Gilbert Highet (1906-1978), The Classical Papers
, ed. Robert J. Ball (New York: Columbia University Press, 1983), pp. 108-109:
The material of the world is not what it seems to be. A solid, like a rock, or a fluid, like water, is only apparently solid or fluid. Both the rock and the water are composed of myriads of invisible particles which are associated by laws of their own and are in constant movement.
This earth and the sun and moon and planets, all our universe, in fact, is made up of atoms. The atoms came together to form them, as tiny drops of water come together to form a river. In time, the atoms will separate again, and our universe will cease to exist, as a river does when it runs into the desert and evaporates. But the atoms will never cease to exist. They, and they alone, are eternal.
Earthquakes, volcanic eruptions, epidemics, and such disasters are not caused by God's anger. They are natural phenomena and can be explained scientifically.
Sensation and thought are functions of the body. The soul is not immortal, but is born in the body, develops with it, and will cease to exist when the other physical functions, such as respiration, and heartbeat, stop.
Of these four propositions, most civilized people in the Western world nowadays believe the first and the third. Many believe the second. Some believe the fourth. All four were accepted as unquestionable truth by many Greeks and Romans; they became the theme of a magnificent Latin poem; they were maintained for at least five centuries; and thereafter, for a thousand years, they were buried in oblivion. The first and second, if anyone had even thought of them in the Middle Ages, would have been dismissed as ridiculous; the third and fourth as blasphemous. And yet the Latin poem built on these statements somehow survived.
That such a book, opposed to all the tenets of medieval Christianity and common sense, should have been laboriously copied out in the ninth century, obviously by monks who understood some of what they read and transcribed, is truly surprising. The poem itself, and the character of its author, are something of a mystery too. But one thing is certain: it is a superb poem and it was written by a great poet. His name was Lucretius. He wrote it about sixty years before the birth of Jesus, and he called it The Nature of Things, i.e., The Nature of the Universe.