"Philosophy goes no further than probabilities, and in every assertion keeps a doubt in reserve."

"Age does not make us childish, as some say; it finds us true children."

"Human improvement is from within outward."

"The practical effect of a belief is the real test of its soundness."

"In everyday things the law of sacrifice takes the form of positive duty."

"Instruction does not prevent wasted time or mistakes; and mistakes themselves are often the best teachers of all."

"No person is ever good for much, that hasn't been swept off their feet by enthusiasm between ages twenty and thirty."

"Experience teaches slowly, and at the cost of mistakes."

"As we advance in life, we learn the limits of our abilities."

"The secret of a person's nature lies in their religion and what they really believes about the world and their place in it."

"A person possessed with an idea cannot be reasoned with."

"Fear is the parent of cruelty."

"To deny the freedom of the will is to make morality impossible."

"The essence of greatness is neglect of the self."

"The better one is morally the less aware they are of their virtue."

"The endurance of the inequalities of life by the poor is the marvel of human society."

"Superior strength is found in the long run to lie with those who had right on their side."

"The first duty of an historian is to be on guard against his own sympathies."

"We enter the world alone, we leave the world alone."

"Wild animals never kill for sport. Man is the only one to whom the torture and death of his fellow creatures is amusing in itself."

"Science rests on reason and experiment, and can meet an opponent with calmness; but a belief is always sensitive."

"You cannot dream yourself into a character; you must hammer and forge yourself one."