We can know the world. How then are we to understand it? Here again Epicurus found refuge in the old Ionian theory of Atoms and the Void, which is supposed to have originated with Democritus and Leucippus, a century before. But Epicurus seems to have worked out the Atomic Theory more in detail, as we have it expounded in Lucretius' magnificent poem. In particular it was possibly he who first combined the Atomic Theory with hylozoism; i. e. he conceived of the Atoms as possessing some rudimentary power of movement and therefore able to swerve slightly in their regular downward course. That explains how they have become infinitely tangled and mingled, how plants and animals are alive, and how men have Free Will. It also enables Epicurus to build up a world without the assistance of a god. He set man free, as Lucretius says, from the 'burden of Religion', though his doctrine of the 'blessed Being' which neither has pain nor gives pain, enables him to elude the dangerous accusation of atheism. He can leave people believing in all their traditional gods, including even, if so they wish, 'the bearded Zeus and the helmed Athena' which they see in dreams and in their 'common ideas', while at the same time having no fear of them. There remains the foolish fancy of the Cynics and Stoics that 'Aretê' is the only good. Of course, he answers, Aretê is good; but that is because it produces happy life, or blessedness or pleasure or whatever you call it. He used normally the word ἡδονή 'sweetness', and counted the Good as that which makes life sweet. He seems never to have entered into small disputes as to the difference between 'sweetness', or 'pleasure', and 'happiness' and 'well-being' (ἡδονή, εὐδαιμονία, εὐεστώ, κτλ.), though sometimes, instead of 'sweetness' he spoke of 'blessedness' (μακαριότης). Ultimately the dispute between him and the Stoics seems to resolve itself into a question whether the Good lies in πάσχειν or ποιεῖν, in Experience or in Action; and average human beings seem generally to think that the Good for a conscious being must be something of which he is conscious. Thus the great system is built, simple, intelligible, dogmatic, and--as such systems go--remarkably water-tight. It enables man to be unafraid, and it helps him to be happy. The strange thing is that, although on more than one point it seems to anticipate most surprisingly the discoveries of modern science, it was accepted in a spirit more religious than scientific. As we can see from Lucretius it was taken almost as a revelation, from one who had saved mankind; whose intellect had pierced beyond the 'flaming walls of Heaven' and brought back to man the gospel of an intelligible universe.[106:1]