18. They have not learned, I will be told, to make clothing, seats, ships, and ploughs, nor, in fine, the other furniture which family life requires. These are not the gifts of science, but the suggestions of most pressing necessity; nor did the arts descend with men's souls from the inmost heavens, but here on earth have they all been painfully sought out and brought to light, ^[3527] and gradually acquired in process of time by careful thought. But if the soul ^[3528] had in itself the knowledge which it is fitting that a race should have indeed which is divine and immortal, all men would from the first know everything; nor would there be an age unacquainted with any art, or not furnished with practical knowledge. But now a life of want and in need of many things, noticing some things happen accidentally to its advantage, while it imitates, experiments, and tries, while it fails, remoulds, changes, from continual failure has procured for itself ^[3529] and wrought out some slight acquaintance with the arts, and brought to one issue the advances of many ages.