"The chief cause of human error is the confused nature of our perceptions."

"I resolved to seek no other knowledge than that which I might find within myself, or in the great book of the world."

"The greatest good is to live without pain."

"He who has a firm and stable mind will find that in all conditions of life he can be master of himself."

"It is not enough to apply our mind to things, but we must also apply it to ourselves."