Friday, October 19, 2007

A Summary of Descartes' Ontological Argument and a Consideration of the Kantian Critique

Of the various arguments for God, the ontological argument is the most intriguing. Though it has always engendered criticism even by those who accept its conclusion, it has been reformulated, reasserting itself again and again in different form. It has great appeal to theists because it is an a priori argument, one which is understood to be true analytically on its own terms without an appeal to experience. Because it does not depend on empirical findings, it – if it is valid – is absolutely certain. Furthermore, the argument intends to prove a supreme being, one which is good and omniscient, and not merely a vague “first cause.” We shall examine this argument as it is formulated by Descartes in particular, and examine the Kantian objection to it.

Anselm is credited as the first thinker to formulate the ontological argument, though earlier thinkers promulgated elements of it. His formulation was simple: God is that than which no greater can be conceived; it is greater to exist than to not exist; therefore God must exist. The very definition compels the acceptance of his existence. This frequently is noted to be peculiarly unconvincing; even when one grants the argument's validity it does not really seem to compel assent. St. Thomas Aquinas asserts in the Summa that the existence of God is not self-evident, we can argue for his existence only a posteriori. Consequently, he questioned the way in which the argument defines God, noting that not all people define God in the same way. Further, the argument proves only God's “mental existence” not his actual existence. Here he is all too brief, but what he is getting at is probably the same sort of thing that Kant says more extensively; Thomas just didn't have a sufficient philosophical apparatus. A monk named Gaunilo dealt with Anselm's argument more thoroughly. He attempts a reductio by positing the perfect island. It is more perfect to exist than not to exist, and therefore our perfect island must exist. His intention was to demonstrate that the type of move from conceptual reality to tangible reality that the ontological argument makes is unjustifiable. The criticism that the ontological argument inappropriately moves from definition to reality was regarded as convincing, and the argument lost much of its influence.

Descartes resurrects the argument, and his reformulation of it is central to his system. He claims, at the beginning of the Meditations, that his purpose is to demonstrate that the knowledge of God is more certain than the knowledge of corporeal things. His ontological argument cannot be understood without reference to his philosophical method in the Meditations.

The Meditations is one of the most influential works of philosophy, and is the beginning of the modern era of philosophy. In it, Descartes invites his readers to participate with him in a thought experiment in order to discover what is absolutely certain, and to rid oneself of error. Descartes uses the method of hyperbolic doubt to discover the absolute foundation of truth: that one truth which cannot be doubted. He finds that he can doubt sensory experience and even the reflexive truths of mathematics, but he cannot doubt that he is doubting. Elucidating further, he may be deceived about everything, but he cannot be deceived about the fact that he exists. One cannot be deceived unless one exists. Cogito ergo sum. Here Descartes finds his epistemological foundation from which he can build the entirety of his philosophy. Having found something beyond doubt, he can now expand to other certain truths.

In order to get out of his self-imposed solipsism, Descartes must prove that a good God exists. Otherwise, some evil genius may be deceiving him even when he asserts mathematical truths. Thus, the second step after he is to prove the existence of God. Before he does this, he begins to organize his ideals, to find which thoughts may err and which may not. Strictly speaking, ideas in themselves are not true or false. It is only when the added step of judgment is performed that the potentiality for error arises. For example, the idea of a centaur is neither true nor false. The positive judgment that a centaur exists is false. But why do we believe that our ideas come from some analogous thing in the world? Descartes says that it is nature that compels us to believe this.i The natural belief that our mental representations of things come from without is quite compelling—especially when one considers that some of these ideas are not the sorts of things that we would create voluntarily. The world we perceive is certainly not the world we would create, and it seems reasonable to suppose from this that the world is not generated by us. At this point Descartes distinguishes between what he has a natural impulse to believe, and what is revealed to us by the “natural light.” What we have an impulse to believe – that external bodies exist, for example – is open to doubt. What is revealed by the natural light is not open to doubt.ii “This is because there cannot be another faculty both as trustworthy as the natural light and also capable of showing me that such things are not true.”iii After this point, Descartes uses what is revealed to him by the natural light as certain. Yet this is little more than sheer assertion. Until the existence of a good God is demonstrated, Descartes' method required us to doubt even truths which asserted themselves so strongly that doubting them seemed absurd.iv Descartes suspends his method of hyperbolic doubt for these truths, probably because they are necessary to demonstrate the existence of God and escape solopsism.

