Constitutions are various: there must thus be various kinds of citizens; more especially, there must be various kinds of citizens who are subjects. In one variety of constitution will be necessary that mechanics and labourers should be citizens: in other varieties it will be impossible. If will be impossible, for example where there is a constitution of the type termed aristocratic, with offices distributed on the basis of worth and excellence: for a man who lives ; the life of a mechanic or labourer cannot pursut the things which to excellence.