Aiming, as the Epicureans did, at explaining the origin of men and animals in a purely natural manner, they likewise tried to form an idea, equally according to nature, of the original state and historical development of the human race. In this attempt they ignored all legendary notions, and, notwithstanding their leaning towards materialism, they on the whole advocated perfectly sound views. The men of early times, so thought Lucretius, were stronger and more powerful than the men of to-day. Rude and ignorant as beasts, they lived in the woods in a perpetual state of warfare with the wild animals, without justice or society. [1208] The first and most important step in a social direction was the discovery of fire, the learning to build huts, and to clothe themselves in skins; then began marriage and domestic life, [1209] and speech, originally not a matter of convention, but, like the noises of animals, the natural expression of thoughts and feelings, was developed. [1210] The older the human race grew, the more they learned of the arts and skill which minister to the preservation and enjoyment of life. These arts were first learnt by experience, under the pressure of nature, or the compulsion of want. What had thus been discovered was completed by reflection, the more gifted preceding the rest as teachers. [1211] In exactly the same way civil society was developed. Individuals built strongholds, and made themselves rulers. In time the power of kings aroused envy, and they were massacred. To crush the anarchy which then arose, magistrates were chosen, and order established by penal laws. [1212] It will subsequently be seen that Epicurus explained religion in the same way by natural growth. [(2) The soul.]