Great spirits have always encountered violent opposition from mediocre minds.

The most important knowledge is that which guides the way you lead your life.

Life consists in penetrating the unknown, and fashioning our actions in accord with the new knowledge thus acquired.

What is important is not the quantity of your knowledge but its quality. You can know many things without knowing the most important.

The only absolute knowledge attainable by man is that life is meaningless.

We know more about the movement of celestial bodies than about the soil underfoot.