"Sad is it to think of what this great man might have given to the world had ecclesiasticism allowed the gift. He held the key to treasures which would have freed mankind from ages of error and misery. With his discoveries as a basis, with his method as a guide, what might not the world have gained! Nor was the wrong done to that age alone; it was done to this age also.... Thousands of precious lives shall be lost, tens of thousands shall suffer discomfort, privations, sickness, poverty, ignorance, for lack of discoveries and methods which, but for this mistaken dealing with Roger Bacon and his compeers, would now be blessing the earth." (White: "Warfare of Science.")
Centuries afterwards, for stating the same claim, namely, that much which was attributed to demons, resulted from natural causes, Cornelius Agrippa, Weyer, Flade, Loos, Bekker, and a multitude of other investigators and thinkers, suffered confiscation of property, loss of position, and even torture and death.
In the latter half of the sixteenth century, John Baptist Porta, who was the first to show how to reduce the metallic oxides and thus laid the foundation of several important industries, was summoned to Rome by Pope Paul II, and forbidden to continue his researches.
Both in Protestant and Catholic countries instruction in chemistry and physics was discouraged by Church authorities, and in England the theologians strenuously opposed the Royal Society and the Association for the Advancement of Science.
Francis Bacon and Boyle were denounced by the clergy, and Lavoisier was sent to the scaffold by the Parisian mob. Priestley had his home, his library, instruments, and papers containing the results of long years of scientific research burned by a Birmingham mob that had been instigated by Anglican clergymen. He was driven into exile, and the mob would have murdered him if they could have laid their hands upon him.
Yet, in spite of the opposition of the clergy, an opposition of such force that one may well wonder how these tender embryonic sciences could have withstood the terrific ecclesiastical onslaughts, the truths of chemistry and physics continued to diffuse themselves among the intelligent observers. The value to humanity of these two sciences is now established as inestimable.