The principle of self-determination plays a crucial role in contemporary clinical ethics. Somewhat simplified, it states that it is ultimately the patient who should decide whether or not to accept suggested treatment or care. Although the principle is much discussed in the academic literature, one important aspect has been neglected, namely the fact that real-world decision making is temporally extended, in the sense that it generally takes some time from the point at which the physician determines that there is a (...) decision to be made and that the patient is capable of making it, to the point at which the patient is actually asked for his or her view. This article asks under what circumstances, if any, temporising—waiting to pose a certain treatment question to a patient judged to have decision-making capacity—is compatible with the principle of self-determination. (shrink)