The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane.

— Marcus Aurelius

Judge a man by his questions rather than his answers.

— Voltaire

The highest activity a human being can attain is learning for understanding, because to understand is to be free.

— Baruch Spinoza

The wise man doesn’t give the right answers, he poses the right questions.

— Claude Lévi-Strauss

To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge.

— Confucius

The most certain sign of wisdom is cheerfulness.

— Michel de Montaigne

All things must be examined, debated, investigated without exception and without regard for anyone’s feelings.

— Diderot