The Ontological Argument I: Overview

In an earlier post, I discussed my path from moderate Christianity to atheism.  In that post, I talked about things that influenced me personally, but I did not get into actual arguments in much detail.  I think I'd like to do that, for several reasons including the opportunity to clarify my own thoughts on the matter.

This post will be the first in a series of posts, where I attempt to address as many of the arguments that are offered to support the existence of a god or gods as I can.  I am a physicist, so in many cases my position is that of an educated layperson rather than an expert.  Still, I hope to be able to say something new and accurate.  I also intend a parallel, and probably shorter, series of posts covering arguments against the existence of any gods.  The two sequences will be complementary, since a big reason for my atheism is simply that there are no good arguments to believe.

I'll start with Ontological arguments.


Ontological arguments as a group attempt to prove that God necessarily exists.  The general structure of an ontological argument is as follows:

1. I define God as possessing some set of properties.
2. I argue that it is logically inconsistent for something with the properties of (1) to not exist.
3. Therefore, God exists.

In my experience, many people get this far and then stop, claiming to have proved (for example) Christianity.  I hope I don't have to explain the flaw there; but this does not undermine the potential validity of this reasoning.

In my opinion, ontological arguments for God are the strongest; by which I mean, they are the most difficult to refute.  I don't think they are very convincing; in my not-in-any-way-scientific opinion, most believers are more likely to be persuaded by teleological (design) or cosmological approaches.  These two things are likely both due to the simple fact that ontology is abstract.

I have seen a number of different ontological constructions, and I'll need several posts to address them.  In specific cases, it is often easiest to directly attack point (2) in the list above.  I will end, however, with a more general argument against the entire approach.  This will attempt to put my intuitive position---that you can't use logic to prove something exists---on a more solid foundation.

I had originally intended to wrap this post up by addressing a bad example of an ontological argument, but I don't have one to hand and don't want to make something up.  So this will have to be a relatively content-light post, with heavier stuff to come.