The modern idea of tolerance towards the beliefs and perceptions of others as an attitude that contributes to the common good emerged during the Enlightenment, after centuries of religious wars. Developed by great thinkers such as John Locke and Voltaire, it gradually gained ground and took root in Europe and North America.

However, with the resurgence of fanaticism and terrorism, religious tolerance is now being directly questioned by a frightened public opinion. Denis Lacorne examines the emergence and evolution of the modern idea of tolerance, inviting us to reflect on how we should respond to contemporary challenges.

He even gives his study a broad temporal horizon, examining even pre-modern aspects, such as the "tolerance" of the Ottomans and the Venetian Republic, reaching up to the ban on the burqa in France and the white supremacy movements in the USA in the 21st century.

The limits of tolerance raise critical questions: Should we impose limits on freedom of expression in the name of human dignity? Should we accept religious symbols in public spaces? Can we tolerate those who deny tolerance?

While he acknowledges that tolerance does not mean the abolition of all limits, the author defends it against recent attempts to bypass it. He argues that otherwise, the very existence of a pluralistic society is threatened. The book is a crucial contribution to the dialogue about the fundamental challenges facing democracy in the 21st century.