* When one discusses someone (say, John Doe), one might ask "what" John Doe is. " The answer would be a human being (a creature with a mind/[[nous]], a body, and a life). * If, however one asked "what" John Doe does, " that would be a different question. The answer might be running, building, teaching, etc. Note that we may often say John Doe ''is'' a runner, builder, or teacher; but such is simply a method of speaking. These attributes (all acquired through time) have no relation to what John Doe actually ''is'' (i.e. a human being). * Both of those questions, however, are different from "who" John Doe is. " The answer to "who John Doe is," is what makes John Doe different from Jim Doe (or Jane Doe, etc.). This is a specific person who distinctly uses the characteristics he/she shares with others (ex. sharing the same humanity, but also perhaps the same activity, like running).