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ONTOLOGICAL ARGUMENTS Ontology means “relating to being or existence”. Ontological arguments are different to other arguments for God’s existence, because they are a priori. Rather than starting from some sort of experience of the world, they rely solely on the definition of God. Ontological arguments claim that if you understand what the word God means, then you know that he exists, because existence is part of the definition of God. The proposition “God exists” is therefore analytic and is necessarily true. We will consider the first example of an ontological argument, put forward by St Anselm (1033-1109), the objections to it, and then how it has been modified by other philosophers up to the present day. Anselm’s Ontological Argument St Anselm was trying to write a single argument for God’s existence that didn’t rely on any other arguments or assumptions. His writing is in the form of a prayer addressed to God, but we can easily set it out in standard form. He starts from a definition of God: 1. God is that than which nothing greater can be conceived 2. It is greater to exist in understanding and in reality than in the understanding alone. 3. Therefore, God must exist in reality as well as in the understanding. If God only existed in our minds, then he wouldn’t be God, because there is something greater than an idea of God- actual God. So as long as we have a concept of God, and that concept involves being the greatest, then God must exist in reality. Philosophy of Religion 5: Ontological Arguments Page 1 Gaunilo’s Criticism of Anselm Shortly after Anselm’s first argument was published, another monk named Gaunilo wrote this reply: “It is said that somewhere in the ocean is an island…and they say that this island has an inestimable wealth…it is more excellent than all other countries…Now if someone should tell me that there is such an island, I should easily understand his words… But suppose that he went on to say…’since it is more excellent not to be in the understanding alone, but to exist both in the understanding and in reality, for this reason, the island must exist’.” Gaunilo is pointing out that Anselm’s reasoning can be used to prove that anything exists, as long as we claim it is the greatest or the most excellent. But we don’t think that these things must really exist. So we can’t rely on this reasoning to work for the existence of God. We need empirical evidence to prove that this most excellent island really exists, so we need similar evidence on which to base our belief in God. Anselm’s Response to Gaunilo In response to Gaunilo, Anselm claims that his reasoning only works for God. This is because everything else is contingent. Contingent things are limited and it is possible for them not to exist, so we don’t know if they exist until we check. But God is different, because his existence is necessary. We can imagine islands that don’t exist, because existence isn’t an essential part of being an island. But we can’t imagine God not existing, because it is an essential part of God that he exists. Philosophy of Religion 5: Ontological Arguments Page 2 Anselm can argue for this claim like this: 1. God is that than which nothing greater can be conceived. 2. A being which cannot be conceived not to exist is greater than one which can be conceived not to exist. 3. Therefore, God cannot be conceived not to exist. “That which can be conceived not to exist is not God” Since Anselm, many philosophers have proposed similar ontological arguments, and many others have criticised and discussed them: Descartes’ Ontological Argument 1. 2. 3. 4. 5. I have the idea of God The idea of God is the idea of a supremely perfect being A supremely perfect being has every perfection Existence is a perfection Therefore, God exists Descartes is saying that it is part of the concept of God that he exists. Triangle = 3 sides Unicorn = horse+horn God = exists Having three sides is part of the concept of a triangle. So it is impossible for a triangle not to have three sides. In the same way, existence is part of the concept of God, so it is impossible for God not to exist. God’s existence is necessary. Philosophy of Religion 5: Ontological Arguments Page 3 Leibniz’s Addition to the Ontological Argument Leibniz accepted Descartes’ argument, but felt that it was incomplete. Leibniz saw the potential for problems with a list of ‘perfections’. If we allow anything to qualify as being a perfection, we could end up with a set of perfections that are incompatible with each other (as we saw in handout R1). So Leibniz argued that a perfection must be simple and positive. That is, it can’t be defined in terms of anything else, and it can’t be defined as the negative of anything else. This means each perfection is selfcontained and doesn’t place a restriction on any other perfection, and therefore they couldn’t be incompatible with each other. So it is possible for the perfections to co-exist in one being. So a supremely perfect being is possible. So Leibniz’s ontological argument is the same as Descartes’, but with the addition of a premise: “A perfection is a simple quality which is positive and absolute”. ISSUES WITH ONTOLOGICAL ARGUMENTS Philosophy of Religion 5: Ontological Arguments Page 4 Hume’s Objection to Ontological Arguments As an empiricist, Hume thought that synthetic knowledge could only be gained through sense experience, not through reason alone. So any argument that attempts to prove a synthetic truth (that God exists) by using a priori reasoning should, using Hume’s fork, be disregarded. Anselm and Descartes seem to have been treating the proposition “God exists” as an analytic one. But Hume says that it must be synthetic, because it is making a claim about what really exists in the world. Hume continues: “Nothing that is distinctly conceivable involves a contradiction. Whatever we conceive as existent, we can also conceive as non-existent. There is no being, therefore, whose non-existence implies a contradiction. Consequently, there is no being whose existence is demonstrable.” Hume’s main point here is that because we can imagine God not existing, it is not contradictory to claim that he doesn’t exist. So his existence is not logically necessary, as Anselm and Descartes have claimed. Philosophical Skills… Most propositions consists of a subject and a predicate. The subject is what the proposition is about. The predicate gives us information about the subject. For example, in the sentence “the cat sat on the mat”, ‘the cat’ is the subject and ‘sat on the mat’ is the