The Ontological Argument for God's Existence

God's existence is a hugely significant question for a modern person to ask. If He does, then your life should be in obedience to Him, and if not you are the one in control. Another pertinent question to ask is, even if God exists, what is His nature. Another way of phrasing it would be as follows: which God exists? You wouldn't want to dedicate yourself to Islam, only to find out that Hinduism was true. It is of fundamental importance to the human condition that these questions be raised.

In the next month or so, I will be trying to offer reasons why I believe that the God of the theism, that is, an all powerful, all loving, all knowing being, exists, starting with perhaps my favourite piece of evidence, the Ontological Argument.

The first thing to point out is that this is an 'a priori' argument. That means it is based on reason alone, and simply requires the power of thought and logic to determine its success. If it is true, it is 100% certain and nobody can dispute its truth. If it is shown to be false, it is 100% certain that it is false. This means that, unlike the other arguments for God's existence which only suggest at best that God's existence is probable, if this argument succeeds, then the belief that God exists is logically certain.

This type of argument dates back to around 1000 years ago, and was created by the Archbishop of Canterbury St. Anselm. In that time, it has been modified, attacked, defeated, remade and developed. I intend to only offer what I consider the strongest variant of this argument, which was developed by Alvin Plantinga in the 1970s. It is called the Modal Variant because it uses the idea of 'possible worlds'. A possible world is a logically possible state of affairs. So there is a possible world X in which unicorns exist. There is another one Y where Ed Miliband is a tennis player. And there is a possible world Z where I get the girl of my dreams. Now the actual world is also a possible state of affairs, and thus it too is a possible world. But unlike other possible worlds which are just imaginary possibilities about how the world could have been, the actual world truly exists.

Now the argument runs as follows:

1) A maximally great being is one who is all powerful, all knowing, all loving, and has all other great making properties (that is, a property which has a maximum limit, such as knowledge).

2) It is possible that a maximally great being (God) exists.

3) If  it is possible that a maximally great being exists, then it must exist in some possible world.

4) If a maximally great being exists in some possible world, then it exists in every possible world (because it is greater to exist in all logically possible worlds than just one, and as a maximally great being, it must exist to a maximum capacity in possible states of affairs.)

5) If a maximally great being exists in every possible world, then it exists in the actual world.

6) Therefore, if a maximally great being is even possible, it exists in the real world.

7) As a maximally great being is by definition the theistic God, God must exist if his existence is merely possible.

A lot of people think that there is a trick hidden in this argument, but actually it is just an argument based on old fashioned logic. It may be surprising for you to know that the logic of the argument is also sound, most critics do not dispute that. The real question is whether God's existence is possible. On the face of it, there seems no apparent contradiction in the concept of God. So prima facie, this argument is successful.

Thus, the burden of proof is on the sceptic to show that God's existence is not only highly improbable, but impossible. If this cannot be achieved, then by the mere possibility of God's existence he exists. So far, no one has convincingly showed that the concept of God is contradictory, and as there is evidence that the existence of God is probable by other arguments (such as the cause of the universe, the designer of the intrinsically improbable fine tuning, the founder of morality, the cause of religious experiences, miracles and the resurrection of Christ) it follows that this argument succeeds in proving the existence of God.

If you think that the existence of God is even possible, then I encourage you to also arrive at the same conclusion as this argument that you must also believe that God exists. Follow it through, and you shall see that if you accept that the existence of God might be true, no matter how improbable, then logic demands you should also believe that He exists not only in some other possible state of affairs, but the real world too.