[369] with each other, from 100 before to 400 after Christ, the so-called religious period of the ancient world in which the only question was the salvation of the individual soul^a out of a demonically controlled world. Or we can compare it with the still earlier period, from 600 to 100, especially with relation to Greece, where the question was to find the immovable in the changes of the movable. Now I would like to go into this, and I have an appointment with the History Department to speak about this in one of the next weeks. In any case, this is based on one belief I have, that philosophical and artistic expressions of the period are not arbitrary, and are not dependent on individual creativity alone, but that they are produced by an emergency, i.e. a real problem, a problem which is not an artificial logical problem only--the logic expresses it too--but which is a problem going down to the existence of human beings in a special period. When I still was more daring than I am today, I used to say: perhaps the period which starts around 1900, OUR period, might be called, in a few hundred years, the period in which the

central emergency was our historical existence^b. Sometimes I still believe I was right. But since no one can say what the underlying problem of one's own period is, this is more an anticipation and a guess than a statement which I could make with the same conviction in which I can make (and prove, in all special things) the other statements about the other periods. Now if I say our period is the period of man controlling nature and society in the power of reason, or the logos^c, then I can immediately make a short intermission in the process of my thought, namely that this period is not unbroken, and the pictures I gave you have shown this quality I hope very closely. In the late Renaissance, a reaction against the naturalistic self-interpretation