The Importance of Scientific Experiments
  The rise of modern science may perhaps be considered to date as far back as the time of Roger Bacon, the wonderful monk and philosopher of Oxford, who lived between the years 1214 and 1292. He was probably the first, in the mid- tide ages to assert that we must learn science by observing and experimenting on the things around us, and he himself made many remarkable discoveries. Galileo, however, who lived more than 800 years later (1564 to 1642), was the greatest of several great men, who in Italy, France, Germany, or Eng- land, began by degrees to show how many important truths could be discovered by well-directed observation. Before the time of Galileo, learned men believed that large bodies fall more rapidly towards the earth than small ones, because Aristotle said so. But Galileo, going to the top of the Leaning Tower of Pisa, let fall two unequal stones, and proved to some friends, whom he had brought there to see his experiment, that Aristotle was in error. It is Galileo¡¯s spirit of going direct to Nature, and verifying our opinions and theories by experiment, that. has led to all the great discoveries of modern science.
     From Logic by William Stanley Jevons