Andrew Sepielli

Sometimes it’s not certain which of several mutually exclusive moral views is correct. Like almost everyone, I think that there’s some sense in which what one should do depends on which of these theories is correct, plus the way the world is non-morally. But I also think there’s an important sense in which what one should do depends upon the probabilities of each of these views being correct. Call this second claim “moral uncertaintism”. In this paper, I want to address an argument against moral uncertaintism offered in the pages of this journal by Brian Weatherson, and seconded elsewhere by Brian Hedden, the crucial premises of which are: that acting on moral uncertaintist norms necessarily involves motivation by reasons or rightness as such, and that such motivation is bad. I will argue that and are false, and that at any rate, the quality of an agent’s motivation is not pertinent to the truth or falsity of moral uncertaintism in the way that Weatherson’s and Hedden’s arguments require.

Normative judgments involve two gradable features. First, the judgments themselves can come in degrees; second, the strength of reasons represented in the judgments can come in degrees. Michael Smith has argued that non-cognitivism cannot accommodate both of these gradable dimensions. The degrees of a non-cognitive state can stand in for degrees of judgment, or degrees of reason strength represented in judgment, but not both. I argue that (a) there are brands of noncognitivism that can surmount Smith’s challenge, and (b) any brand of non-cognitivism that has even a chance of solving the Frege–Geach Problem and some related problems involving probabilistic consistency can also thereby solve Smith’s problem. Because only versions of non-cognitivism that can solve the Frege–Geach Problem are otherwise plausible, all otherwise plausible versions of noncognitivism can meet Smith’s challenge

Nobody's going to object to the advice "Do the right thing", but that doesn't mean everyone's always going to follow it. Sometimes this is because of our volitional limitations; we cannot always bring ourselves to make the sacrifices that right action requires. But sometimes this is because of our cognitive limitations; we cannot always be sure of what is right. Sometimes we can't be sure of what's right because we don't know the non-normative facts. But sometimes, even if we were to know all of the non-normative facts, we'd still not be sure about what's right, because we're uncertain about the normative reasons those facts give us. In this dissertation, I attempt to answer the question of what we're to do when we must act under fundamentally normative uncertainty. It's tempting to think that, in such circumstances, we should do what we regard as most probably right. I argue that this view is mistaken, for it is insensitive to how degrees of actions' values compare across different normative hypotheses; if an action is probably right, but, if wrong, is terribly, terribly, wrong, it may be rational not to do that action. A better answer is that we should do the action with the highest expected value. I spend the first part of the dissertation providing arguments for and rebutting arguments against this view of action under normative uncertainty. I spend the next part of the dissertation explaining what degrees of value are, and showing how they can be compared across normative hypotheses. In the remaining parts of the dissertation, I consider two questions related to our primary question -- first, what is one required, or obligated, to do under normative uncertainty; and second, what is it rational for one to do when one is not only normatively uncertain in the way we've been discussing, but also uncertain about what it is rational to do under this sort of normative uncertainty.