But there was one group of Greek thinkers whose general notions of natural operations correspond in a striking manner to the conclusions of the most recent science. These were the Epicureans. Democritus was in no way a modern experimental scientist, but he met the Eleatic metaphysics with another set of speculative considerations which happened to be nearer what is now regarded as the truth than theirs. He rejected the Eleatic decisions against the reality of space and motion on the ground that, since motion obviously took place, the void must be a reality, even if the metaphysician could not conceive it. He hit upon the notion that all things were composed of minute, indestructible particles (or atoms) of fixed kinds. Given motion and sufficient time, these might by fortuitous concourse make all possible combinations. And it was one of these combinations which we call the world as we find it. For the atoms of various shapes were inherently capable of making up all material things, even the soul of man and the gods themselves. There was no permanence anywhere; all was no more than the shifting accidental and fleeting combinations of the permanent atoms of which the cosmos was composed. This doctrine was accepted by the noble Epicurus and his school and is delivered to us in the immortal poem of Lucretius "On the Nature of Things". The Epicureans believed the gods to exist because, like Anselm and Descartes, they thought we had an innate idea of them. But the divine beings led a life of elegant ease and took no account of man; neither his supplications, nor his sweet-smelling sacrifices, nor his blasphemies, ever disturbed their calm. Moreover, the human soul was dissipated at death. So the Epicureans flattered themselves that they had delivered man from his two chief apprehensions, the fear of the gods and the fear of death. For, as Lucretius says, he who understands the real nature of things will see that both are the illusions of ignorance. Thus one school of Greek thinkers attained to a complete rejection of religious beliefs in the name of natural science. 9. INFLUENCE OF PLATO AND ARISTOTLE