BOOK REVIEW - John Locke "A Letter Concerning Toleration" (1689) By Nayeli L. Riano Toleration is a concept that we consider commonsensical today. Religious toleration, moreover, is a fundamental concept that many of us would consider essential for the human right to worship freely. However, this was not always the reality. What we recognise as a general custom of humanity has evolved from years of debate over what it means to be tolerant and toward whom. Also, we as a society still have a long way to go in this quest for tolerance, yet, though it may still be imperfect, toleration is a concept that has been broadened largely through thinkers in the liberal tradition. Locke’s A Letter Concerning Toleration is a difficult work to critique because it is the product of his theological and political thoughts. Locke’s ideas on toleration were influential in developing liberal thought and importing fundamental liberal principles into the intellectual debate. On the one hand, the concept of tolerance described raised controversial questions and challenged liberal reasoning. On the other hand, it has restored tolerance as the basic principle for a liberal society.