Quote by John Stuart Mill
"The very principle of true philosophy is to commence with doubt of everything which has been long received."
More from John Stuart Mill
"It is better to be a human being dissatisfied than a pig satisfied; better to be Socrates dissatisfied than a fool satisfied."
"The only freedom which deserves the name is that of pursuing our own good in our own way."
"Actions are right in proportion as they tend to promote happiness, wrong as they tend to produce the reverse of happiness."
"The person who can be only an easy optimist is a coward."