"Lives and Opinions of Eminent Philosophers" by Diogenes Laertius

Lives and Opinions of Eminent Philosophers by Diogenes Laertius (circa 300AD) is a biography of major Greek philosophers, including Book 10 on Epicurus. Contained within are:
  • A letter from Epicurus to Herodotus entitled “A Summary of Physical Nature”
  • A letter from Epicurus to Pythocles entitled “A Summary of Phenomena of the Sky”
  • A letter from Epicurus to Menoeceus entitled How to Live a Happy Life
  • The last will of Epicurus, outlining his final thoughts and disposition of his assets (and care of the children)
  • The Principle Doctrines

Herbert Long says in the introduction to his 1972 translation, “Diogenes has acquired an importance out of all proportion to his merits because the loss of many primary sources and of the earlier secondary compilations has accidentally left him the chief continuous source for the history of Greek philosophy.”

Nevertheless, Lives is one of the primary sources for ancient Greek philosophy. Diogenes was at least a fan of Epicurus, if not an Epicurean. Regarding Epicurus, Diogenes writes:

“our philosopher has abundance of witnesses to attest his unsurpassed goodwill to all men – his native land, which honoured him with statues in bronze; his friends, so many in number that they could hardly be counted by whole cities … the School itself which, while nearly all the others have died out, continues for ever without interruption through numberless reigns of one scholarch after another; his gratitude to his parents, his generosity to his brothers, his gentleness to his servants … and in general, his benevolence to all mankind.”

You can read the entire text of Book X on Wikisource1.

You can read more about the book here on Wikipedia2.

1 Lives of the Eminent Philosophers/Book X, (last visited Jan. 6, 2022).

2 Lives and Opinions of Eminent Philosophers, (last visited Jan. 6, 2022).