This book begins with a discussion of John Locke's "Letter of Toleration" and John Stuart Mill's "On Liberty". Drawing on the theories of Locke and Mill, it analyzes the concept of toleration and explores its relationship to other central concepts in political thought, notably liberty and equality. It then attempts to respond to some important problems concerning toleration: Why is toleration thought to be good? When ought it to be limited and why? Should we tolerate the intolerable?