ABSTRACT
Chapter 5 trades on the distinction between theory choice and theory diagnosis in science. Theory choice is the selection of one cognitive option (a theory or a hypothesis, for instance) rather than another; theory diagnosis determines where to place cognitive blame when a theory implies a falsehood. The chapter opens with a critical review of four approaches to theory choice. One of these approaches is to apply decision theory by treating theory choice as a decision under risk. This approach is overly demanding, for a great deal of numeric information, supposedly provided by point-valued probability and utility functions, is required to make it work. To ameliorate this difficulty, the chapter appeals to the comparative decision theory presented in Chapter 4. The chapter illustrates how comparative decision theory affords rational reconstructions of decisions made by exemplary scientists in two cases of theory choice: Buffon’s law and the luminiferous ether. It also offers rational reconstructions of two cases of theory diagnosis: Mendeleev’s anomalies and the Pioneer anomaly.
