Montesquieu Quote

Democratic and aristocratic states are not in their own nature free. Political liberty is to be found only in moderate governments; and even in these it is not always found. It is there only when there is no abuse of power. But constant experience shows us that every man invested with power is apt to abuse it, and to carry his authority as far as it will go. Is it not strange, though true, to say that virtue itself has need of limits?

De l'Esprit des Lois (1748)