A theorem in modal logic says that "if it is possible that G is necessary, then G is necessary." If G = God, does this mean that God is necessary? Does "possibility of necessity of God" actually mean anything in the real world?
by 
hijklmno
ANSWERS: 5
-
I think the bigger question is much more personal in understanding and that is: Is God necessary?
-
Doesn't G have to be a proposition or a statement? Like G = "God exists."
-
Not really. Get a job and be rich.
-
According to this article http://plato.stanford.edu/entries/logic-modal/ one way to interpret "it is necessary that G" is to say that "G is true in all possible worlds." So if there is a possible world where G is not true, then it is not necessary that G. So "Either 2+2=4 or it is not" is necessary, but "George W. Bush is president of the U.S." is not necessary. "It is possible that" is defined as "It is not necessary that it is not the case that." In the real world, how do you determine whether something is necessary, or true in all possible worlds? That's too deep for me to answer.
-
If G means 'God exists', and we define god as: that whose possible existence (<>G) entails its necessary existence ([]G), then we can prove that G is necessarily true. premise 1. <>G -> []G, by definition. premise 2. <>G therefore 3. []G, by modus ponens.
RELATED QUESTIONS
Copyright 2023, Wired Ivy, LLC