The knowledge of yourself will preserve you from vanity. — Miguel de Cervantes

In friendship as well as love, ignorance very often contributes more to our happiness than knowledge. — Francois de La Rochefoucauld
Only on paper has humanity yet achieved glory, beauty, truth, knowledge, virtue, and abiding love. — George Bernard Shaw
The man of knowledge must be able not only to love his enemies but also to hate his friends. — Friedrich Nietzsche
That's the nature of women, not to love when we love them, and to love when we love them not. — Miguel de Cervantes
He who loses wealth loses much; he who loses a friend loses more; but he that loses his courage loses all. — Miguel de Cervantes
To withdraw is not to run away, and to stay is no wise action, when there's more reason to fear than to hope. — Miguel de Cervantes