Are there methods proposed to "measure" the complexity of a theory? either quantitatively or qualitatively. Let me explain with an example: I'd say that theories of the type of Hooke's law:
F = k.x
in which "the force (F) needed to extend or compress a spring by some distance X scales linearly with respect to that distance" Wiki. would be the simplest in the scale because it only contains a simple causal link.
On the other hand, plate theory with its Partial Differential Equations would be much more complex on the scale, since it has many more causal links and interrelations.
I've checked Rescher's Epistemetrics book, has interesting insights, but couldn't find something that addresses this. Any ideas?