Of the Nature of Things (De Rerum Natura) was Roman philosopher Lucretius' first century didactic poem spanning six books, painstakingly transcribed on papyrus rolls and stored in circumspect for centuries. It explains the tenets of Epicureanism, a belief in striving for pleasure without pain (a form of hedonism), seeking knowledge of the workings of the world (atomism), and understanding the nature of the mind and soul to achieve a state of tranquility in this life, which is the only one that exists. The Church violently opposed Epicureanism as the antithesis of Christian beliefs, and set to destroy Lucretius' writings, with such inflammatory chapters as "Nothing Exists per se Except the Atom and the Void" and "The Soul is Mortal." The poem was given up as lost during the Middle Ages, but rediscovered in the Age of Enlightenment, when Epicureanism was revived.
Book I - Nothing Exists per se Except Atoms and the Void
Book I - Characters of the Atoms
Book I - Confutation of Other Philosophers
Book I - The Infinity of the Universe
Book II - Atomic Forms and Their Combinations
Book III - Nature and Composition of the Mind
Book III - Folly of the Fear of Death
Book IV - Existence and Character of the Images
Book IV - The Senses and Mental Pictures
Book IV - Some Vital Functions
Book V - The World Is Not Eternal
Book V - Origins of Vegetable and Animal Life
Book V - Origins and Savage Period of Mankind
Book V - Beginnings of Civilization
Book VI - Great Meteorological Phenomena, Etc.