. >> sophia rosenfeld, what's the definition of common sense in politics? >> guest: good question to start off with. the one thing we never talk about common sense, we refer to it all the time, but it's not something that gets defined very often. common sense is supposed to be, at least, the kind of thing you don't have to talk about. it's the wisdom everybody has, it's the obvious, the self-evident. and it's something politicians refer to a lot. if you ever note that democrats or republicans, they love to talk about a common sense solution to health care or common sense solution to the problems of the environment. but nobody ever actually sits down and what is common sense, what would it be? it's the everyday, ordinary wisdom, reasoning about everyday, ordinary matters that we're supposed to, basically, agree upon without discussion. >> host: when did it enter, that term enter the political kiss course? >> guest: well, it's a very old term. the term goes all the way back to aristotle in different forms. it's a faculty of the brain. but starting in the earl