I call that law universal, which is conformable merely to dictates of nature; for there does exist naturally an universal sense of right and wrong, which, in a certain degree, all intuitively divine, even should no intercourse with each other, nor any compact have existed.
Bad people...are in conflict with themselves; they desire one thing and will another, like the incontinent who choose harmful pleasures instead of what they themselves believe to be good.
The legislator should direct his attention above all to the education of youth; for the neglect of education does harm to the constitution. The citizen should be molded to suit the form of government under which he lives. For each government has a peculiar character which originally formed and which continues to preserve it. The character of democracy creates democracy, and the character of oligarchy creates oligarchy.
Humor is the only test of gravity, and gravity of humor; for a subject which will not bear raillery is suspicious, and a jest which will not bear serious examination is false wit.
Tyrants preserve themselves by sowing fear and mistrust among the citizens by means of spies, by distracting them with foreign wars, by eliminating men of spirit who might lead a revolution, by humbling the people, and making them incapable of decisive action.
The seat of the soul and the control of voluntary movement - in fact, of nervous functions in general, - are to be sought in the heart. The brain is an organ of minor importance.