BUT THE WORLD HAD UNDERGONE ANOTHER CHANGE WHICH WAS OF GREATER IMPORTANCE THAN EITHER THE POLITICAL OR THE INDUSTRIAL REVOLUTIONS. AFTER GENERATIONS OF OPPRESSION AND PERSECUTION, THE SCIENTIST HAD AT LAST GAINED LIBERTY OF ACTION AND HE WAS NOW TRYING TO DISCOVER THE FUNDAMENTAL LAWS WHICH GOVERN THE UNIVERSE THE Egyptians, the Babylonians, the Chaldeans, the Greeks and the Romans, had all contributed something to the first vague notions of science and scientific investigation. But the great migrations of the fourth century had destroyed the classical world of the Mediterranean, and the Christian Church, which was more interested in the life of the soul than in the life of the body, had regarded science as a manifestation of that human arrogance which wanted to pry into divine affairs which belonged to the realm of Almighty God, and which therefore was closely related to the seven deadly sins. The Renaissance to a certain but limited extent had broken through this wall of Mediaeval prejudices. The Reformation, however, which had overtaken the Renaissance in the early 16th century, had been hostile to the ideals of the "new civilisation," and once more the men of science were threatened with severe punishment, should they try to pass beyond the narrow limits of knowledge which had been laid down in Holy Writ. Our world is filled with the statues of great generals, atop of prancing horses, leading their cheering soldiers to glorious victory. Here and there, a modest slab of marble announces that a man of science has found his final resting place. A thousand years from now we shall probably do these things differently, and the children of that happy generation shall know of the splendid courage and the almost inconceivable devotion to duty of the men who were the pioneers of that abstract knowledge, which alone has made our modern world a practical possibility. Many of these scientific pioneers suffered poverty and contempt and humiliation. They lived in garrets and died in dungeons. They dared not print their names on the title-pages of their books and they dared not print their conclusions in the land of their birth, but smuggled the manuscripts to some secret printing shop in Amsterdam or Haarlem. They were exposed to the bitter enmity of the Church, both Protestant and Catholic, and were the subjects of endless sermons, inciting the parishioners to violence against the "heretics." Here and there they found an asylum. In Holland, where the spirit of tolerance was strongest, the authorities, while regarding these scientific investigations with little favour, yet refused to interfere with people's freedom of thought. It became a little asylum for intellectual liberty where French and English and German philosophers and mathematicians and physicians could go to enjoy a short spell of rest and get a breath of free air.