 Completeness (connectedness) is commonly assumed in many applications, not least in economics. Bayesian decision theory is a case in point. The Bayesian decision maker is assumed to make her choices in accordance with a complete preference ordering over the available options. However, in many everyday cases, we do not have, and do not need, complete preferences. Consider a person who has to choose between five available objects \(A, B, C, D\), and \(E\). If she knows that she prefers \(A\) to the others, then she does not have to make up her mind about the relative ranking among \(B, C, D\), and \(E\).