thorough general education requirement on the scientific approach to society would require two courses. First, students should take a course that teaches the crafting of rigorous hypotheses. ...
Second, students should take a class on evidence and statistical inference. This could either be pure statistics or empirical tools taught through the lens of a particular topic. Decent citizenship of the world is incompatible with statistical ignorance.
I am a big fan, as is Steven Pinker, of education in statistics. Thanks to computers, which store lots of data to feed statistical models and which use statistical methods to solve many important classes of problems, statistics is growing in importance. If you think that calculus is anywhere near as important to know as statistics, I believe you are at least a generation out of date.
Speaking of statistics, if I were looking at Harvard's curriculum decision problem, I would focus on data. Suppose that you had a ranking for the students in the most recent graduating classes that told you how well they turned out in terms of critical thinking skills. What is the correlation between the courses that a student took and his or her ranking? If there is no correlation, then maybe curriculum does not matter. If there is a strong correlation, then maybe the courses that are correlated with high thinking skills belong in the core curriculum.
If Glaeser and Harvard are serious about the value of empiricism in the curriculum, then they should base the curriculum on some empirical data. I know that correlation is not causation, but then, neither is guesswork. Eh, Professor Mankiw?