atomic films (εἴδωλa, simulacra), similar in shape to the object, to be discharged at high speed from its surface. When these strike our eyes, they produce vision; when they are received by our mind, they cause thought or, if we are asleep, dreams (Lucr. 4.26-521, 722-822, 877-906, 962-1036). All sensation involves physical contact between the object perceived and the body of the perceiver: in the case of taste (Lucr. 4.615-632) and touch the contact is direct; but in the case of hearing (Lucr. 4.524-614) and smell (Lucr. 4.673-705), as in the case of vision, the contact is indirect, being effected by emanations impinging on the appropriate sense-organ.

The mind and soul are material and therefore mortal. Lucretius demonstrates their nature and composition, and proves that they are born with the body and die with the body, in 3.94-829. The mind (animus), which is the seat of emotion as well as of thought, has its fixed place in the breast, and is to be distinguished from the soul or spirit (anima), the seat of sensation, which is scattered all through the body. But both are composed of the same kind of very fine, small, round, mobile particles. The proof that mind and soul are corporeal and mortal, and that there is no sensation in death, is extremely important, for fear of death is one of the two great fears which prevent the attainment of tranquillity; and so Lucretius, having completed his long proof, at once launches into that inspired passage (3.830-1094) whose theme is stated in the first line (3.830):

nil igitur mors est ad nos neque pertinet hilum.

Epicureanism’s materialistic psychology and denial of an after-life was one of the main reasons why the


philosophy was so fiercely attacked, especially in Christian times. It may also have been one of the main reasons why, after withstanding the challenge of Christianity for nearly four centuries, it eventually lost the battle: Christianity’s offer of immortal life probably seemed more appealing and comforting than Epicureanism’s promise of a mors . . . inmortalis (Lucr. 3.869) in which there is no consciousness. Other matters which provoked the hostility of Christianity were Epicurus’ theological and ethical doctrines.

Epicurus has often been called an atheist and an enemy of religion. In fact, he was a firm believer in the existence of the gods, and was opposed not to all religion, but only to what he regarded as false religion. The existence of the gods is certain, for our knowledge of them is derived from clear perception (Ep. ad Men. 123). But what is their nature, where do they live, and how do we perceive them? They are material beings, but their atomic composition is exceedingly fine and they differ from other compound bodies in that they are immune to destruction. They live not in our world, but in parts which are as tenuous as their bodies (Lucr. 5.146-154)—that is, in the spaces between the worlds (μετακόσμια, intermundia), where all is peace and the climate is perfect (Lucr. 3.18-22). Perfectly self-sufficient, tranquil, and happy (Lucr. 1.44-49, 2.646-651), they have neither the inclination nor the power to intervene in the affairs of a world which they did not create. They are never angry (Lucr. 1.49, 2.651, 6.74), and violent and irregular phenomena such as thunder and lightning, earthquakes and volcanoes are certainly not sent by them to punish