It is a far cry from the great Zarathustra or Zoroaster, who formed the subject of our last lecture in this series, to the three great personalities who provide the subject matter of our lecture to-day, and the gulf of time which, in our imagination, we are called upon to span is wide indeed. It is a gulf which stretches from a time thousands of years ago, long before our Christian Era. A time which we can only understand by attributing to the human beings existing then a mental outlook utterly foreign to our own. From this distant standpoint of time, we pass to the 16th and 17th centuries of our own era, to the time when that spirit was first kindled which, ever since, has been the source and inspiration of all vital and progressive culture from then to the present day. As we shall see, this spirit, which burnt so fiercely in the 16th and 17th centuries in individuals such as Galileo and Giordano Bruno, found a fresh medium in a personality so near our own times as that of Goethe.