We believe, disbelieve and suspend judgment based on reasons all the time. I think these reasons are best thought of as mental states of the subject. Other people think that they’re best thought of as propositions.
Suppose Peggy believes that God exists (Q) only if there is no unnecessary suffering in the world (~P). And she suspends judgment (i.e. withholds) on whether there is no unnecessary suffering in the world. She consequently withholds on whether God exists. We can represent her transition in thought like so.
B(Q → ~P) [ed. note: added a missing tilde here]
This seems like a perfectly sensible bit of reasoning.
Peggy’s withholding is reason-based. What are the reasons that form its basis? I say: her belief that (Q → ~P), along with her withholding on ~P. I cite two of her mental states. My view doesn’t endanger the observation that Peggy’s reasoning is perfectly sensible.
Now suppose that you wanted reasons to be propositions instead of mental states. On the most straightforward version of this view, you’d simply identify Peggy’s reasons with the propositional contents of those mental states which I say form the basis of Peggy’s belief. But it seems to me that this view gives a very odd result in Peggy’s case, to wit, it entails that Peggys withholding on Q is based on: [(Q → ~P) & ~P]. But reasoning that way certainly isn’t sensible!
How could someone who thinks that reasons are propositions effectively handle this example?