Talk (Work in Progress): John Dougherty (MCMP)

Title:

Symmetry and abstraction

Abstract:

Physicists and philosophers will often appeal to symmetry considerations when identifying the content of a physical theory. For example, they will argue that there is no fact of the matter regarding the absolute position of the solar system because the laws of physics are symmetric with respect to translation. Philosophers of science reflecting on these arguments have primarily sought sufficient conditions for their soundness–identifying the kinds of symmetries for which these arguments succeed and explaining their success. In this paper I investigate some necessary conditions on symmetry arguments that have been presupposed–usually implicitly–in this literature. In particular, I argue that interpreters of physical theories have generally assumed a completeness condition analogous to that which for Frege generated his "Julius Caesar problem". Reflection on this problem suggests weakenings of the completeness condition, and I show that these weakenings open up valuable conceptual real estate.