Harming other people is prima facie wrong. Unless we can be very certain that doing so is justified under the circumstances, we ought not to do it. In this paper, I argue that we ought to dismantle harsh retributivist criminal justice systems for this reason; we cannot be sufficiently certain that the harm is justified. Gregg Caruso, Ben Vilhauer and others have previously argued for the same conclusion; however, my own version sidesteps certain controversial premises of theirs. Harsh retributivist criminal (...) justice can only be morally right if the following three propositions are true: Moral responsibility exists, retributivism is right, and we can find out how much punishment offenders deserve for their crimes. Suppose that we initially assign a high credence to each of the three propositions; I assume for the sake of argument that there are good arguments in support of each. Nevertheless, these arguments ultimately depend on intuitions. Since we have philosophical peers whose intuitions differ from ours, we ought to downgrade our credence in each. However, even slightly less credence in each proposition means far less credence in a conjunction of all three. Since the stakes are high and there are morally safer options for a criminal justice system, we ought to dismantle harsh retributivist ones. (shrink)