The most savage controversies are those about matters as to which there is no good evidence either way.
All knowledge that the world has ever received comes from the mind; the infinite library of the universe is in our own mind.
Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.
Courage, conviction and confidence.
The first idea the child must acquire is that of the difference between good and evil.
The idea is to try to give all the information to help others to judge the value of your contribution; not just the information that leads to judgment in one particular direction or another.
There is nothing more notable in Socrates than that he found time, when he was an old man, to learn music and dancing, and thought it time well spent.
The progressive development of man is vitally dependent on invention.
Any sufficiently advanced technology is indistinguishable from magic.
The deepest sin against the human mind is to believe things without evidence.
Knowledge becomes evil if the aim be not virtuous.
A cynic is a man who knows the price of everything, and the value of nothing.
In mathematics you don't understand things. You just get used to them.
Real knowledge is to know the extent of one's ignorance.
Science is not only a disciple of reason but, also, one of romance and passion.
Educate the children and it won't be necessary to punish the men.
Reading without reflecting is like eating without digesting.
What is freedom of expression? Without the freedom to offend, it ceases to exist.
The fullness of knowledge only comes through the awareness of ignorance.
Science is a way of thinking much more than it is a body of knowledge.
That men do not learn very much from the lessons of history is the most important of all the lessons that history has to teach.