A mature science is governed by a single paradigm. - Alan Chalmers

No matter which comes first, the facts or the theory, the question to be addressed is the extent to which the theory is borne out by the facts. The strongest possible claim would be that the theory can be logically derived from the facts. That is, given the facts, the theory can be proven as a consequence of them. This strong claim cannot be substantiated.

Science progresses by trial and error, by conjectures and refutations. Only the fittest theories survive.

Scientists are typically good at making scientific progress, but not particularly good at articulating what the progress consists of.