“When,” he writes, “I returned from Palestine in 1912, and my _Summa Summarum_ aroused violent anger in various quarters, I wrote an explanatory note by way of supplement to that essay; and I should like to remind my readers on this occasion of some of the things that I said then, because they seem to me relevant at the present time. ‘There must be,’ I wrote, ‘some natural connection of cause and effect between an object and the means by which its attainment is sought: we must be able to show how this object can be attained by these means. So long as that connection does not exist, so long as we cannot attempt to justify our choice of means except by such vague phrases as ”Perhaps ... you never can tell ... times change ...”—we may speak of cherished hopes and an ideal for the distant future, but we cannot speak of a _practical_ object which can serve as a basis for a systematic plan of work. For every systematic plan of work must necessarily be based on a clear conception (whether intellectual or imaginative) of the chain of cause and effect which connects the various activities one with another, and all of them together with the object.... No doubt, we cannot foretell the future; no doubt it is possible that unforeseen things may happen and may change the face of reality. But a possibility of that kind cannot be made the basis of a systematic plan of work, and we are dealing no longer with an objective of immediate activity, but with a vision of the future.’ “About two years after these words were written and published the world-war began, and led to those results which we know: ‘unforeseen things happened and changed the face of reality.’ Our own life, too, was caught in the maelstrom of world-happenings; and the face of our own reality, too, was changed as a consequence. Much might be said, and has already been said, about the character of these changes, about their good and their bad side, about their significance both for the Diaspora and for Palestine. I cannot now deal with this subject fully, and I wish for my part only to say a word or two on one of the principal features of the changed situation—I mean the widening of the horizon of our work in Palestine through the famous Declaration of the British Government, which has recently been confirmed by the Supreme Council, and thus has ceased to be merely the promise of a single Government and has become an international obligation. This Declaration has provided a new ‘basis for a systematic plan of work,’ and has set up ‘an objective of immediate activity’—activity on a large scale, such as has been hitherto only a theme for the anticipations of orators and essayists, with no real basis in the present. But at the same time the Declaration has winged anew the imagination of those who were already accustomed to build castles in the air, without regard to the realities of this earthly life. That is, I fancy, one of the reasons why there is still a demand for this book,