Meditation 3 is devoted to proving the existence of God. In the first and longest proof Descartes maintains that the idea of God is of such a nature that we could not generate it from ourselves, rather it must come from God because he is the only being great enough to bring about such an idea. This argument will not be dealt with in depth in this essay, except to note that it presupposes a relationship between ideas of things and things themselves which is entirely tenuous. Descartes next uses a form of the cosmological argument to demonstrate a “first cause.”

In Meditation 4 Descartes attempts to establish a more distinct method for determining truth and falsity. He declares that he has proven the existence of a God that would not engage in deceit and that gave him his faculty of judgment, ensuring that if it were used properly it would function without error. Yet Descartes did not gain any ground in Meditation 3. He was already using his faculty of judgment as if it functioned properly, if in a limited way, and he had previously dodged the question of whether an evil genius could deceive him even in things he regarded as most certain (i.e., what is revealed by the natural light). So in a way, Descartes position in Meditation 5 is not all that different from his position in Meditation 3.

The ontological argument is dependent upon the proposition that whatever one clearly and distinctly apprehends is true. The summary above should make it evident that this premise should itself be justified by the existence of God (a God that does not deceive). Here Descartes can be accused of circular reasoning: whatever is clearly and distinctly perceived is true because a good God would not make us in such a way as to be deceived in simple things, and we know a good God exists because of our clear and distinct perception. Whether or not the accusation is true is incidental to our purpose in this essay. However, it is significant to note that, whatever the order of reasoning between the truth of the clear and distinct and the existence of God is earlier in the Meditations, if these two things are inextricably related then the ontological argument is superfluous. The ontological argument requires one to assume the principle of clear and distinct truths, and at this point in the meditation Descartes has demonstrated this by already proving the existence of God. Though his principle of clear and distinct truths and his proofs for God perhaps do not meet the high standard for certainty set out in Meditation 1, this does not mean that they are useless. An argument for the existence of God which is as certain as the truths of mathematics is certainly a sufficient one.

Here is Descartes' ontological argument for the existence of God:
But if the mere fact that I can produce from my thought the idea of something entails that everything which I clearly and distinctly perceive to belong to that thing really does belong to it, is this not a possible basis for another argument to prove the existence of God? Certainly, the idea of God, or a supremely perfect being, is one which I find within me just as surely as the idea of any shape or number. And my understanding that it belongs to his nature that he always exists is no less clear and distinct than is the case when I prove of any shape or number that some property belongs to its nature. Hence, even if it turned out that not everything on which I have meditated in these past days is true, I ought still to regard the existence of God as having at least the same level of certainty as I have hitherto attributed to the truths of mathematics.
The ontological argument is first presented as an analogy. I distinctly perceive in the idea of a triangle that it has three sides, and that the largest side is opposite the widest angle. Therefore, this inherently belongs to the triangle. So it is with God. I distinctly perceive in the idea of God that he necessarily exists, and I perceive this just as clearly as I perceive the geometrical properties of a triangle. An initial criticism might be that an analogy is not an argument: what holds true with a triangle, which exists only conceptually, may not be true of an existing being. Descartes anticipates something along these lines. He is aware that one is to distinguish existence and essence in things, yet in God, he argues, there is no such distinction. Therefore, when one understands God's essence, he understands his necessary existence.

