Shifting Scope: A Model of Instrumental Rationality

ABSTRACT The paper develops a new model of instrumental rationality: There is a general concept of instrumental rationality that has two types of instances that differ with regard to coherence and scope. The ‘primary aspect’ applies in effect only to cases where an agent has reason to do what she intends to do and corresponds to a narrow‐scope requirement. The ‘secondary aspect’ applies also to cases where an agent does not have reason to do what she intends to do and corresponds to a wide‐scope requirement. The model has a number of significant features: (i) It enables accounts of the connections between instrumental rationality and coherence. (ii) It enables accounts of the connections between instrumental rationality and reasons. (iii) It makes it possible to explain different cases of instrumental rationality and irrationality and how they are related to one another. The model can be employed by both structure‐based and reason‐based views on instrumental rationality that consequently may make use of its explanatory resources.