

For Descartes, all ideas had a formal and objective reality and consisted of three metaphysical principles.

The first, nothing comes from nothing, holds that in order for something to exist, something else must have created it. The second holds very much the same concept around formal versus objective reality, stating that more cannot come from less. However, the third principle states that more objective reality cannot come from less formal reality, limiting the objectivity of the self from affecting the formal reality of others

Finally, he posits that there is a hierarchy of beings that can be divided into four categories: material bodies, humans, angels and God. The only perfect being, in this hierarchy, is God with angels being of "pure spirit" yet imperfect, humans being "a mix of material bodies and spirit, which are imperfect," and material bodies, which are simply called imperfect.

Proof of God's Existence

With those preliminary theses at hand, Descartes dives into examining the philosophical possibility of God's existence in his Third Meditation.

He breaks this evidence down into two umbrella categories, called proofs, whose logic is relatively easy to follow.

In the first proof, Descartes argues that, by evidence, he is an imperfect being who has an objective reality including the notion that perfection exists and therefore has a distinct idea of a perfect being (God, for example). Further, Descartes realizes that he is less formally real than the objective reality of perfection and therefore there has to be a perfect being existing formally from whom his innate idea of a perfect being derives wherein he could have created the ideas of all substances, but not the one of God.

The second proof then goes on to question who it is then that keeps him — having an idea of a perfect being — in existence, eliminating the possibility that he himself would be able to do. He proves this by saying that he would owe it to himself, if he were his own existence maker, to have given himself all sorts of perfections. The very fact that he is not perfect means he would not bear his own existence. Similarly, his parents, who are also imperfect beings, could not be the cause of his existence since they could not have created the idea of perfection within him. That leaves only a perfect being, God, that would have had to exist to create and be constantly recreating him. 

Essentially, Descartes' proofs rely on the belief that by existing, and being born an imperfect being (but with a soul or spirit), one must, therefore, accept that something of more formal reality than ourselves must have created us. Basically, because we exist and are able to think ideas, something must have created us (as nothing can be born from nothing).