In this new edition of a classic work, the great Catholic apologist and historian Hilaire Belloc examines the five most destructive heretical movements in Christianity: Arianism, Mohammedanism (Islam), Albigensianism, Protestantism, and Modernism. Belloc describes how these movements began, how they spread, and how they have continued to influence the world. He accurately predicts the re- emergence of militant Islam and its violent aggression against Western civilization.

When we hear the word "heresies", we tend to think of distant centuries filled with religious quarrels that seemed important at the time but are no longer relevant. Belloc shows that the heresies of olden times are still with us, sometimes under different names and guises, and that they still shape our world.

"We live with the aftereffects of twenty centuries of heresies. If this book speaks to us as though it were written yesterday, it is because heresy is a perennial problem. 'All men by nature desire to know', said Aristotle, but many men are incapable of knowing well or of thinking clearly. The result is religious error. To deal with it, we must learn its origin and history. There seldom has been a better teacher than Hilaire Belloc."
— Karl Keating, from the Foreword; Author, Catholicism and Fundamentalism

The Great Heresies is a masterpiece of intellectual history which takes us on a journey across the landscape of the centuries. With the inimitable Belloc as our guide we follow the path of the Church Militant as she passes, sure-footed with the grace of orthodoxy, through the quagmire of errors which characterize the prideful wanderings of the human mind and heart."
— Joseph Pearce, Author, Catholic Literary Giants