No one is saying that the object has to be of infinite mass, just enough so that God cannot lift it--in other words, there is no predefined "weight" assumed in the argument. Again, think outside the physically impossible and into the logically possible.
You have brought the "actor" back into the picture, but it is the object in itself that is self-contradictory. It is the unliftable object.
For an object to be logically meaningful, it must have a limited mass and volume. You have confirmed that the "rock" has a limited mass by using the phrase "just enough".
The force required to lift any object is that which is greater than the "weight" of the object. (Weight is measured in units of force. If an object has a weight of X, then the force to lift it is any force greater than X.
It seems that you're missing the fact that there is nothing *self-contradictory* about the such an object. (This is probably best illustrated by the fact that no philosopher of religion [at least that I know of] has argued such.)
No, it is not a fact that I am missing. It is clear to me that an "unliftable" object is logically self-contradictory. This is not a matter of physically possibility, but by the very meaning of something being a physical object. Can you see what I am saying? It's not sufficient to say " ... no philosopher of religion [at least that I know of] has argued such."
Consider what I wrote and try to understand what I'm saying:
- Do you agree that an object, to be logically meaningful, must have at least mass and volume?
- And do you agree that, by definition, the force required to lift that object is any force greater than the weight of the object?
(Mass and weight are technically two different things having different fundamental units, but a weight can be determined for any given mass, and weight is not fixed for any given mass - weight on the moon for a given mass is less then the same mass on Earth.)
P.S. I may be read as being patronizing - that is not my intention. I just think that if careful consideration is given to what makes a object logically meaningful - that it must have mass and volume - then it is a matter of simple definition that it can be "lifted" by any force greater than it's weight. So an unliftable object is self-contradictory.
P.P.S. Brain Bosse - this would be a great topic for the Christian Logic Discussion Forum - don't ya think? We should get a thread going on the subject there too.