This is a good point but if those are your stipulations then it is questionable how useful any discussion of the matter about rock lifting is (not that it wasn’t questionable before).
Your argument, as I understand it, is the following. God is a being with at least one special property: it can lift a rock no matter what. The rock that we are introducing has the property that it can’t be lifted. And when we ask whether God can lift it we are talking nonsense because we *made it to be * that God can lift anything, so either God can’t lift everything (which we don’t want to admit) or the stipulation that the rock can’t be lifted is meaningless, because there exists at least one situation in which it ‘can’ be lifted, namely when God is the lifter.
Tell me if this is an inaccurate picture of your argument.
My problem with it is that it solves the problem merely by definition, and thereby does not even address the original problem. The problem, as I see it, is a bit more subtle. It is not just that an unliftable rock is to be admitted into the picture; rather the way in which it is admitted into the picture is what is problematic (I mean, it’s already obvious that independent of who makes the rock, God can lift it). With the paradox, we are asking if God’s omnipotence in one respect is limited by it in another. And that seems to be a legitimate question that isn’t addressed by your solution.
I’m not sure if it’s an accurate picture of my argument, since I think you may have phrased it a little more complicatedly than I would like. Let me try putting it this way.
We are asking if a coherent understanding of “omnipotence” is possible. Now you are concerned that I solve the problem only “by definition,” and this is completely true. But that is also the issue. Before this objection became outdated (few modern atheist philosophers take it seriously anymore), it was an attempt to raise a by problem “by definition,” that is, to say that no coherent understanding of omnipotence is even possible. What the theist wants to do then, is show that there is a coherent understanding of omnipotence possible after all.
Now the atheist who raises this question has typically made the mistake of defining God’s omnipotence in a way that causes him to be attacking something of a straw man. He sees God’s omnipotence as a matter of raw power, but theists have realized that this is an intellectually poor understanding of omnipotence.
Instead of seeing it in terms of raw power, God’s omnipotence should be seen in terms of actualizing potential or possible states of affairs. God’s omnupotence, then should be seen as his ability to actualize any logically possible state of affairs (there are a couple extra stipulations as well, but let’s go with this for now).
for instance, can God make a square circle? To the non-theist who insists on conceiving of God’s omnipotence in terms of raw power, this is a puzzle. But with our more sophisticated understanding of omnipotence being the ability to actualize states of affairs, we understand that the words “square circle” do not describe a logically possible state of affairs. They are nonsense. So God cannot make a square circle, but this is no limit to his omnipotence.
So the question is: do the words “a stone so heavy that God (or a “Greatest Conceivable Being”) cannot lift it” describe a potential state of affairs? The answer seems to be clearly no. Because if such a being could not lift such a stone, then he would not be a greatest conceivable being, because we could conceive of a greater being, one that could lift the stone, and that being would be God. Since the words “a stone so heavy God cannot lift it” do not describe an actual state of affairs, God cannot create such a thing, because there is no such thing. It is only nonsense and empty words.
So God’s omnipotence is not hindered by his inability to do the logically impossible, namely create a rock so big he cannot lift. His lifting power and his creative power and not at all contradictory then, as long as you see this, and that omnipotence is not a matter of raw power in one respect and raw power in another, but about ability to actualize possible states of affairs.