Beyond Ought-Implies-Can: Impersonal Obligatoriness Implies Historical Contingency

Abstract

I argue first that some propositions are obligatory without being obligatory for anyone (i.e., they are impersonally obligatory): if each of us has promised to vote and thus has an obligation to vote, then it is obligatory (i.e., morally required) that we all vote, but it is not obligatory for anyone that we all vote (because, for example, what is obligatory for you is that you vote, not that we all vote). I argue next that “ought-implies-can” fails for impersonal obligatoriness: if each of us has promised to (and can) finish first in a given race, and thus it is impersonally obligatory that we all finish first (i.e., that we all finish at the same time), it does not follow that anyone (or we) can make it the case that we all finish first (we may be unable to coordinate). I defend instead the following principle: if a proposition is (impersonally) obligatory—or forbidden—at time t, then it is historically contingent at t (i.e., both the proposition and its negation are logically compatible with the history of the world up to and including t).