One of the principal causes of unbelief in the modern world is the plurality of religions which appear mutually contradictory. So long as the Europeans were convinced of their own racial superiority they had no reason to doubt that Christianity was the only true Faith. The notion that they were the crown of the `evolutionary process' made it easy to assume that all other religions were no more than naive attempts to answer perennial questions. It was when this racial self-confidence declined doubts crept in.