defeat by Elam and a war sixteen centuries later which fully avenged it. This civilization flourished with brilliant splendor. Then it fell. In its northern seats it was overwhelmed by a wave of barbarism from among those half-savage peoples from whom you and I, my hearers, trace our descent. In the south and east it was destroyed later, but far more thoroughly, by invaders of an utterly different type. Both conquests were of great importance; but it was the northern conquest which in its ultimate effects was of by far the greatest importance. With the advent of the Dark Ages the movement of course ceased, and it did not begin anew for many centuries; while a thousand years passed before it was once more in full swing, so far as European civilization, so far as the world civilization of to-day, is concerned. During all those centuries the civilized world, in our acceptation of the term, was occupied, as its chief task, in slowly climbing back to the position from which it had fallen after the age of the Antonines. Of course a general statement like this must be accepted with qualifications. There is no hard and fast line between one age or period and another, and in no age is either progress or retrogression universal in all things. There were many points in which the Middle Ages, because of the simple fact that they were Christian, surpassed the brilliant pagan civilization of the past; and there are some points in which the civilization that succeeded them has sunk below the level of the ages which saw such mighty masterpieces of poetry, of architecture--especially cathedral architecture--and of serene spiritual and forceful lay leadership. But they were centuries of violence, rapine, and cruel injustice; and truth was so little heeded that the noble and daring spirits who sought it, especially in its scientific form, did so in deadly peril of the fagot and the halter. During this period there were several very important extra-European movements, one or two of which deeply affected Europe. Islam arose, and conquered far and wide, uniting fundamentally different races into a brotherhood of feeling which Christianity has never been able to rival, and at the time of the Crusades profoundly influencing European culture. It produced a civilization of its own, brilliant and here and there useful, but hopelessly limited when compared with the civilization of which we ourselves are the heirs. The great cultured peoples of southeastern and eastern Asia continued their checkered development totally unaffected by, and without knowledge of, any European influence.