I think if you had to break it down, it is reducible to the distinction between principle and beliefs. A principled man uses rational maxims to bring order to the natural universe. Principle is not about holding passionately to some set of convictions. That sort of primacy of subjective belief systems is how Protestantism deformed our Enlightenment republic. People figure that if you believe something to the bottom of your soul, you are at least entitled to some respect.
But principle does not work that way. There is nothing inherently respectable, about something believed, no matter how widespread or heartfelt. The metric for respectability, to a man of principle, is rational objectivity. So this is not "empirical reasoning" vs.