Late in my senior year, I went through a crisis of doubt when my provisional girlfriend, a willowy physics major named Morgan Piziks, informed me at the end of our fourth date that anybody seriously in the question "Why?” should look not to philosophy but to the physical sciences-to cosmology, quantum mechanics, molecular biology, and the periodic table of the elements.
My mind went blank. Try as I might, I could contrive no riposte. I felt instinctively that Morgan's claim enjoyed the nontrivial virtue of being true.