The "triumph of reason" as you describe it came from philosophy. It was the "natural philosophers" who developed the style of critical thinking and rationality that resulted in the Enlightenment and Scientific Revolution. Of course, there is plenty of bad thinking that gets categorized under the name philosophy, but that doesn't mean that the whole enterprise is useless.

Actually, I think philosophy should be taught more in schools. Learning to understand, evaluate, and critique complex arguments is just as important, if not more important, than learning to solve equations or do empirical science.