Both Self-restraint and Unrestraint are a matter of extremes as compared with the character of the mass of mankind; the restrained man shows more and the unrestrained man less steadfastness than most men are capable of.
One citizen differs from another, but the salvation of the community is the common business of them all. This community is the constitution; the virtue of the citizen must therefore be relative to the constitution of which he is a member.
Any change of government which has to be introduced should be one which men, starting from their existing constitutions, will be both willing and able to adopt, since there is quite as much trouble in the reformation of an old constitution as in the establishment of a new one, just as to unlearn is as hard as to learn.
For 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 Dædalus or the tripods of Hephæstus, 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.