Lucretius (99 or 94–55 B.C.), Roman poet, author of On the Nature of Things (De rerum natura), an epic poem in six books. Lucretius’s emphasis, as an orthodox Epicurean, is on the role of even the most technical aspects of physics and philosophy in helping to attain emotional peace and dismiss the terrors of popular religion. Each book studies some aspect of the school’s theories, while purporting to offer elementary instruction to its addressee, Memmius. Each begins with an ornamental proem and ends with a passage of heightened emotional impact; the argumentation is adorned with illustrations from personal observation, frequently of the contemporary Roman and Italian scene. Book 1 demonstrates that nothing exists but an infinity of atoms moving in an infinity of void. Opening with a proem on the love of Venus and Mars (an allegory of the Roman peace), it ends with an image of Epicurus as conqueror, throwing the javelin of war outside the finite universe of the geocentric astronomers. Book 2 proves the mortality of all finite worlds; Book 3, after proving the mortality of the human soul, ends with a hymn on the theme that there is nothing to feel or fear in death. The discussion of sensation and thought in Book 4 leads to a diatribe against the torments of sexual desire. The shape and contents of the visible world are discussed in Book 5, which ends with an account of the origins of civilization. Book 6, about the forces that govern meteorological, seismic, and related phenomena, ends with a frightening picture of the plague of 429 B.C. at Athens. The unexpectedly gloomy end suggests the poem is incomplete (also the absence of two great Epicurean themes, friendship and the gods). See also EPICURE – ANIS. D.Ar.