predicate. Philosophy of Religion 5: Ontological Arguments Page 5 Kant built on Hume’s ideas, putting forward two main criticisms: Kant’s First Criticism – existence is not a property of God “Existence is obviously not a real predicate.” Descartes and Anselm both assume that existence is a predicate. Kant says that real predicates add something to our concept, they give it new properties. But ‘existence’ doesn’t do this. Kant makes his point by asking us to imagine 100 Thalers (coins). We can imagine them being gold, round, heavy and old. These are all genuine predicates because they change our understanding of the coins. But if we then add “they exist”, nothing about our concept changes. There is no difference between the idea of ‘100 coins’ and ‘100 coins that exist’. So, ‘existence’ is not a real predicate. If Kant is right, then ontological arguments fail because they claim that existence is part of the definition of God. If existence is not a predicate then it can’t be part of the definition of God, or anything else. Kant’s Second Criticism – even if existence is a property of God, that doesn’t mean he exists In his second criticism, Kant temporarily accepts that existence is a real predicate, along with Descartes’ claim that “God necessarily exists” is an analytic statement. He argues that even if it is analytic, it doesn’t mean that God exists in reality. Philosophy of Religion 5: Ontological Arguments Page 6 For example, the definition of a unicorn is a horse with a horn. So it is necessarily true that unicorns have horns. Any unicorn that we ever encounter must have a horn. If it didn’t, it wouldn’t be a unicorn. But this doesn’t show that there are any unicorns in the world. All it shows is that if there are any, they will necessarily have horns. Kant says that the same reasoning applies to God. Necessary existence may be part of the definition of God. So we know that if God exists, then he exists necessarily. But this doesn’t tell us whether he does exist in reality. Descartes can define God however he likes. The definition can only ever tell us about our concept of God. Nothing in the definition can ever bridge the gap and tell us about what exists in the real world. Like Hume, Kant thinks only empirical evidence can do that. MODERN ONTOLOGICAL ARGUMENTS In recent years, several philosophers have tried to revive Anselm’s original argument. Two of these are Norman Malcolm (1911-1990) and Alvin Plantinga (1932- ). Philosophical Skills… If something is necessarily true, then it is logically impossible or selfcontradictory for it to be false. Philosophy of Religion 5: Ontological Arguments Page 7 For example, the statement “all bachelors are unmarried” is necessarily true because the opposite “some bachelors are married” could not possibly be true. If something is necessarily false, then it is logically impossible or selfcontradictory for it be true. For example, the statement “my mother is younger than me” is logically impossible. Just by understanding the concepts of the terms “mother” and “younger”, we know that it must always be false, without knowing anything about the world. Malcolm’s Ontological Argument Malcolm starts by considering every possible situation regarding God’s existence: A. God’s existence is necessarily false (logically impossible) B. God’s existence is contingently false (logically possible but happens to be false) C. God’s existence is contingently true (logically possible and just happens to be true) D. God’s existence is necessarily true (logically necessary- had to be true) Then his argument proceeds: 1. God’s existence is either necessarily false, contingently false, contingently true or necessarily true. (One, and only one, of claims ABCD must be true) 2. B and C cannot be true because God has no beginning or end so cannot be contingent. 3. A cannot be true because God’s existence is not logically impossible (self-contradictory) 4. Therefore, D must be true – God necessarily exists Philosophy of Religion 5: Ontological Arguments Page 8 Response to Malcolm The problem lies with premise 3. Many people claim that the very idea of God (a timeless, omnipotent, benevolent being that exists) is logically impossible. We have already seen examples such as the paradox of the stone and the problem of evil that question the existence of a being with these properties. If the existence of God is self-contradictory, then statement A is true, and statement D must be ruled out instead. Plantinga’s Ontological Argument Plantinga uses a similar strategy to Malcolm. But he bases his argument on the idea of possible worlds. A possible world is the way the world could have been. Some possible worlds are the same as this one apart from one small detail. Others are completely different and have flying pigs, or no life at all. But some things cannot be true in any possible world. For instance, there is no possible world where triangles have two sides, 2 +3 = 4 or bachelors are married. Plantinga’s version takes much the same form as earlier ontological arguments, but he changes talk of necessary and contingent existence to a discussion of possible worlds: 1. 2. 3. 4. God is the being with the maximal greatness There is at least one possible world in which God exists It is greater to exist in all worlds than to exist only in some So, because God has maximal greatness, he must exist in all possible worlds 5. Therefore, God exists in the actual world Responses to Plantinga The first response is to deny premise 2. Like in the response to Malcolm, we can deny that the existence of God is possible at all. If the concept of God is incoherent, then there is no possible world in which he could Philosophy of Religion 5: Ontological Arguments Page 9 exist. The existence of a being with God’s properties is as contradictory as the existence of a triangle with 4 sides. The second response is to deny premise 3. Although it might seem obvious that existing is greater than not existing, this is not necessarily the case. It is tempting to think that something that doesn’t exist has zero greatness, which is obviously less than the value of something that does exist. But something that doesn’t exist doesn’t have any value of greatness, not even zero. So, it isn’t greater to exist than not to exist, or to exist in more worlds rather than fewer. Final Thoughts… Is existence a real predicate? Is the idea of God’s non-existence self-contradictory? Is the claim “God exists” analytic or synthetic? Are the modern versions any more convincing than Anselm’s original argument? Philosophy of Religion 5: Ontological Arguments Page 10