What is the Ontological Argument?

Listen as special guest Dr. William Lane Craig explains the Ontological Argument.

Grab a copy of Dr. Craig's new book "On Guard" to learn more about this and other arguments on how to defend your faith with reason and precision.

Transcript

Bobby Conway: Dr. Craig, what is the ontological argument?

Dr. Craig: The ontological argument is an argument intended to show that if God’s existence is even possible, then it follows that God exists. So, if this argument is sound, it puts the atheist in a very awkward position. The atheist must deny not merely that God exists, he must maintain that it is impossible that God exists. And that is certainly a radical claim that would require great justification.

The ontological argument goes something like this: God is, by definition, the greatest conceivable being. Now, what would the greatest conceivable being be like? Well, he would be omnipotent, he would be omniscient, he would be all-good, and he would be necessary in his existence—he would exist in all possible worlds.

Now, if such a being is possible, that means that a being like that exists in some possible world. But you see, if a being of that nature exists in even one possible world, then it exists in all of them, because that’s part of what it means to be the greatest conceivable being. But if it exists in all of them, then it exists in the actual world. Therefore, God exists.

So, the argument is basically: if you think that God’s existence is possible, then it follows that God exists. So, do you think it’s possible that God exists? Well, I do. It seems to me that the concept of a being who is omnipotent, omniscient, morally perfect, and necessarily existent is a coherent concept that’s possibly instantiated, and therefore, I believe that God does exist.