In a single book, which deals with a vast mass of facts and with records extending over a period of nearly three centuries, it is impossible to do more than indicate in very general terms the nature of the different currents and variations of the fundamental Zionist idea. It would be a tedious, and indeed an impossible task, to attempt a full examination of the mass of material accessible in the form of literature and personal reminiscences. It would require several volumes. While, then, the magnitude of the subject prevents me from attempting to present my case with absolute completeness within the limits of this work, nevertheless it is sufficiently important to justify the endeavour to summarize its most prominent features. I shall indeed be thankful if my work succeeds in disposing of the most important points I touch upon. This book has not been written with a view to Zionist propaganda among the masses. But the propagandist may be able to make use of some of the material and reproduce it in popular articles and pamphlets. The book may also prove of interest to those who have the will and the patience to study the problem of Zionism more deeply. Students with the inclination to examine more closely into the subject will find the necessary indications in the text, as well as in the Appendices and the Indexes. I have spared no pains in my endeavour to obtain the best sources of information and to secure accuracy, and have also made every effort to consult all the literature bearing upon the subject, making liberal use of all material accessible to me. I have given the authorities for my statements wherever possible, so that those who may be desirous of investigating the subject more fully may have an opportunity of judging for themselves as to the credibility of the evidence upon which my conclusions are based. It is almost certain, however, that small mistakes have crept in occasionally, and I shall be grateful for any corrections which may at any time be indicated to me by readers. This will be particularly the case with regard to the records dealing with the workers in the various countries, the movement at the Universities, and so forth. It was in some instances difficult to select names, and I have been under the necessity of omitting some just as important as those which I have recorded. And in connection with this part of my work I had very little literature, and it is quite possible that my memory has failed me in respect of the order and details of certain facts and events. But I hope that such errors can be easily corrected.