Locke argues that man would use the goods of his labour to barter with others and appropriate different goods. No man was allowed to appropriate more than he could barter or use. Some goods were worth more than others; for example, maybe one year there is a shortage of corn but an abundance of mutton, obviously the corn has more value and the person who grew the corn therefore more wealth. Locke claims that eventually man agreed to allow a certain metal or jewel common to all, that was not perishable, serve as money to appropriate goods. Locke states "and as different degrees of industry were apt to give men possessions in different proportions, so this invention of money gave them the opportunity to continue and enlarge them" (Locke, 29).
The nineteenth century philosopher John Stuart Mill believed that for man to be truly free the rights and liberties of the individual must be guaranteed. Mill was concerned with what he called "Civil or Social Liberty: the nature and limits of the power which can be legitimately exercised over the individual" (Mill 13). Mill argues that there are two distinct parts of a person's life; that part of a person's life that "concerns himself only," and that part "which concerns others" (74).