These arise when on the face of it you ought to do each of two incompatible actions. That is, each seems obligatory but you can at best do one of them. There is dispute over whether it is right to say that you ought to do one, ought to do each, or ought to do neither. Saying you ought to do both transgresses against the principle that ought implies can. One option is that you ought to do neither, following the analogy that if two runners are first equal, then neither is an outright winner. But it has been argued against this, by Williams, that there is properly a psychologic-al ‘remainder’ of guilt or the need to make reparation, suggesting that the neglected action was obligatory after all.