Descartes was probably aware of the criticisms directed at Anselm, and was careful to point out that in his formulation of the argument a definition was not “imposing” reality on things: “But from the fact that I cannot think of God except as existing, it follows that existence is inseparable from God, and hence that he really exists. It is not that my thought makes it so, or imposes any necessity on any thing; on the contrary, it is the necessity of the thing itself, namely the existence of God, which determines my thinking in this respect.” Here Descartes is further emphasizing the unique relation between God's essence and his existence. Guanilo directed a reductio ad absurdum against Anselm in which he asks his readers to imagine the most perfect island. The most perfect island must exist since to not exist impinges upon its perfection. Guanilo's point is that existence cannot be arbitrarily inserted into a definition. Descartes avoids this by saying that part of Gods essence is to exist necessarily, and this feature he does not share with created things. God's special fusion of existence and essence is what makes the ontological argument work. When one grasps his essence, one grasps the necessity of his existence.

Descartes' argument can be understood as being based upon a fundamental intuition. Instead of merely arguing from premises, he was primarily relating an encounter with the concept of God. By simply understanding the concept of God, he understands the existence of God prior to any of the methodological content or formal arguments of the Meditations. Descartes is not convinced by an argument, but by an experience. “But whatever method of proof I use, I am always brought back to the fact that it is only what I clearly and distinctly perceive that completely convinces me.”v While this experience is not of the same kind as one experiences sunlight or a tree, being rather a rational exercise, it is a direct rational exercise (rather than a rational exercise directed at something external), and one in which understanding necessitates consent.

The definitive critique of the ontological arguments is generally considered to be that of Immanuel Kant. In his Critique of Pure Reason he examined a priori reasoning and attempted to establish its limits. In the course of this work, he determined that the ontological argument was invalid, an example of a priori reasoning attempting to go beyond its limits. Kant inquired into what it is that makes the existence of a being necessary by virtue of its definition, or more precisely what prohibits one from asserting the non-existence of a necessary being. If, in our examination of the idea of something, we find that it necessarily includes existence, does this add anything to the concept? Or is this saying nothing at all?

Kant takes up the analogical form of the ontological argument:
Thus the fact that every geometrical proposition, as, for instance, that a triangle has three angles, is absolutely necessary, has been taken as justifying us in speaking of an object which lies entirely outside the sphere of our understanding as if we understood perfectly what it is that we intend to convey by the concept of that object.” All the alleged examples [such as the triangle] are, without exception, taken from judgements, not from things and their existence. But an unconditioned necessity of judgments is not the same as an absolute necessity of
When we speak of a triangle as necessarily having three angles, we are referring not to whether it exists or not, nor the manner of its existence, but to its definition alone. If a triangle exists, then it has three angles. This is not derived by a posteriori considerations, but by virtue of the definition of the triangle, and nothing else. When something is true by its definition, it is true analytically, and is metaphysically certain. Kant continues, “The above proposition does not declare that three angles are absolutely necessary, but that, under the condition that there is a triangle (that is, that a triangle is given), three angles will necessarily be found in it.” It does not follow that because a triangle has three angles, that three angles must exist, only that if a triangle exists, it has three angles. The definition of a thing does not necessitate anything actually existing in reality. Here we see something akin to Hume's fork: a strong distinction is made between the analytic a priori of the definition and the synthetic a posteriori of a thing's actual existence. This distinction must be erased in order for the ontological argument to work, because it acts as a barrier preventing one from moving from definition to reality.

