Principal Doctrines & Letter to Menoeceus by Epicurus and translated by Robert Drew Hicks. Epicurus was an ancient Greek philosopher who founded a school of philosophy now called Epicureanism. Only a few fragments and letters of Epicurus's 300 written works remain. Much of what is known about Epicurean philosophy derives from later followers and commentators. The "Principal Doctrines", also known as the "Sovran Maxims", are a collection of forty quotes from the writings of Epicurus that summarize his ethical theory. The "Letter to Menoeceus" summarizes his ethical doctrines. 'Let no one be slow to seek wisdom when he is young nor weary in the search thereof when he is grown old. For no age is too early or too late for the health of the soul. And to say that the season for studying philosophy has not yet come, or that it is past and gone, is like saying that the season for happiness is not yet or that it is now no more.'