Pleasure causes us to do base actions and pain causes us to abstain from doing noble actions.
AristotleWe have no evidence as yet about mind or the power to think; it seems to be a widely different kind of soul, differing as what is eternal from what is perishable; it alone is capable of existence in isolation from all other psychic powers.
AristotleThe sun, moving as it does, sets up processes of change and becoming and decay, and by its agency the finest and sweetest water is every day carried up and is dissolved into vapour and rises to the upper region, where it is condensed again by the cold and so returns to the earth. This, as we have said before, is the regular course of nature.
AristotleSome persons hold that, while it is proper for the lawgiver to encourage and exhort men to virtue on moral grounds, in the expectation that those who have had a virtuous moral upbringing will respond, yet he is bound to impose chastisement and penalties on the disobedient and ill-conditioned, and to banish the incorrigible out of the state altogether. For (they argue) although the virtuous man, who guides his life by moral ideals, will be obedient to reason, the base, whose desires are fixed on pleasure, must be chastised by pain, like a beast of burden.
Aristotle