Huts they made then, and fire, and skins for clothing, And a woman yielded to one man in wedlock...
...Common, to see the offspring they had made;
The human race began to mellow then.
Because of fire their shivering forms no longer
Could bear the cold beneath the covering sky.

On the Nature of Things, trans. Anthony M. Esolen (1995), Book 5, lines 1008–13