The Muffti was intrigued by a question of TM’s the other day asking about whether or not we could prove or disprove God’s existence. While many (i.e. such luminaries as Kierkegaard and our own Laya) think it is an empty endeavour since faith is precisely that state where you believe without proof or evidence, others have been fairly convinced that irrationality is a fault not a virtue and have pursued proof either way. The Muffti thought there might be some interest in this so here are a few highlights from the last 2000 years of philosophical/theological thought on the matter. This will be a rather breezy guide, but much serious work has been done on all of these arguments.
A fellow named Anselm, attempting to refute the fool who denies God in his heart, came up with the following a priori proof:
1. To be God is to be that being such that no greater being could be conceived. (this is intended as a definition).
2. Something which exists is greater than something which does not exist. (Premise)
3. Therefore, God must exist. If he didn’t then there would be a greater being you could conceive of (namely, an existing one). But God just is the greatest conceivable being (see premise 1). So you get a contradiction by denying God’s existence.
A brief note: premise 2 is supposed to be obvious. Existing is intended to mean ‘existing in the world’ as opposed to existing merely in the imagination. Needless to say, this argument has not won a whole lot of favour of the years (though some luminaries such as Descartes seem to have bought it). What has been striking is the volume of diagnoses of how badly this argument does. Kant thought that ‘existence’ wasn’t a predicate, which premise (2) seems to rely on. Frege thought that ‘existence’ was a property of properties rather than of individuals, which would falsify (2) as well. The Muffti can think of many other reasons why this argument fails but will leave it as an exercise for the reader.
If you thought the last one was bad, here’s an even worse version of it. Preliminarily: ‘necessary’ in this argument is analyzed as something which could not fail to exist. God has usually been thought to be a necessary existent: it is impossible for him to just fail to exist. With that in mind:
1. It is possible that God exists.
2. God is a necessary being.
3. Necessary beings can’t fail to exist.
4. Therefore, God must exist.
The idea comes from an axiom of modal logic that says that if it is possible for something to exist, then it is necessarily possible that it exists. The argument has been criticized on quite a few grounds as well, most compellingly for its confusion of what is known as epistemic possibility (the notion used in premise (1)) and metaphysical possibility (what is used in premises (2) and (3).) Also notable is that no atheist accepts premise (1), so at best this argument should make agnostic people worried.
This one really sucks and it comes to us, I believe, from Aristotle.
1. Every thing has a cause.
2. There can’t be an infinite chain of causes.
3. Therefore, there must be a first uncaused causer.
4. God is that uncaused causer.
Yup, this is a real winner let me tell you. For starters, note that the sub-conclusion in (3) contradicts premise (1). More notably, Russell persuasively argued that there is no obvious reason to accept (2) and, worse, there seems to be a confusion between the cause of a series of causes and the cause of every member of the series. The Muffti is embarrassed for those who have bought this argument.
This is easily the most promising of the bunch. In essence, it relies on some controversial bits of probability theory. The idea is the following. Modern physics tells us that the basic ‘settings’ or ‘parameters’ of the universe can be set in any number of ways, very few of which support life. However, we find life in the universe. If the process were random, we would expect not to find life since it is so damned unlikely. Givcn that we find life, then, we should suspect that there was a helping hand.
The idea is pretty cute. There are problems to be sorted out. One is the so-called anthropic principle. The principle says, roughly, that if you get evidence for something that you can’t possibly get evidence against, you can’t take that evidence to support anything. Now, WE could not have gotten evidence that we don’t exist, since getting evidence presupposes existence. Thus, we could not have gotten support for the proposition that the world was set in a way that didn’t support life. The Anthropic Principle says that we shouldn’t take the evidence that we exist, then, to support anything.
This would be a nice refutation if the anthropic principle didn’t look very, very suspicious, especially if not qualified in its application. To take a case, imagine that you are given an injection and told that it was either poison that would kill you instantly or a harmless placebo. If you live, surely you get some evidence that you took the placebo, even if you couldn’t have gotten evidence that it was poison.
A more convincing problem with the argument is that it relies on an indifference principle (otherwise we can’t say that it is improbable that the setting would be set as they are). Namely, if there are many possibilities, they are all equi-probable. While that sounds great, the principle is known to lead to contradiction in fairly mundane cases. So I guess I don’t buy the argument at all.
I’ll end with an argument against the existence of God.
1. God is omnipotent, omnibenevolent and omniscient.
2. Therefore, God wants to prevent evil, knows how and is capable.
3. Evil exists.
The 3 premises are supposed to form an inconsistent triad. The challenge, then, is to explain how they can be reconciled since they all seem true. I should note, in this connection, Kenny told me once that he sees no Jewish commitment to God’s omnibenevolence. I thought that was interesting, though a little scary…