TWO PARALLEL RIDDLES

Very many of us are convinced that on numerous occasions in our lives we perform actions that are morally right, or wrong, or obligatory. But the seemingly innocuous view that our actions have such moral statuses may not be as secure as we initially believe. I want to generate a riddle about this view that, in many respects, bears striking resemblance to a much more widely known riddle. It will be helpful to start by saying something about this other riddle in order better to appreciate the new riddle.

The venerable old riddle is the riddle about freedom and responsibility. Though fascinating and deeply puzzling, its essentials are easy to grasp. Almost all of us believe that people have been and will be morally responsible for at least some of their behavior. But suppose causal determinism – roughly, the view that all the facts of the past, in conjunction with all the laws of nature, entail one unique future – is true. Then it seems that, at each instant, we would lack genuinely open alternatives; contrary to popular belief, there would be no time at which we could do other than what we in fact did at that time. Causal determinism threatens our very natural picture of the future as a garden of forking paths. Perhaps a more apt figurative representation of what our lives, including our futures, would be like if causal determinism is true is captured by the image of trains chugging along the predestined grooves of a nonbranching trunk line (see Feinberg 1980: 36–7).