A fool thinks himself to be wise, but a wise man knows himself to be a fool.
William Shakespeare
Wise men speak because they have something to say; Fools because they have to say something. Plato
A wise man can learn more from a foolish question than a fool can learn from a wise answer. Bruce Lee
The stupid neither forgive nor forget; the naive forgive and forget; the wise forgive but do not forget.
Thomas Szasz
A smart man only believes half of what he hears, a wise man knows which half.
Jeff Cooper
Talking and eloquence are not the same: to speak and to speak well are two things. A fool may talk, but a wise man speaks.
Heinrich Heine