It might strike the average reader as exceedingly odd that any attempt should be made at writing a book on Jewish mysticism. The prevailing opinion-among theologians as well as in the mind of the ordinary man seems to be that Judaism and mysticism stand at the opposite poles of thought, and that, therefore, such a phrase as Jewish mysticism is a glaring and indefensible contradiction in terms. It is to be hoped that the contents of this little book will show the utter falsity of this view. This is a reprint of the original text. Its clarity has been enhanced but there are some original marks from the reader of the text. These marks do not affect the legibility of the text.