Christian scholars often say that Sufi theories are close to those of Christianity. Many Moslems maintain that they are essentially derived from Islam. The resemblance of many Sufi ideas to those of several religious and esoteric systems are sometimes taken as evidence of derivation. The Islamic interpretation is that religion is of one origin, differences being due to local or historical causes.

The Elephant in the Dark (ed. Octagon Press Ltd, 1974) - ISBN: 9780900860362