The savage lives within himself; social man lives always outside himself; he knows how to live only in the opinion of others, it is, so to speak, fro… - Jean-Jacques Rousseau

"The "sociable" man, always outside himself, is capable of living only in the opinions of others and, so to speak, derives the sentiment of his own existence solely from their judgment."

In fact, the real source of all those differences, is that the savage lives within himself, whereas the citizen, constantly beside himself, knows only how to live in the opinion of others; insomuch that it is, if I may say so, merely from their judgment that he derives the consciousness of his own existence.

As soon as we have contrived to give our pupil an idea of the word "Useful," we have got an additional means of controlling him, for this word makes a great impression on him, provided that its meaning for him is a meaning relative to his own age, and provided he clearly sees its relation to his own well-being. This word makes no impression on your scholars because you have taken no pains to give it a meaning they can understand, and because other people always undertake to supply their needs so that they never require to think for themselves, and do not know what utility is. "What is the use of that?"

Su principal deber es procurar su propia conservación, sus principales cuidados son los que se debe a sí mismo; y después que adquiere uso de razón, siendo él sólo el juez de los medios propios para conservarse, llega a ser por este motivo su propio dueño.

With a long enough lever, the world could be moved with a single finger; to sustain it needs the shoulders of Hercules