the 5th Century BCE, Greek philosophers of the Sophist School argued that all human beings are equal by nature.
Laws and institutions that failed to respect this basic equality, e.g. slavery, were thus branded as being
contrary to nature.
Both Plato and his disciple Aristotle, each in his own way, argued for a common nature of being human,
which is realized in a legally instituted community, i.e. the “polis”. Aristotle goes so far as to define
human being as a “social animal”, more specifically as a “political animal” (zoon politikon). The foundations
for living together as human beings are liberty, equality and justice. The civil society is a community of free
Platon and Aristotle,
detail from “The School of Athens”, by Raphael