A little learning is a dangerous thing.
Extremes in nature equal ends produce; In man they join to some mysterious use.
Let such teach others who themselves excel, And censure freely who have written well.
Genius involves both envy and calumny.
Persons of genius, and those who are most capable of art, are always most fond of nature: as such are chiefly sensible, that all art consists in the imitation and study of nature.
Find, if you can, in what you cannot change. Manners with fortunes, humours turn with climes, Tenets with books, and principles with times.