For nature by the same cause, provided it remain in the same condition, always produces the same effect, so that either coming-to-be or passing-away will always result.
AristotleOur virtues are voluntary (and in fact we are in a sense ourselves partly the cause of our moral dispositions, and it is our having a certain character that makes us set up an end of a certain kind), it follows that our vices are voluntary also; they are voluntary in the same manner as our virtues.
AristotleThere are, then, these three means of effecting persuasion. The man who is to be in command of them must, it is clear, be able (1) to reason logically, (2) to understand human character and goodness in their various forms, and (3) to understand the emotions--that is, to name them and describe them, to know their causes and the way in which they are excited.
AristotleNow if there is any gift of the gods to men, it is reasonable that happiness should be god-given, and most surely god-given of all human things inasmuch as it is the best. But this question would perhaps be more appropriate to another inquiry; happiness seems, however, even if it is not god-sent but comes as a result of virtue and some process of learning and training, to be among the most god-like things; for that which is the prize and end of virtue seems to be the best thing in the world, and something god-like and blessed.
Aristotle