Education must have two foundations, morality and carefulness: morality to support virtue; carefulness to defend against others' vices. By inclining this balance to the side of morality, you only make dupes and martyrs; by inclining it to carefulness, you make calculating egoists. The principle of all society is to do justice to oneself and to others. If it is right to love the person next to us as ourselves, it is at least as right to love ourselves as much as the people next to us.