This paper presents a puzzle about moral responsibility. The problem is based upon the indeterminacy of relevant reference classes as applied to action. After discussing and rejecting a very tempting response I propose moral contextualism instead, that is, the idea that the truth value of judgments of the form "S is morally responsible for x" depends on and varies with the context of the attributor who makes that judgment. Even if this reply should not do all the expected work it is a first step.
"A Puzzle About Responsibility A Problem And Its Contextualist Solution".