Epicurius was "at the same time one of the most revered and most reviled of all founders of thought in the Graeco-Roman world." He taught that the physical world was all there was, that it had always existed and would last forever. Not only was there no Creator, there was no God in charge of the universe to give life purpose. Men simply lived and then died - so while he is alive a man should seek to maximise pleasure and minimise pain. Such teaching resulted in his teaching being attacked by Platonist, Stoic and Christian alike, indeed many of the criticisms of the Epicureans found in the writings of the early church fathers are simply rehearsals of the attacks of earlier writers.
Despite the accusations of his enemies Epicurius was an intelligent man who, having discovered what he believed to be the truth, determined to share that knowledge with everyone. In so doing he created the first world philosophy which appealed both to Greeks and non-Greeks. His activity may even have served to aid the spread of the Gospel.
Epicurius opposed Platonism (then the dominant philosophy), seeking to revive the physical theories of the Ionian philosophers, especially those of Democritus. Influenced by the flood of information that Aristotle and his contemporaries had gathered about the world, he made the senses, rather than reason the test of truth. If the senses appeared to be wrong, then "the mistakes were not in the sense but in reason, which made a mistaken inference from the sense data."
Instead of listing the tenets of the Epicurean atomic theory (which have been well summarised elsewhere) we will look at what his School taught about the origin of life on earth. In our study we are fortunate that besides the small number of Epicurius works that survive we also have an exposition of the Epicurean system by the Roman poet Lucretius (94-55 BC). From these we learn that this world is the result of the chance collision of atoms, there is no room for any concept of a divine power involved in creation in the Epicurean system. Lucretius points to the imperfection of the present world as evidence of this. Over a tremendous period of time a whirlwind of randomly moving atoms began to sort themselves out. The heaviest settled to the centre of the whirlwind, forming the earth. The lighter ones formed the sea, sun, moon and stars. As the atoms became compressed the earth shrank and salt water was forced out onto the surface forming he seas. Plants and trees sprang spontaneously from the new-formed earth, next animals formed from the effect of the sun upon the earth.
There was a great superfluity of heat and moisture in the soil. So, wherever a suitable spot occurred, there grew up wombs, clinging to the earth by roots. These, when the time was ripe, were burst open by the maturation of the embryos, rejecting moisture now and struggling for air. Then nature directed towards the spot the pores of the earth, making it open its veins and exude a juice resembling milk The young were fed by the earth, clothed by the warmth and bedded by the herbage, which was then covered by an abundance of soft down. The childhood of the earth provoked no hard frosts or excessive heats or winds of boisterous violence. For all things keep pace in their growth and attainment of their full strength.
The process was far from perfect, as Lucretius describes:
In those days the earth attempted also to produce a host of monsters, grotesque in build and aspect - hermaphrodites, halfway between the sexes yet cut off from either, creatures bereft of feet of disposed of hands, dumb, mouthless brutes, or eyeless and blind, or disabled by the adhesion of their limbs to the trunk, so, that they could neither do anything nor go anywhere nor keep out of harms way nor take what they needed. These and other such monstrous and misshapen births were created. But all in vain. Nature debarred them from increase. In those days, again, many species must have died out altogether and failed to reproduce their kind. Every species that you now see drawing the breath of life has been protected and preserved from the beginning of the world either by cunning or by prowess or by speed.
So, according the Lucretius, the living world formed spontaneously, and developed into its present form by survival of the fittest. He is adamant that creatures of legend, such as the Centaur, Chimera and Scyllas (combinations of two animals) were completely fictional. Lucretius does not distinguish the emergence of mankind from that of the animals. As the earth grew older and was no longer able to spontaneously produce offspring. With the passage of time the bodies of men became weaker and they learned how to build, make fires and began to live in families and form alliances with one another.
Given the details of the Epicurean teaching on the origin of the universe it is not altogether surprising that Epicurius are seen as champions of Evolution by some writers. It is worth noting, however, that the Epicurean theories were not based upon any empirical evidence.
 Norman Wentworth DeWitt, Epicurius and His Philosophy. (Minneapolis: University of Minnesota Press, 1954), 3
 Everett Ferguson, Backgrounds of Early Christianity, 2nd edn. (Grand Rapids: Eerdmans, 1993), 353.
 DeWitt, 3
 DeWitt, 8: "Epicureanism served in the ancient world as a preparation for Christianity, helping to bridge the gap between Greek intellectualism and a religious way of life. It shunted the emphasis from a political to the social virtues and offered what may be called a religion of humanity. The mistake is to overlook the terminology and ideology of Epicureanism in the New Testament and to think of its founder as an enemy of religion.
 DeWitt, 15
 Everett Ferguson, Backgrounds of Early Christianity, 2nd edn. (Grand Rapids: Eerdmans, 1993), 352
 DeWitt, 156-157; Everett Ferguson, Backgrounds of Early Christianity, 2nd edn. (Grand Rapids: Eerdmans, 1993), 350-352; Benjamin Farrington, The Faith of Epicurius (London: Weidenfeld and Nicolson, 1967), 112-113.
 Lucretius, On the Nature of the Universe, trans. R.E. Latham, 1951. (Harmondsworth: Penguin, 1973), 175-177
 Lucretius, 177
 Lucretius, 184-186
 Lucretius, 195
 Lucretius, 195-197
 Lucretius, 195-196. Italics in original translation
 Lucretius, 198; J.M. Rist, Epicurius: An Introduction. (Cambridge: Cambridge University Press, 1972), 70-71.
 Rist, 71.
 Lucretius, 196
 Lucretius, 202
 O.E. Lavenstein, "The Pre-Socratics, Lucretius, and Modern Science," D.R. Dudley, Lucretius. (London: Routledge & Kenan Paul, 1965), 13.
|Cyril Bailey, The Greek atomists and Epicurus, a study. Oxford: Clarendon Press, 1928. Reprinted: New York: Russell & Russell, 1964. ISBN: 0846204274. pp.619.|
|John Gaskin, The Epicurian Philosophers. Tuttle Publishing, 1994. Pbk. ISBN: 0460876074.|
|R. Jungkuntz, "Christian Approval of Epicurianism," Church History, Vol. 31 (1962): 279-293.|
|R. Jungkuntz, "Fathers, Heretics and Epicureans," Journal of Ecclesiastical History, Vol. 17 (1966): 3-10.|
|P.H. de Lacy, "Lucretius and the History of Epicureanism," Transactions of the American Philological Association 79 (1948): 12-23.|
|A.D. Simpson, "Epicureans, Christians, Atheists in the Second Century," Transactions of the American Philological Association 72 (1941): 372-381.|
|N.W. de Witt, "Notes on the History of Epicurianism," Transactions of the American Philological Association 63 (1932): 166-176.|
|N.W. de Witt, St. Paul and Epicurus. Minneapolis: University of Minnesota Press, 1956.|