“The authority of those who teach is often an obstacle to those who want to learn.”

“Few are those who wish to be endowed with virtue rather than to seem so.”

“As for myself, I can only exhort you to look on Friendship as the most valuable of all human possessions, no other being equally suited to the moral nature of man, or so applicable to every state and circumstance, whether of prosperity or adversity, in which he can possibly be placed. But at the same time I lay it down as a fundamental axiom that "true Friendship can only subsist between those who are animated by the strictest principles of honour and virtue." When I say this, I would not be thought to adopt the sentiments of those speculative moralists who pretend that no man can justly be deemed virtuous who is not arrived at that state of absolute perfection which constitutes, according to their ideas, the character of genuine wisdom. This opinion may appear true, perhaps, in theory, but is altogether inapplicable to any useful purpose of society, as it supposes a degree of virtue to which no mortal was ever capable of rising.”

“Diseases of the soul are more dangerous and more numerous than those of the body.”

“To teach is a necessity, to please is a sweetness, to persuade is a victory.”

“He only employs his passion who can make no use of his reason.”

“They who say that we should love our fellow-citizens but not foreigners, destroy the universal brotherhood of mankind, with which benevolence and justice would perish forever”