Rationality Personified

Rationality is cold, detached.  He looks at a kitten snuggling with its mother and says, "The kitten just wants food and protection."  He is not fun at parties, and isn't afraid to trample other's feelings for the greater good.  Puzzles and riddles are the ultimate thrill for him.  He practically lives at the library, poring over books, subsiding only on the food from the library cafe.