Greece lost her liberty at Chaeronea, and with liberty her fairest hopes of continued intellectual development. Nevertheless, during a great part of a thousand years the Greek and Semitic school of Alexandria cultivated the sciences with diligence and success. We must say nothing here about the geometry, astronomy, optics, or geography there taught, but merely note that Herophilus and Erasistratus, unimpeded by that repugnance to mutilation of the human body which had been insurmountable at Athens, made notable advances in anatomy and physiology. From this time a fair knowledge of the bodily structure of man, decidedly superior to that which Aristotle had possessed, was at the command of every educated biologist. The genius of Rome applied itself to purposes remote from science. The example of Alexandria had its influence, however, upon some inhabitants of the Roman Empire. Galen of Pergamum in Asia Minor prosecuted the study of human anatomy. His knowledge of the parts which can be investigated by simple dissection was extensive, but he was unpractised in experimental physiology. Hence his teaching, though full with respect to the skeleton, the chief viscera, and the parts of the brain, was faulty with respect to the flow of the blood through the heart and body. Ages after his death the immense reputation of Galen, like that of Aristotle, was used with great effect to discredit more searching inquiries. Under the Roman Empire also flourished Dioscorides, who wrote on the plants used in medicine, and the elder Pliny, who compiled a vast, but wholly uncritical, encyclopædia of natural history. We see from these facts how ancient nations, inhabiting the Mediterranean basin and largely guided by Greek intelligence, had not only striven to systematise that knowledge of plants and animals which every energetic and observant race is sure to possess, but had with still more determination laboured to create a science of human anatomy which should be serviceable to the art of medicine. The effort was renewed time after time during five or six centuries, but was at last crushed under the conquests of a long succession of foreign powers—Macedonians, Romans, Mohammedan Arabs, and northern barbarians—each more hostile to knowledge than its predecessors. Extinction of Scientific Inquiry. The decline and fall of the Roman Empire brought with it the temporary extinction of civilisation in a great part of Western Europe. Science was during some centuries taught, if taught at all, out of little manuals compiled from ancient authors. Geometry and astronomy were supplanted by astrology and magic; medicine was rarely practised except by Jews and the inmates of religious houses. Literature and the fine arts died out almost everywhere.