How empirical was Adam Smith's The Wealth of Nations? What about some other "big books"?
That is, how much empirical research does it contain?
And thus, what kind of "epistemological accuracy" does it have?
Motive:
I want to understand whether books that are regarded as "standards" in political science and economics are actually "scientific" in the sense that they contain empirical proof for the theses that they put forward. Since I speculate that some portion of "economic belief" is "a priori opinion" or "normative statements" (what ought to be vs. what is).
Empirical research is more valid than philosophical, when the theses deal with things that are claimed to exist in other ways than mere beliefs. Empirical research (in the humanities) thus means validating theses through studying how people actually behave or formulating theses based on observing people.