A man loses his son to suicide then the local religious fanatics claim he murdered his son because his son was about to change his religion to theirs and then tortured him to death, no this is not a country in the modern Middle East this is pre-Revolutionary France. A Treatise on Tolerance and Other Writings by the French Enlightenment thinker Voltaire who looks to exonerate a man of accused of killing his son and the religious fanaticism that inspired the injustice.

In reaction to the 1762 miscarriage of justice relating to the suicide of Marc-Antione Calas that ultimately led to the execution of his father Jean by religious fanatics “out for justice”. The whole affair caused a scandal resulting in the philosopher Voltaire became the champion for justice for the surviving Calas family, which brought about this Treatise. Voltaire describes the fatal events of the night of Marc-Antione’s death with evidence that he was for a time had studied how to take his own life, that the timing of his death around the celebration of the anniversary of a well-planned massacre of Huguenots—French Protestants—in Toulouse during the Wars of Religion that led to conspiratorial stories about Jean killing his son because he wanted to convert to Catholicism while ignoring that he had been fine with a younger son already doing that, and the total lack of justice in the entire process. The Treatise of Tolerance then becomes a clarion call for religious toleration while also attacking religious fanaticism—Voltaire specifically points to French Jesuits of his time with able arguments—and the superstition surrounding religion that leads to situations like in Toulouse. Voltaire also writes excellent endnotes that are very informative, though the decision of the publishers of this edition to put those Notes at the end of the book and not at the end of the chapters was a bit annoying. This is one of the most important works of philosophy and religion from the Enlightenment era for those that support the freedom of religion and are opponents to religious fanaticism.

A Treatise on Tolerance and Other Writings is a very well written defense of a wrongly executed man while arguing for religious tolerance and against religious fanaticism by the Enlightenment’s best known philosopher, Voltaire. ( )