Imagine: one day you discover the ultimate truthwhat do you do? Of course you are delighted and enthusiastically want to share your discovery with the rest of the world. Your predecessors already published, after arduous research and a painstaking thinking process, all the little bits of truth which they had fished out of a nature thatas Heraclitus already knewlikes to hide (fr. 22 B 123 = Themistius, orat. 5,69b). Then, after this age-long tradition of careful searching, the day comes that light definitively breaks through and the decisive truth is found, a turning point in intellectual history. From that very moment on, there is no need for further discussions, as the clear truth is available to everyone. This is what happened at the end of the fourth century BC, and the 'divine mind' 1 who discovered the truth was Epicurus. For later followers such as Lucretius, his discoveries eclipsed all previous achievements. They were even more precious than the gifts of Ceres and Liber and more impressive than the labours of Hercules (5,13-54; cf. also 3,1-30). No wonder, then, that Epicurus also wished to communicate his insights to all other people. He addressed his letters to everyone, men and women alike, 2 to both young and old (cf. Epist. ad Men. 122), and to both upper and lower classes, including even slaves. 3 He even showed a fundamental openness to other philosophical traditions, provided that their doctrines were compatible with the truth he found out. 4 And this eagerness to divulge the Epicurean truth urbi et orbi was taken over by later followers throughout the history of the school. It still seems to have lost nothing of its original enthusiasm in the second century AD, when Diogenes of Oenoanda published his inscription for the sake of everyone: the young, the old, and those who are somewhere in between, 'not yet old, but not indeed young either' (fr. 29.III + NF 207.I.13 -NF 207.III.13), including not only Greeks but foreigners as well (fr.