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.

In another chapter I have told you how Roger Bacon, the great genius of the thirteenth century, was prevented for years from writing a single word, lest he get into new troubles with the authorities of the church. And five hundred years later, the contributors to the great philosophic ``Encyclopaedia'' were under the constant supervision of the French gendarmerie. Half a century afterwards, Darwin, who dared to question the story of the creation of man, as revealed in the Bible, was denounced from every pulpit as an enemy of the human race.

Even to-day, the persecution of those who venture into the unknown realm of science has not entirely come to an end. And while I am writing this Mr. Bryan is addressing a vast multitude on the ``Menace of Darwinism,'' warning his hearers against the errors of the great English naturalist.

All this, however, is a mere detail. The work that has to be done invariably gets done, and the ultimate profit of the discoveries and the inventions goes to the mass of those same people who have always decried the man of vision as an unpractical idealist.

The seventeenth century had still preferred to investigate the far off heavens and to study the position of our planet in relation to the solar system. Even so, the Church had disapproved of this unseemly curiosity, and Copernicus who first of all had proved that the sun was the centre of the universe, did not publish his work until the day of his death. Galileo spent the greater part of his life under the supervision of the clerical authorities, but he continued to use his telescope and provided Isaac Newton with a mass of practical observations, which greatly helped the English mathematician when he dis- covered the existence of that interesting habit of falling objects which came to be known as the Law of Gravitation.

That, for the moment at least, exhausted the interest in the Heavens, and man began to study the earth. The invention of a workable microscope, (a strange and clumsy little thing,) by Anthony van Leeuwenhoek during the last half of the 17th century, gave man a chance to study the ``microscopic'' creatures who are responsible for so many of his ailments. It laid the foundations of the science of ``bacteriology'' which in the last forty years has delivered the world from a great number of diseases by discovering the tiny organisms which cause the complaint. It also allowed the geologists to make a more careful study of different rocks and of the fossils (the petrified prehistoric plants) which they found deep below the surface of the earth. These investigations convinced them that the earth must be a great deal older than was stated in the book of Genesis and in the year 1830, Sir Charles Lyell published his ``Principles of Geology'' which denied the story of creation as related in the Bible and gave a far more wonderful description of slow growth and gradual development.

At the same time, the Marquis de Laplace was working on a new theory of creation, which made the earth a little blotch in the nebulous sea out of which the planetary system had been formed and Bunsen and Kirchhoff, by the use of the spectroscope, were investigating the chemical composition of the stars and of our good neighbour, the sun, whose curious spots had first been noticed by Galileo.

Meanwhile after a most bitter and relentless warfare with the clerical authorities of Catholic and Protestant lands, the anatomists and physiologists had at last obtained permission to dissect bodies and to substitute a positive knowledge of our organs and their habits for the guesswork of the mediaeval quack.

Within a single generation (between 1810 and 1840) more progress was made in every branch of science than in all the hundreds of thousands of years that had passed since man first looked at the stars and wondered why they were there. It must have been a very sad age for the people who had been educated under the old system. And we can understand their feeling of hatred for such men as Lamarck and Darwin, who did not exactly tell them that they were ``descended from monkeys,'' (an accusation which our grandfathers seemed to regard as a personal insult,) but who suggested that the proud human race had evolved from a long series of ancestors who could trace the family-tree back to the little jelly-fishes who were the first inhabitants of our planet.

The dignified world of the well-to-do middle class, which dominated the nineteenth century, was willing to make use of the gas or the electric light, of all the many practical applications of the great scientific discoveries, but the mere investigator, the man of the ``scientific theory'' without whom no progress would be possible, continued to be distrusted until very recently. Then, at last, his services were recognised. Today the rich people who in past ages donated their wealth for the building of a cathedral, construct vast laboratories where silent men do battle upon the hidden enemies of mankind and often sacrifice their lives that coming generations may enjoy greater happiness and health.

Indeed it has come to pass that many of the ills of this world, which our ancestors regarded as inevitable ``acts of God,'' have been exposed as manifestations of our own ignorance and neglect. Every child nowadays knows that he can keep from getting typhoid fever by a little care in the choice of his drinking water. But it took years and years of hard work before the doctors could convince the people of this fact. Few of us now fear the dentist chair. A study of the microbes that live in our mouth has made it possible to keep our teeth from decay. Must perchance a tooth be pulled, then we take a sniff of gas, and go our way rejoicing. When the newspapers of the year 1846 brought the story of the ``painless operation'' which had been performed in America with the help of ether, the good people of Europe shook their heads. To them it seemed against the will of God that man should escape the pain which was the share of all mortals, and it took a long time before the practice of taking ether and chloroform for operations became general.

But the battle of progress had been won. The breach in the old walls of prejudice was growing larger and larger, and as time went by, the ancient stones of ignorance came crumbling down. The eager crusaders of a new and happier social order rushed forward. Suddenly they found themselves facing a new obstacle. Out of the ruins of a long-gone past, another citadel of reaction had been erected, and millions of men had to give their lives before this last bulwark was destroyed.