The saying of Protagoras is like the views we have mentioned; he said that man is the measure of all things, meaning simply that that which seems to each man assuredly is. If this is so, it follows that the same thing both is and is not, and is bad and good, and that the contents of all other opposite statements are true, because often a particular thing appears beautiful to some and ugly to others, and that which appears to each man is the measure
AristotleThe virtue as the art consecrates itself constantly to what's difficult to do, and the harder the task, the shinier the success.
AristotleNeither should men study war with a view to the enslavement of those who do not deserve to be enslaved; but first of all they should provide against their own enslavement, and in the second place obtain empire for the good of the governed, and not for the sake of exercising a general despotism, and in the third place they should seek to be masters only over those who deserve to be slaves.
AristotleA tragedy is a representation of an action that is whole and complete and of a certain magnitude. A whole is what has a beginning and middle and end.
Aristotle