However much the renewal of classical learning in the fourteenth, fifteenth, and sixteenth centuries may have furthered the development of letters and of art, it had anything but a favourable influence on the progress of science. The interest awakened in the literature of Greece and Rome was shown in admiration not only for the works of poets, historians, and orators, but also for those of physicians, anatomists, and astronomers. In consequence scientific investigation was almost wholly restricted to the study of the writings of authors like Aristotle, Hippocrates, Ptolemy, and Galen, and it became the highest ambition to explain and comment upon their teachings, almost an impiety to question them. Independent inquiry, the direct appeal to nature, were thus discouraged, and indeed looked upon with the utmost distrust if their results ran counter to what was found in the works of Aristotle or Galen. This spell of ancient authority was broken by the anatomists of the sixteenth century, who determined at all costs to examine the human body for themselves, and to be guided by what their own observations revealed to them; and it was finally overcome by the independent genius of two men working in very different scientific spheres, Galileo and Harvey. These illustrious observers were contemporaries during the greater part of their lives, and were some years together at the famous University of Padua. Galileo and Harvey refused to be bound by the teachings of Aristotle and Galen, and appealed from these authorities to the actual facts of nature which any man could observe for himself. Their scientific work is therefore of interest, not only for the innate value of the discoveries they made, but also because it shows them as pioneers in that independent spirit of scientific inquiry to which the great advance in natural knowledge since their time is so largely due. Harvey’s work, by which his name has been made immortal, strikingly illustrates this. He was the first to show the nature of the movements of the heart, and how the blood moved in the body. He did so by putting on one side authority, and directly appealing to observation and experiment. The completeness of the success with which this independent line was taken, as exemplified in his treatise “On the Movement of the Heart and Blood,” is such as to excite the admiration of every modern physiologist. “C’est un chef-d’œuvre,” says a distinguished French physiologist, Flourens, “ce petit livre de cent pages est le plus beau livre de la physiologie.”[1] [1] Flourens, Histoire de la Découvert de la Circulation du Sang, 1854.