These first advances enabled men to make others with greater rapidity. In proportion as they grew enlightened, they grew industrious. They ceased to fall asleep under the first tree, or in the first cave that afforded them shelter; they invented several kinds of implements of hard and sharp stones, which they used to dig up the earth, and to cut wood; they then made huts out of branches, and afterwards learnt to plaster them over with mud and clay. This was the epoch of a first revolution, which established and distinguished families, and introduced a kind of property, in itself the source of a thousand quarrels and conflicts. As, however, the strongest were probably the first to build themselves huts which they felt themselves able to defend, it may be concluded that the weak found it much easier and safer to imitate, than to attempt to dislodge them: and of those who were once provided with huts, none could have any inducement to appropriate that of his neighbour; not indeed so much because it did not belong to him, as because it could be of no use, and he could not make himself master of it without exposing himself to a desperate battle with the family which occupied it. The first expansions of the human heart were the effects of a novel situation, which united husbands and wives, fathers and children, under one roof. The habit of living together soon gave rise to the finest feelings known to humanity, conjugal love and paternal affection. Every family became a little society, the more united because liberty--and reciprocal attachment were the only bonds of its union. The sexes, whose manner of life had been hitherto the same, began now to adopt different ways of living. The women became more sedentary, and accustomed themselves to mind the hut and their children, while the men went abroad in search of their common subsistence. From living a softer life, both sexes also began to lose something of their strength and ferocity: but, if individuals became to some extent less able to encounter wild beasts separately, they found it, on the other hand, easier to assemble and resist in common. The simplicity and solitude of man's life in this new condition, the paucity of his wants, and the implements he had invented to satisfy them, left him a great deal of leisure, which he employed to furnish himself with many conveniences unknown to his fathers: and this was the first yoke he inadvertently imposed on himself, and the first source of the evils he prepared for his descendants. For, besides continuing thus to enervate both body and mind, these conveniences lost with use almost all their power to please, and even degenerated into real needs, till the want of them became far more disagreeable than the possession of them had been pleasant. Men would have been unhappy at the loss of them, though the possession did not make them happy.