The ontological argument requires that when one posits the definition of God, one also posits his existence. The idea of the ontological argument is that we contradict ourselves if we deny God's existence (though this is more ambiguous in Descartes' formulation). But Kant points out that though we contradict ourselves if we say a triangle does not have three sides, we do not contradict ourselves if we reject the triangles necessary attributes, we reject the triangle as well. The same holds true of God. “If its existence is rejected, we reject the thing with all of its predicates; and no question of contradiction can the arise.”vii

Kant further maintains that there is an internal contradiction in inserting existence into a concept:
We must ask: Is the proposition that this or that thing... exists, an analytic or a synthetic proposition? If it is analytic, the assertion of the existence of the thing adds nothing to the thought of the thing; but in case either the thought, which is in us, is the thing itself, or we have presupposed an existence as belonging to the realm of the impossible, and have then, on that pretext, inferred its existence from its internal possibility—which is nothing but a miserable tautology.viii
Existential propositions cannot be analytic, for either they would not allow a distinction between a thought and its object, or they would amount to tautologies as the predicate is already posited in the subject. Therefore, existential propositions must be synthetic. But if this is the case, then it is possible to deny “God exists” without contradiction. Kant is not content to end his criticism here.

Kant examines the syntax of what it means to say something “is:”
The proposition “God is omnipotent” contains two concepts, each of which has its object—God and omnipotence. The small word “is” adds no new predicate, but only serves to posit the predicate in its relation to the subject. If, now, we take the subject (God) with all its predicates (among which is omnipotence), and say “God is,” or “There is a God,” we attach no new predicate to the concept of God, but only posit the subject in itself with all its predicates, and indeed posit it as being an object that stands in relation to my concept. The content of both must be one and the same; nothing can have been added to the concept, which expresses merely what is possible, by my thinking its object (through the expression “it is “) as given absolutely. Otherwise stated, the real contains no more than the merely possible.ix
Though the earlier stages of Kant's refutation appear to me more oriented toward Anselm's version of the ontological argument, here Kant seems to have Descartes in mind. Adding existence (necessary or otherwise) to the concept “God” does not actually add anything at all conceptually. To say something exists is to say something about the object of a concept, not the concept itself. To further elucidate this point, Kant asks us to consider the difference between a hundred real thalers (a coin) and a hundred possible thalers. Though these make a difference materially, there is no ideal difference between the two.
For as the latter signify the concept, and the former the object and the positing of the object, should the former contain more than the latter, my concept would not, in that case, express the whole object, and would not therefore be an adequate concept of it... For the object, as it actually exists, is not analytically contained in my concept, but to my concept (which is a determination of my state) synthetically; and yet the conceived hundred thalers are not themselves in the least increased through thus acquiring existence outside my concept.x
Existence, therefore, cannot be contained analytically in a concept, but is a synthetic addition in which we must distinguish between concept and object. Kant's argument as a whole is certainly damning for Anselm's ontological argument, because Anselm intends to demonstrate that one who denies God contradicts himself. Kant's careful analysis reveals this as clearly erroneous. But what of Descartes? Descartes' ontological argument is constructed to avoid some of the criticisms which were directed towards Anselm's. He does not argue from the definition of God, accusing his opponents of self-contradiction. He deals instead with the idea of God, which he clearly and distinctly perceives. Once one perceives the idea of God, which contains necessary existence, assent is compelled. It is here that Descartes is vulnerable to the Kantian critique: necessary existence is not present in an idea, for it adds nothing to the idea analytically, and God and his predicates can be denied to exist entirely.

iRenee Descartes, “The Meditations,” in The Philosophical Writings of Descartes: Volume 1, trans. John Cottingham, Robert Toothoff, and Dugald Murdoch (Cambridge: Cambridge University Press, 1984) 26.
iiDescartes, 27.
iiiDescartes, 27.
ivDescartes, 14-15.
vDescartes, 28.
viImmanuel Kant, “Critique of Pure Reason,” in The Existence of God, ed. John Hick (New York: The Macmillen Company, 1964), 41.
viiKant, 42.
viiiKant, 43
ixKant, 44.
xKant, 44.

1 comment:

J M Hart said...

Hey thanks so much for posting this, its exactly what I needed to help me with my homework! My teacher only spent five minutes explaining both of these subjects and then asked us to go away and give him an essay by the next lesson... I love you!