Bart Streumer

Many philosophers claim that it cannot be the case that a person ought to perform an action if this person cannot perform this action. However, most of these philosophers do not give arguments for the truth of this claim. In this paper, I argue that it is plausible to interpret this claim in such a way that it is entailed by the claim that there cannot be a reason for a person to perform an action if it is impossible that this person will perform this action. I then give three arguments for the truth of the latter claim, which are also arguments for the truth of the former claim as I interpret it.

Jonas Olson writes that "a plausible moral error theory must be an error theory about all irreducible normativity". I agree. But unlike Olson, I think we cannot believe this error theory. I first argue that Olson should say that reasons for belief are irreducibly normative. I then argue that if reasons for belief are irreducibly normative, we cannot believe an error theory about all irreducible normativity. I then explain why I think Olson's objections to this argument fail. I end by showing that Olson cannot defend his view as a partly revisionary alternative to an error theory about all irreducible normativity.