 Mentalists, in contrast, insist that choices and preferences are entities of quite different categories: Preferences are states of mind whereas choices are actions. Consequently, they reject the strong behaviourist program (Hausman 2012). An important mentalist argument against behaviourist interpretations concerns the role of beliefs in decision making. According to this argument, some choices are not based on stable preferences over actions, but are constructed from more basic cognitive and evaluative elements. A simple choice – like choosing between two pieces of candy – might be based on a preference for a world in which one eats candy \(X\) over a world in which one eats candy \(Y\). But more complex choices – e.g. choosing one’s higher education – depend on what one believes these choices to bring about, and how one evaluates these consequences. In those cases, a more complex framework specifies beliefs about the probability or plausibility of possible states of the world, preferences over the consequences of choices in those worlds, and an aggregation mechanism of these preferences under those beliefs. The need for such a cognitive structure to account for preferences has been proposed as an argument against the ontological reduction of preferences to choices (Hausman (2012).