By 'God' I mean a person who is all-powerful (omnipotent), all-knowing (omniscient) and all-good (omnibenevolent). I take it that possession of those properties is sufficient to make one God. I do not want to debate this, it is just to tell you what I mean by 'God'.

I, in common with Jesus and Descartes and others, would understand being 'all-powerful' essentially to involve being able to do anything. In fact, I think it's the other way around - God is described as 'all-powerful' as an attempt to express the idea that God can do anything.

But interestingly most contemporary philosophers of religion understand omnipotence differently. They interpret omnipotence to involve being able to do all that it is logically possible for one to do (actually, they normally qualify it a bit further to avoid certain problems).

This strikes me as most odd, indeed rather absurd - it really isn't an undestanding of 'omnipotence' at all, but an attempt to redefine the term so that it no longer refers to being all-powerful. For surely it is self-evident that a being who is restricted by what logic says is possible is a being who has less power than one who is not? That seems undeniable.

For a being who is restricted by logic cannot make a square circle, whereas one who is not can. So the one who can has more power than the one who can't, right?

Consider too that a being who is restricted by logic cannot reason fallaciously. Yet that's something all of us can do (and do do, regularly). A being restricted by logic will be compelled, in his thinking, to draw a particular conclusion from a certain set of premises, whereas I am free to draw any old conclusion I want. Well, even though that being reasons very well, I now have powers that this being does not have. Which is absurd if that being is also being touted as all powerful.

One might object that the power to reason fallaciously is not a power worth having. Perhaps, but that's beside the point: we're not talking about the 'value' of various powers, just the quantity of them one possesses. So someone who makes this objection is trying subtly (or not so subtly) to change the topic.

Why, then, do so many contemporary theists maintain and promote this patently confused understanding of omnipotence? (which is really not an understanding of omnipotence at all, but an attempt at replacing it with something else).

I think there are two reasons, both of them bad. The first is that many seem to think that certain proofs of God's existence - in particular, ontological and cosmological arguments - imply the existence of a necessary existent. This is a bad reason, because a) even if they did, that would just mean they refute God rather than prove him - re-labelling what you've proved 'God' will not help; and b) they don't.

The second bad reason is that it is thought that there is something absurd in the idea of a being who is able to make married unmarried men and square circles. Or perhaps, it is thought that these things, being logically impossible, are not abilities at all.

This is a bad reason, however, because it is flagrantly question begging. That is, it just supposes that logic - and not God - determines what is truly possible. Yet the whole point is that if God is all powerful then, by virtue of being all powerful, it would be God - not logic - that determines what's truly possible.

So anyway, I think most contemporary theists are seriously - seriously - confused and that an omnipotent being can do anything at all, and that there are no problems with this idea. Indeed, it just 'is' the idea of a truly omnipotent being and anyone who tries to redefine omnipotence in ways that place restrictions on God is simply replacing God with someone who is unable to do a range of things.