Abstract
It would be unproblematically correct to say "the laws of Pennsylvania have it that a person is eligible to vote at age eighteen." But whether someone is actually mature enough to exercise his electoral franchise appropriately will very much depend on the individual. In setting the voting age by fiat, Society leaps in where Nature fears to tread. Many quantities that figure importantly in shaping our conduct of affairs are not specified by nature but are artifacts of human contrivance. At what age, for example, is a person old enough to marry, drink alcoholic beverages responsibly, handle fireworks safely, manage his own property, enter into contracts, see a violent movie, serve on a jury, or hold a public office? These are not quantities writ large in nature's impersonal scheme of things but matters of social decision made for reasons of public polity and administrative convenience. They are legislated quantities.
