In his wonderful paper, "Indicative Conditionals", (which I have recently reread because of a great paper on it by Fabrizio Cariani) Stalnaker presents a theory that allows him to maintain a unified semantics of the ordinary-language conditional, that is, without having one semantics (broadly construed) for so-called indicative conditionals like 'if it's raining, the streets are wet' and another for so-called subjunctive conditionals (aka 'counterfactuals') like 'if it were raining, the streets would be wet'. I want to challenge his maneuver here, and I want to suggest that any maneuver won't work, either. In an important sense, supposition is too powerful an attitude; there are too few restrictions on what we may suppose, and thus on what conditionals we may assert.
In my last post, I introduced a principle, Clarity, which is that we ought not to have unclear beliefs. I then tried to define when a belief is unclear. Roughly, what I said there was that a person S's belief is unclear if S doesn't know what it rationalizes or it is rationalized by. In this post, I'm going to make that definition a little clearer, and then get a little further in actually justifying Clarity. (This post is readable without reading the first one.) I'll argue that unclear beliefs generate avoidable epistemic problems; since they are avoidable, we ought to avoid them; so we ought not to have unclear beliefs.
I want to explore a principle I will call Clarity. My point will not be to defend it, exactly, but rather to clarify it and put it to work in an argument that seems to me very interesting. Here's a rough formulation:
Clarity. All agents are rationally required not to believe any proposition that is unclear to them.
This formulation leads a lot open (and thus might be autological right now), but I want to focus on what 'unclear' might mean. To do that, we need to see why a principle like Clarity might be intuitive in the first place; that will provide some discipline on what 'unclear' can mean.