Also our fellow competitors, who are indeed the people just mentioned - we do not compete with men who lived a hundred centuries ago, or those yet not born, or the dead, or those who dwell near the Pillars of Hercules, or those whom, in our opinion or that of others, we take to be far below us or far above us. So too we compete with those who follow the same ends as ourselves; we compete with our rivals in sport or in love, and generally with those who are after the same things; and it is therefore these whom we are bound to envy beyond all others. Hence the saying.
AristotleMetaphysics involves intuitive knowledge of unprovable starting-points concepts and truth and demonstrative knowledge of what follows from them.
AristotleFor man, when perfected, is the best of animals, but, when separated from law and justice, he is the worst of all; since armed injustice is the more dangerous, and he is equipped at birth with the arms of intelligence and with moral qualities which he may use for the worst ends. Wherefore, if he have not virtue, he is the most unholy and the most savage of animals, and the most full of lust and gluttony. But justice is the bond of men in states, and the administration of justice, which is the determination of what is just, is the principle of order in political society.
Aristotle