“Compare, contrast and evaluate Descartes’ and Leibniz’s arguments for the existence of ”

Descartes and Leibniz are two key philosophers whose contributions in various areas influenced much of our modern thinking. Particularly with reference to religious philosophy, we see that both Descartes’ and Leibniz’s contributions have greatly influenced the area of philosophy devoted to proving the . While

Descartes’ provides us with two different proofs for God’s existence, Leibniz evaluates and modifies one of Descartes in order to safe proof it from its earlier criticisms.

Descartes’ two arguments for God’s existence: the trademark argument, and the , can be found in his Meditations 3 and 5 respectively. The trademark argument (Nigel Warburton, Philosophy: The Classics, 2nd edition) is called as such because it is as if God left as a trademark on his creation (man) the revelation of His existence. That is, the innate idea of God is like a trademark stamp. The argument relies on this innate idea, and then applies the Causal Adequacy Principle(Nigel Warburton,

Philosophy: The Classics, 2nd edition), which states that the cause must contain all attributes of the effect, if not more. Descartes begins by stating that he has doubts and desires, which proves that he is a deficient and imperfect being. He continues to assert that it would be impossible to understand deficiency and imperfection without the idea of perfection to use as a base of comparison. By proving that he has the idea of perfection, he can begin his argument for God’s existence. Descartes argues that, because he has the idea of perfection, the idea must have a cause (because something cannot come from nothing). By applying the Causal Adequacy Principle to ideas, he asserts that the cause of the idea of perfection must have as much perfection as the idea itself. But since he’s

1 already established that the idea of perfection could not have come from him, as he is imperfect, it follows that the idea must have come from God. As he states “it is no surprise that God, in creating me, should have placed this idea in me to be, as it were, the mark of the craftsman stamped on his work” (Descartes, Meditations on First Philosophy

(Meditation 3)). This allows Descartes to conclude that God is perfect, and cannot be a deceiver (because deception entails imperfection) which means that God would not create beings in which that which seems clear and distinct is actually false. Therefore, Descartes can trust his clear and distinct ideas, and since he has a clear and distinct idea of God,

God must exist. Essentially, Descartes is saying that we have an idea of God, who is an infinite and perfect being; that idea couldn’t have been caused by anything lesser (than an infinite, and perfect being) and so God must have caused the idea of himself within is; If

God caused the idea, then he must exist in order to do so.

But herein lies the greatest flaw in the argument: in order to know our idea of God is clear and distinct, we need to know that God exists (and isn’t a deceiver). So we find ourselves trapped in a Cartesian Circle (Nigel Warburton, Philosophy: The Classics, 2nd edition), where what we perceive is true because God exists, but we can only be sure that

God exists because we perceive it to be true. Another problem arises when we consider the application of the Causal Adequacy Principle which serves essentially as the fulcrum of Descartes’ argument. Firstly, why does Descartes assume that the principle can be applied to ideas? The Causal Adequacy Principle is used to describe affects of the physical world. But since Descartes is a dualist and believes that the physical and mental are two different realms, it appears as though he is severing that distinction merely for the purposes of making his argument more plausible. Even if we do apply the principle to our

2 ideas, we reach another criticism: why do all our ideas need a cause? Moreover, why do these ideas impose necessity: Surely to have an idea of something (for example, a perfect island) does not dictate that it is necessary for this island to exist, or that it does exist at all. Secondly, as pointed out by Cottingham (John Cottingham, Descartes), the principle doesn’t allow for objects to be “greater than the sum of its parts”. Cottingham uses the example of a sponge cake: the property of “sponginess” that the cake gained during its baking was not present in its ingredients (the eggs, flour, sugar, etc.), so where did the cake get its characteristic “sponginess” from? A broader example can be seen in evolution. Science has proven that life evolved from inanimate matter (the elements effecting the earth), and so in this sense, animate life was caused by something lesser than itself. Another obvious criticism of Descartes argument is its founding assumption that everyone has within them the clear and distinct idea of God. Could this idea we all have not simply be derived from early indoctrination? Essentially, Descartes has erred in making his argument too specific: instead of asking “Why is there something rather than nothing?” (the ) he asks “Where does my idea of God come from?”

In the Ontological argument, Descartes states that because God is a supreme and perfect being, it would be an imperfection to not exist, and therefore in his very concept

God proves that he necessarily exists. Since we have the idea of God in our minds, to exist within the mind solely is less perfect than to exist within the mind and reality, so

God must exist in reality because his very nature is perfection. Descartes fortifies his argument by explaining that we can conclude truths regarding objects from the very ideas of them. For example, from the idea of a triangle we can conclude that its angle’s add up

3 to 180 degrees. It follows that if we can conclude truths, then they are both possible and actual: therefore from the idea of God as a perfect being we conclude that it is possible and actual that God exists. For something to be possible it is true in some possible world, but for something to be necessary it is true in every possible world, including the actual.

