Assistant Professor of Philosophy Lara Buchak’s book project, “Risk and Rationality,” argues for a new theory for understanding risk and the decision-making process. Decision theories are theories of practical rationality: they formalize constraints of consistency between rational agents’ ends and the means they take to arrive at these ends. The prevailing view is that subjective expected utility theory, which dictates that agents prefer gambles with the highest expected utility, is the correct theory of practical rationality. Professor Buchak argues that this theory overly restricts the attitudes that agents can take towards risk. She calls for an alternative, more permissive, decision theory—one that permits rational agents to care about “global” properties of actions, such as the value of the worst possible outcome that might result, when deciding which means to take to their ends. Professor Buchak thus asserts that the sense in which most actual people are risk averse, long considered a mark of irrationality, is in fact rational.