Jewish mysticism represents the totality of the attempts to interpret in terms of mystical conceptions the meaning of rabbinical Judaism as it has crystallized in the time of the Second Temple and later. Such a development, of course, could take place only after this process of crystallization had attained a certain degree of fixity. This holds good for both the type of legal Judaism which Philo of Alexandria tried to interpret, as well as for the more developed type of Talmudic Judaism which served as a frame for the spiritual efforts of the Medieval Kabbalists. It is not my purpose to discuss here the historical problems of the development of Jewish mysticism, and especially of Kabbalism; I have done so in other places, especially in my book Major Trends in Jewish Mysticism. On the other hand, the subject with which I propose to deal here occupies a central place in Jewish mysticism. In a religious system that is based on Divine Revelation and the acceptance of Holy Scriptures which determine its tenets, the questions connected with the essential nature of such revelation in Scripture are obviously vital ones. Moreover, in a time of crisis—andmysticism as a historical phenomenon is a child of times of crises—such questions are especially pressing. Mystics are people who, through their own experience and speculation on such experience, detect new layers of meaning in their traditional religion. If this kind of experience and speculation does not lead them to break away from the traditional institutional framework of their religion, then the first question bound to come up is how to find their own experience reflected or anticipated in their sacred texts; also how to reconcile their vision of things with that accepted by their own tradition. It is, of course, a truism that allegorical interpretation makes its appearance spontaneously whenever new ideas clash with those of a holy book, seemingly standing in contradiction to them and requiring some process of reconciliation. What is true of allegorical interpretation applies even more so to mystical interpretation in a more precise sense.