Epicurus (341-271 BC) was a Greek philosopher, a follower of Democritus and founder of Epicureanism, which is teaching focused on the search for happiness and wisdom. Epicurus was perhaps the earliest radical believer in human equality, certainly in the western world. He allowed women and slaves to attend his school because he saw no distinction.
Epicureanism
A system of philosophy based on the teachings of Epicurus, founded in around 307 BC. It teaches that the greatest good is to seek modest pleasures in order to attain a state of tranquillity, freedom from fear (“ataraxia”) and absence from bodily pain (“aponia”).

Of all the things which wisdom provides to make us entirely happy, much the greatest is the possession of friendship.