Believe me, many things are attributed to gravity and wisdom which are really due to incapacity and sloth. Men often despise what they despair of obtaining. It is in the very nature of ignorance to scorn what it cannot understand, and to desire to keep others from attaining what it cannot reach. Hence the false judgments upon matters of which we know nothing, by which we evince our envy quite as clearly as our stupidity.
To the Greeks not just slaves had to be excluded from the democratic franchise and public debate but also merchants, bankers, all money-grubbing banausoi, because any society stupid enough to entrust its ultimate values to be determined by the caste of utilitarians deserves fully what it gets. It would be like entrusting our sports to couch potatoes and paraplegics. Such a foolish society would get what we have in fact got, a civilization too fucking stupid to realize how hard cultural, political, spiritual and philosophical cripples labor to cripple everyone else to become just like them.