It is of the nature of desire not to be satisfied, and most men live only for the gratification of it.
AristotleFor suppose that every tool we had could perform its task, either at our bidding or itself perceiving the need, and if-like the statues made by Dรฆdalus or the tripods of Hephรฆstus, of which the poet says that "self-moved they enter the assembly of the gods" - shuttles in a loom could fly to and fro and a plectrum play a lyre all self-moved, then master-craftsmen would have no need of servants nor masters of slaves.
Aristotle