That is to say, it would be a limit for God to exist in some possible world and not every possible world (for him to possibly exist), and since God is a limitless being, he must exist in every possible world (necessarily exist).

But this argument is not without its flaws. The same Cartesian circle that exists in the Trademark argument is also found within the Ontological one, as it depends on having a clear and distinct idea of God, which would only be possible if God existed in the first place. The argument clearly attempts to define God into existence, which is nothing more than a logical trick. Again, Descartes assumes that thoughts impose necessity, and so by conceiving of God, he must exist to validate his perfect conception.

It could be argued that an unlimited being should not require necessity: surely as a characteristic of being unlimited, He should depend on nothing to cause his existence.

The greatest problem with Descartes Ontological argument is the assumption that existence is a property. Properties are modifiers of the subject, which can only occur when the subject is already in existence. Therefore existence cannot be a property, as it is still used to modify the subject even if the subject doesn’t exist. Essentially, “existence” is the condition of a subject, on which properties depend. That is, if something exists, we can then define it to have properties such as height, colour, characteristics, etc. But these properties are only true if the object exists. If the object does not exist, we define it no

4 further than saying it does not exist (we do not give it height, colour, characteristics, etc.).

This means that existence continues to modify the subject regardless of its state of being, where as properties do not.

Leibniz had his own thoughts and criticisms of Descartes, despite following in a similar vain with his proof of God’s existence. Leibniz thought that to prove God’s existence first it must be proved that he is possible, since when rationalized, properties of

God contain contradictions. Leibniz states “I know what being is, and what it is to be the greatest and most perfect, nevertheless I do not yet know, for all that, whether there isn’t a hidden contradiction in joining all that together.. In brief, I do not yet know, for all that, whether such a being is possible” (Leibniz, letters to Foucher, to Elizabeth, and to

Molanus, p.91, Modern Philosophy, an Anthology of Primary Sources). Leibniz thought that Descartes arguments were based on the presumption that God is possible merely because of a clear and distinct idea, but that essentially, Descartes offered no further proof. Through his criticisms of Descartes, Leibniz creates his own argument for God’s existence. Whilst Descartes’ believed that if we can clearly and distinctly conceive of something, then it is known and actual; Leibniz asserted that if something is logically consistent, then it is possible. By eliminating Descartes’ dependency on “clear and distinct ideas” Leibniz manages to save himself from the Cartesian Circle. He explains that in order for there to be a logical inconsistency in God’s concept, there must be a contradiction, which requires both an affirmation and negation of the same property. He then defines God as a being that necessarily has all positive properties. He continues to explain that positive properties are those which cannot be further analyzed, and are at

5 their simplest form. Since he believes that something is possible if it contains no contradictions, he applies that by explaining that simple properties, by their very nature, cannot contain contradictions. Since there are no contradictions in the concept of God, He is logically consistent, and therefore exists. For example, God is infinite because to be finite is to have a limit, or negation. Evil and are negations of positive properties, which can be further applied to created beings. Since we are finite, and to be finite is to have a negation, then we have evil and sin. But Leibniz’s argument is perhaps too simplistic. Whilst he is correct in asserting that simple properties don’t individually contain negations, once they combine to form God’s complete concept they cease to be simple, and can contain contradictions. An example of this is the simple property of “All

Light” combined with the simply property “All Dark”. If God is everything, he is both

“all light” and “all dark”, simultaneously, which is clearly a contradiction. This can be further applied to God’s ability to be “all merciful” whilst “all just”, or “omniscient” whilst “omnipotent” (if God is all knowing then he can foresee our chosen paths, but if he is all powerful then he grants man the free will and ability to create his path). Lastly, the same criticism that was placed on Descartes’ also applies to Leibniz: possible existence does not entail or impose necessary existence, since we can conceive of things that are logically consistent, and yet do not actually exist.

To conclude, both Descartes and Leibniz have put forth strong argument’s for

God’s existence. Leibniz’s must be commended as it avoids the traps and shortcomings that are evident in both of Descartes’. Whilst both arguments have their shortcomings,

Leibniz’s, though being an argument of logic and semantics, is stronger than Descartes in

6 its mere simplicity. By reducing his argument to definitions he avoids the caveats that slow Descartes’ to circumlocutory assumptions. Essentially, Descartes’ arguments, whilst being a good stepping stone, are the foundation on which a more plausible argument for

God’s existence could develop.

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