How important is equality? The notion of equality is of tremendous practical importance in discussions of economic policy and also of fundamental theoretical importance in ethics. Additionally, the concept of equality lies at the heart of moral theories. To determine what to equalize, one needs to understand what one wants equality for. Determining what to equalize and determining why the pursuit of equality is morally justified are inseparable inquiries. There are also serious problems when the pursuit of equality comes into conflict with the constraints imposed by rights or with other objectives such as welfare or liberty. In order to analyze these controversial topics, this chapter focuses on the topics of why we should equalize, what should we equalize, and how important is equality exactly.