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:

(1806-1873) British philosopher and political economist. Dubbed "the most influential English-speaking philosopher of the nineteenth century". His conception of liberty justified the freedom of the individual in opposition to unlimited state and social control.
Marcus Aurelius
Democritus
John Stuart Mill
Jean-Paul Sartre