The Great Heresies

Belloc's starting point is that Christian faith is under attack, and cites six different heresies, some of which are historical, and some a real danger today.

Heresy has a very specifying meaning here for Belloc. It's when you take a basic idea, retain it, but twist one aspect of it. So all these attacks on Christianity started with Christianity itself, which is why the threats and attacks are so dangerous, but it is a perversion of the original idea.

Included as heretical attacks on Christianity are both Islam and Protestantism.

A heresy is when you take a basic idea, retain it, but twist an aspect of it. There are five heresies covered in this book which includes Islam and Protestantism.

"Mohammed insisted upon a whole group of ideas which were peculiar to the Catholic Church... the very foundation of his teaching was that prime Catholic doctrine, the unity and omnipotence of God," writes Belloc. And it is this proximity, this dangerous theft of Christian ideas, that marks Islam as so dangerous.

This book was written almost a hundred years ago when Islam was in a state of abeyance, but it clearly warns that at any time there could be a resurgence of Islam, which will mark danger for the west and for Christianity.