I keep bumping into possible worlds semantics, for subjunctive conditionals, in the course of trying to find out about (the metaphysics of) various other things, and so I need to work out what they are doing, what they bring to such analyses. I’ve not studied them properly, so what follows is just my thoughts on what I take to be a typical example (so if it’s atypical, or my thoughts about it are poor, please let me know). Anne bumps into a table, which she’d previously asked Bob to move, and says, “If you’d moved that table I wouldn’t have bumped into it.”
......Clearly Anne is, with her utterance, doing something like blaming her accident on Bob, but what was actually said, literally? Anne said that, had Bob moved the table, she would not have bumped into it, so my first thought is that if the table had been moved, Anne might actually have been more likely to bump into it, especially if the table had been moved by only a small amount. (Indeed, it is quite consistent with the story thus far that Bob did disturb it slightly.) Would that alone be enough to make Anne’s claim literally false? Maybe, but then maybe bumps in general, and the intended ones in particular, are not defined well enough for Anne’s claim to have a definite truth-value.
......Still, I’ll presume that we can include, in the literal meaning, all sorts of information that was implicit in the context of the utterance (otherwise much of what we said might have no literal meaning at all). The literal meaning might still be some vague range of more precise meanings; but what are they? E.g. what if the world was deterministic, so that the actual table could not actually have been moved? Are we then considering similar tables, in some hypothetical Universe? But Anne was explicitly talking about “that table,” not some similar tables (and about Bob, not someone similar). Is it that her subjunctive talk changes those references?
......But why does it not instead mean that we are not assuming that the world is so deterministic? In the conversation there was a presumption of free will (of responsibility for moving the table) and reference to the actual world (via “you” and “that table”). Maybe the world isn’t deterministic (and if it is then maybe Anne’s utterance did not literally have its intended meaning), so why not build some presumption of indeterminism (whose kind might in general depend upon the context) into our interpretation of that utterance (rather than changing its subjects)?