Question: What is a (or the) scientific theory V based on a set B of syntactical L-formulas, interpreted according to the intended interpretations of the language L? What probably corresponds to the traditional candidate for V is found to be inadequate for use in deductively explaining experimental facts of a certain form. A second candidate for V, called a strong scientific theory (SST), does not suffer such an inadequacy because it is existentially strong, i.e., it has considerable existential import. It (...) even satisfies the particle physicist's dictum: WHAT IS NOT FORBIDDEN WILL HAPPEN. (shrink)

Moulines in his "A Logical Reconstruction of Simple Equilibrium Thermodynamics" shows that Sneedian constraints play an essential role even in the purely theoretical development of the mathematical formalism of at least one actual scientific theory. However, Moulines' treatment is apparently inconsistent because of the way he represents constraints. A very simple non-Sneedian way of representing constraints is given which removes the difficulty.