Instructions 20Q Game: These are similar to full games, but for quizzes larger than 20 questions it will randomly select 20 questions from within the set. This is a quick way to get in some studying of a topic.     
Identify the following philosopher:

(1942-Present) American philosopher and professor at New York University. In "Ignorance" (1975), he argues that nobody knows anything and even that nobody is reasonable or justified in believing anything.
David Hume
Peter Unger
Aristotle
Friedrich Engels