This introductory chapter provides a general framework for thinking about the relationship between wealth and power. It begins by situating the topic in the history of political thought, modern social science, and recent political philosophy, before putting forward an analytical framework. This has three elements: first, the idea of liberalism's public/private divide: a division between a power-wielding state from which wealth should be absent, and a market economy from which power should be absent; second, the two ways the division can be transgressed by the power of the wealthy: by the wealthy subverting the power of the state and by directly exercising power within the economy; and third, the four different approaches to responding to the transgression, either aiming to reassert the public/private divide or to move beyond it.