Advances in the natural sciences had reduced fire from an act of witchcraft to a comprehendible occurrence of rapid oxidation. Advances in philosophical and political sciences had elevated the concept of government from the bondage of the aristocracy to the freedom of self-government and the rule of law. And the Enlightenment found its legitimacy in the proof of logic. In order for these theories to became valid and widely accepted they had to be proved true. The progression of this thought process is a fairly straight line.
Observation creates an idea.
The idea is formalized into a theory. The theory is tasked with the burden of proof. If the proof validates the theory, a truth results. It is simple logic. This logic is the basis of every beneficial product of society.