 This way of relating preferred indifferents to the end, i.e., to happiness, was challenged in antiquity as incoherent. Plutarch, for instance, argues that it is contrary to common understanding to say that the end is different from the reference point of all action. If the reference point of all action – what one does everything to achieve – is to have preferred indifferents such as health, then the end is to have preferred indifferents. However, if the end is not to have preferred indifferents (but, say, always to act prudently), then the reference point of all action cannot be the preferred indifferents (On Common Conceptions 1070F–1071E). The Stoics are presented with a dilemma: either preferred indifferents are integral to the end or they are not the object of choice.