I have read about the notion of necessity in a logical sense. For example, 2+2=4 seems to be logically necessary.
But I have also read about the notion of metaphysical necessity. God, for example, is argued to be an example of one kind of metaphysical necessity. Full causal determinism is also often taken to be an example of this. If everything is determined, it becomes necessary.
But if one can imagine alternate states of affairs even if determinism is true or if there is some God who does certain things necessarily, isn’t the mere imagination evidence that it is contingent? For example, one can imagine different laws in the universe. Or one can imagine a different kind of god, or no god at all. There would presumably be no reason as to why a certain law would exist rather than another, even if everything was determined by certain laws.
But since there is no reason, wouldn’t it be a brute contingency rather than a necessity?