Realism and Instrumentalism in Philosophical Explanation

There is a salient contrast in how theoretical representations are regarded. Some are regarded as revealing the nature of what they represent, as in familiar cases of theoretical identification in physical chemistry where water is represented as hydrogen hydroxide and gold is represented as the element with atomic number 79. Other theoretical representations are regarded as serving other explanatory aims without being taken individually to reveal the nature of what they represent, as in the representation of gold as a standard for pre-20th century monetary systems in economics or the representation of the meaning of an English sentence as a function from possible worlds to truth values in truth-conditional semantics. Call the first attitude towards a theoretical representation realist and the second attitude instrumentalist. Philosophical explanation purports to reveal the nature of whatever falls within its purview, so it would appear that a realist attitude towards its representations is a natural default. I offer reasons for skepticism about such default realism that emerge from attending to several case studies of philosophical explanation and drawing a general metaphilosophical moral from the foregoing discussion.