If I thought sermonizing would wear out Willard for my questions, I was dead wrong.
In the tenth book of the Republic we find the curious argument that the soul does not perish like the body, because its characteristic evil, sin or wickedness does not kill it as the diseases of the body wear out the bodily life.
It is not brittle like porcelain and cast iron, not poisonous like lead-glazed earthenware and untinned copper, needs no enamel to chip off, does not rust and wear out like cheap tin-plate, and weighs but a fraction of other substances.
Hence objects which need much machining are made rich in graphite, so that gressively from the state of graphite to that of cementite as we pass they may be cut easily, and those of the latter class rich in from specimen to specimen, may, with the foregoing picture of a cementite so that they may not wear out.
On the other hand, the lower position there assigned to women and the very considerable amount of hard work exacted from them, may cause them to wear out earlier than under higher conditions, though not to the extent implied in the statistics.