There is no such thing as "being smart". You can be arbitrarily good at some things, and arbitrarily bad at anything else. Even the greatest physicists can have laughably naive philosophical positions. Linus Paulding, one of the greatest minds in chemistry in history, was convinced that you can cure virtually any disease with a large enough dose of vitamin C. Expertise, even the extreme peak, in one field doesn't give you expertise of any kind in another field.