Excursus on Natural Theology (Part 24)

We’ve been talking about the ontological argument, and I hope today to bring our discussion of that argument to a close. The last time we saw that the crucial premise in the argument is the first one. If you grant that premise, then the rest of the argument just follows automatically. If it’s possible that a maximally great being like God exists, then it follows necessarily that God does exist. So the question is what warrant there is for that first premise, and I argued that we can see that the concept of a maximally great being is a coherent concept. It’s not like a square circle or a married bachelor. This is a coherent notion that could possibly be instantiated. Therefore we have a prima facie warrant for thinking that that first premise is true, that it’s possible that a maximally great being exists.

So far we’ve been looking at a priori considerations in defense of the first premise of the ontological argument.  But Plantinga suggests is that there could also be some a posteriori reasons for thinking that premise (1) is true. That would put a very different face on the ontological argument. What might these be?

The Value Argument

Joshua Rasmussen has offered what he calls “the Value Argument” in support of the key premiss of the ontological argument:[1]

1. Some degree of value can be instantiated.
2. If some degree of value can be instantiated, then each degree of value can be instantiated.
3. Therefore each degree of value can be instantiated.
4. Maximal greatness is a degree of value.
5. Therefore, maximal greatness can be instantiated.

This disarmingly simple argument provides some non-question-begging, a posteriori support for the first premise of the ontological argument. For our moral experience reveals that some degree of value is, in fact, instantiated, whence it follows that (1). As for (2), Rasmussen notes that a mere difference in degree of a value does not affect the possibility or impossibility of a value of that degree. Rather there is plausibly a modal continuity for degrees of value. In support of (4), he claims that maximal greatness is a determinant of value; namely, it is a maximum value. Every determinant of value is a degree of value. So maximal greatness, as a degree of value, can be instantiated.

I find the value argument very persuasive, and it increases my confidence that it is possible that a maximally great being exists.

Moreover, it seems to me that the other arguments of natural theology for the existence of God can go some distance toward justifying belief that it is possible that such a being exists. For example, Leibniz’s argument from contingency, certain versions of the moral argument for God’s existence, and the argument from the applicability of mathematics could lead us to think that it is plausible that maximal greatness is possibly exemplified.

For example, remember the Leibnizian argument from contingency that we’ve already talked about. It goes like this:

1. Everything that exists has an explanation of its existence. This explanation might either be a necessity of its own nature (in which case it is a metaphysically necessary being) or in some external cause.

2. If the universe has an explanation of its existence, that explanation is God.

3. The universe is an existing thing.

From these three premises it follows logically that:

4. Therefore the explanation of the existence of the universe is God (who is a being that exists by a necessity of his own nature).

Any being that exists by a necessity of its own nature is going to be a metaphysically necessary being. So Leibniz’s argument gives us good grounds for thinking that there is a metaphysically necessary being upon which everything else depends for its existence. So there are no limits to the power of this being. There are no non-logical limits to the power of this metaphysically necessary being because everything that exists depends upon it for its existence.

Or consider the moral argument for God’s existence. Again, we’ve already talked about the moral argument. It could be summarized like this:

1.   If God does not exist, then objective moral values and duties do not exist.

If there is no God then there is no absolute standard of right and wrong, good and evil. Everything becomes relative.

2.   Objective moral values and duties do exist.

Certain things are really right or really wrong. Certain things are really good or really evil.

3. Therefore God exists.

Now, if moral values and duties depend in this way upon the existence of God, then, since certain moral principles are necessarily true, it follows that the God who grounds them must be a metaphysically necessary being. That is, a being that exists in all possible worlds. For example, one naturalist philosopher of science, Michael Ruse, has written, “The man who says that it is morally acceptable to rape little children is just as mistaken as the man who says 2+2=5.”[2] Think of that statement. Here Ruse equates the truth of these moral principles with the elementary truths of arithmetic like 2+2=4. These are necessary truths. These are logical truths. Therefore these moral principles, to be grounded in God, require that God be a metaphysically necessary being who exemplifies these moral values necessarily. Therefore the moral argument also leads to the existence of a metaphysically necessary being who is not merely perfectly good but who is the actual standard of goodness, who is the paradigm of goodness from which all moral value derives.

Thirdly, in addition to this, we have the argument from the applicability of mathematics:

1.   If God does not exist, the applicability of mathematics is just ‘a happy coincidence.’

2.   The applicability of mathematics it’s not just ‘a happy coincidence.’

3.   Therefore, God exists.

We saw that the applicability of mathematics is best explained by saying that God constructed the physical world on the basis of the mathematical model that he had in mind. If mathematical truths and objects are thus grounded in the mind of God, then God must be a metaphysically necessary being. God is plausibly an infinite, metaphysically necessary person who grounds these mathematical objects. Thus you are brought to the conclusion of the existence of an omniscient, metaphysically necessary mind as the foundation of the applicability of mathematics..

