The same things are best both for individuals and for states, and these are the things which the legislator ought to implant in the minds of his citizens.
In our daily life a certain way of thinking makes us happy, and a certain way of thinking makes us unhappy. In other words, there are certain states of mind which bring us problems, and they can be removed.
The mind commands the body, and it obeys forthwith; the mind commands itself, and is resisted. The mind commands the hand to be moved, and such readiness is there that the command is scarce to be distinguished from the obedience. Yet the mind is mind, and the hand is body. The mind commands the mind to will, and yet, though it be itself, it obeyeth not. Whence this monstrous thing? and why is it?