Throughout this book I have tried to point out why interest, especially as it has been used by people such as Hume, Smith, Tocqueville, and Weber, is still a very useful concept. One reason why the concept of interest imparts a distinct dynamic to the analysis is that it is mainly interest which makes people takes action. It supplies the force that makes people get up at dawn and work very hard throughout the day. Combined with interests of others, it is a force that can move mountains and create new societies.