Without freedom of thought, there can be no such thing as wisdom - and no such thing as public liberty without freedom of speech.
Courage is rightly esteemed the first of human qualities... because it is the quality which guarantees all others.
Ethical axioms are found and tested not very differently from the axioms of science. Truth is what stands the test of experience.
Results! Why, man, I have gotten a lot of results. I know several thousand things that won't work.
If I find 10,000 ways something won't work, I haven't failed. I am not discouraged, because every wrong attempt discarded is another step forward.
Prejudice is a burden that confuses the past, threatens the future and renders the present inaccessible.
All the great things are simple, and many can be expressed in a single word: freedom, justice, honor, duty, mercy, hope.
As an elephant in the battlefield withstands arrows shot from bows all around, even so shall I endure abuse.
Few people are capable of expressing with equanimity opinions which differ from the prejudices of their social environment. Most people are even incapable of forming such opinions.