Part 3 of 3. What makes you the same person as the little kid growing up a number of years ago?  Is the identity of a person tied to the persistence of a body or a soul or something else entirely?  Can we even given any explanation at all of the persistence of a person?  Michael Della Rocca (Yale University) explores some of the puzzles and problems of personal identity that arise from the revolutionary work of the philosopher John Locke.