Surrogate reasoning

Surrogate reasoning is reasoning whose task is partially taken over by operations on external aids, such as sentences, diagrams, physical models, mathematical models, and computers. Drawing on the basic concepts in situation theory, we present a semi-formal model of surrogate reasoning. We claim that the relative advantages and disadvantages of different forms of surrogate reasoning can be explained with reference to the ways in which the default constraints on surrogates intervene in the processes of reasoning. We define and examine two prominent patterns of such constraint intervention (dubbed “free rides” and “overdetermined alternatives”). We also introduce the notion of “constraint projection” and try to capture the general framework in which different forms of constraint intervention take place in surrogate reasoning.