Look at what these three arguments give us. Each one of them gives us a metaphysically necessary being – a being that exists in every possible world. The Leibnizian argument, the moral argument, the mathematical argument all yield a metaphysically necessary being. The Leibnizian argument gives you a being which is the source of all reality outside itself and therefore is plausibly all-powerful. The moral argument gives you a being which is morally perfect. The mathematical argument gives you an omniscient mind which grounds these mathematical truths. In other words, you’ve got here the elements that make up maximal greatness, don’t you? You’ve got metaphysical necessity, omnipotence, moral perfection, and omniscience.

So these other arguments of natural theology can provide support for the idea that it is possible that a maximally great being exists. I think here considerations of simplicity also come into play. For example, it is simpler – isn’t it? - to postulate one metaphysically necessary, infinite, omniscient, morally perfect being than to think that there are three separate beings that have these properties, that there are three metaphysically necessary beings – one of which is omniscient, one is morally perfect, and one is omnipotent. It is simpler to say that all of these arguments are leading to the one metaphysically necessary being who is omnipotent, omniscient, and morally perfect.

Moreover, as Richard Swinburne has pointed out, it seems plausible that it is simpler or less ad hoc (less contrived) to say that a property that comes in degrees has either zero or infinity as its value rather than some arbitrarily selected finite value in between. It would be simpler to just say it is infinite or it is zero rather than having an inexplicable finite value somewhere on the measurement scale. So it would be more plausible to think that maximal greatness is possibly instantiated than quasi-maximal greatness – a being which has infinite power, intelligence, and moral perfection.

So on the basis of these sorts of a posteriori considerations, I think that we could well consider ourselves to be warranted in believing that it is possible that a maximally great being exists.

Now the question which arises at this point is: Doesn’t the ontological argument now become question begging? What does it mean for an argument to be question begging? What it means is that your only reason for accepting a premise in the argument is that you already believe in the conclusion. You accept the premise because you already believe the conclusion is true. So you are begging the question or you are arguing in a circle. Let me give an example.

Consider this as argument for God’s existence.

1. Either God exists or the moon is made of green cheese.

2. The moon is not made of green cheese.

3. Therefore God exists.

That is a sound argument for God’s existence. Both of its premises are true. Since God does exist, it is true that either God exists or the moon is made of green cheese. In order for that disjunction to be true, one of the disjuncts needs to be true. Since God does exist, it is true that either God exists or the moon is made of green cheese. The second premise is true – the moon is not made of green cheese. Therefore God exists. So this is a logically valid argument with true premises which implies the existence of God. Yet no one would think this is a successful piece of natural theology. Why not? Because the only reason you would have for thinking that the first premise is true is because you already believe the argument’s conclusion that God exists. So you are reasoning in a circle. You are begging the question.

The question now is: if the reason that you think it is possible that a maximally great being exists is because you believe that a maximally great being does exist, then aren’t you similarly begging the question? If on the basis of the Leibnizian, moral, and mathematical arguments for God’s existence, you come to believe that a maximally great being exists, then of course it’s possible that he exists! You’ve already proven that he does! So doesn’t the ontological argument then become question-begging or redundant?

I think that this misgiving may result from thinking of the project of natural theology in too linear a fashion. We should not think of the arguments of natural theology as being like links in a chain, where the chain is only as strong as the weakest link. If the weak link is broken, then the whole chain is broken and becomes unable to bear the weight that you would want. We shouldn't think of the arguments of natural theology in that linear fashion, as like a chain of links which is only as strong as the weakest link. Rather the arguments of natural theology are more aptly compared to a coat of chain mail like the coat a knight used to wear, where the links all reinforce one another, so that the coat of mail is not as weak as the weakest link. The ontological argument can play, I think, an important role in a cumulative case for the existence of God in which a whole host of independent factors lead us to the overall conclusion Therefore God exists.”

It does seem to me that the ontological argument has a role to play as one of the links in the coat of mail – one of the arguments in a cumulative case for God’s existence. So the arguments taken together show that God, a maximally great being, does in fact exist.

With the ontological argument we draw to a close our discussion of the arguments of natural theology. This section of the course is vital in establishing the plausibility of a Christian worldview in a secular society. We’ve looked at the proper basicality of belief in God’s existence. We’ve looked at the contingency argument, the cosmological argument, the argument from the applicability of mathematics, the fine-tuning argument, the moral argument, and the ontological argument for God’s existence. These give us, not  the existence of a vaguely characterized being that could be the Flying Spaghetti Monster. Rather these give us a being replete with specific attributes like moral perfection, omnipotence, omniscience, metaphysical necessity, and so forth.

The arguments of natural theology for God’s existence are in a sense only one side of the coin because we also need to consider what are the arguments on the other side against the existence of God. Maybe there are such powerful arguments for atheism that they simply outweigh these arguments for God’s existence and tip the scale in the other direction. What we want to take up beginning next week will be arguments for atheism, and especially the problem of suffering and evil in the world. Isn’t the existence of an omnipotent, all-loving God, incompatible or improbable given the truly horrendous and innocent suffering in the world? How are we going to deal with that problem? That will be the question that we will take up next time.