After a long period of decline, the city of Rome fell to barbarians in A.D. 476. This lecture visits that time and immediately after to see what scientific and philosophical thought was saved from the wreck of classical civilization—how, why, and by whom. The rise of Christianity is key at this point. We address why the Middle Ages inherited only what it did from the Classical world. This topic asserts consideration of the cultural factors on which the continuance of science and technology depends.