FRANCE IN THE SEVENTEENTH CENTURY 419 THE SCIENCES, LITERATURE, AND THE ARTS Progress of the Sciences—In all the countries of Europe, from the sixteenth century there have been men who were occupied in studying science. Some (Bacon, Descartes, Newton) were gentlemen, or rich bourgeois, who were able to devote their time to dis- interested study. The larger number were professors in some university, or the pensioners of some prince. Almost all were laymen; since the end of the Mid- dle Ages the clergy have produced few distinguished savants. A revolution in the manner of comprehending sci- ence took place in the sixteenth century. In the Middle Ages science was sought for in the ancient books; to be a savant, meant to know what the mas- ters had written: Galen in medicine, Aristotle in philosophy, Ptolemy in astronomy. From the time of the Renaissance people became gradually accustomed to the idea that the only way to know things was to look at them; science was constituted through observa- tion of phenomena. The savants were less occupied with learning what had been said before them than with studying what they could see for themselves. They began to experiment, to weigh, to dissect, to collect. There were invented in Holland two kinds of instruments, which greatly increased the field of observation; the microscope (1590) showed objects too small, the telescope (1609) objects too far away to be seen with the naked eye.