 In most ordinary choice situations, the objects of choice, over which we must have or form preferences, are not like this. Rather, decision-makers must consult their own probabilistic beliefs about whether one outcome or another will result from a specified option. Decisions in such circumstances are often described as “choices under uncertainty” (Knight 1921). For example, consider the predicament of a mountaineer deciding whether or not to attempt a dangerous summit ascent, where the key factor for her is the weather. If she is lucky, she may have access to comprehensive weather statistics for the region. Nevertheless, the weather statistics differ from the lottery set-up in that they do not determine the probabilities of the possible outcomes of attempting versus not attempting the summit on a particular day. Not least, the mountaineer must consider how confident she is in the data-collection procedure, whether the statistics are applicable to the day in question, and so on, when assessing her options in light of the weather.