It is often said that mankind needs a faith if the world is to be improved. In fact, unless the faith is vigilantly and regularly checked by a sense of man's fallibility, it is likely to make the world worse. From Torquemada to Robespierre and Hitler the men who have made mankind suffer the most have been inspired to do so have been inspired to do so by a strong faith; so strong that it led them to think their crimes were acts of virtue necessary to help them achieve their aim, which was to build some sort of an ideal kingdom on earth.