There is no doubt that at times men have been the subject of persecution because of scientific opinions. In all of these cases, without exception, however--and this is particularly true of such men as Galileo, Giordano Bruno, and Michael Servetus--a little investigation of the personal character of the individuals involved in these persecutions will show the victims to have been of that especially irritating class of individuals who so constantly awaken opposition to whatever opinions they may hold by upholding them overstrenuously and inopportunely. They were the kind of men who could say nothing without, to some extent at least, arousing the resentment of those around them who still clung to older ideas. We all know this class of individual very well. {6} In these gentler modern times we may even bewail the fact that there is no such expeditious method of disposing of him as in the olden time. This is not a defence of what was done in their regard, but is a word of explanation that shows how human were the motives at work and how unecclesiastical the procedures, even though church institutions, Protestant and Catholic alike, were used by the offended parties to rid them of obnoxious argumentators. In this matter it must not be forgotten that persecution has been the very common associate of noteworthy advances in science, quite apart from any question of the relations between science and religion. There has scarcely been a single important advance in the history of applied science especially, that has not brought down upon the devoted head of the discoverer, for a time at least, the ill-will of his own generation. Take the case of medicine, for instance. Vesalius was persecuted, but not by the ecclesiastical authorities. The bitter opposition to him and to his work came from his colleagues in medicine, who thought that he was departing from the teaching of Galen, and considered that a cardinal medical heresy not to be forgiven. Harvey, the famous discoverer of the circulation of the blood, lost much of his lucrative medical practice after the publication of his discovery, because his medical contemporaries thought the notion of the heart pumping blood through the arteries to be so foolish that they refused to {7} admit that it could come from a man of common sense, much less from a scientific physician. Nor need it be thought that this spirit of opposition to novelty existed only in the sixteenth and seventeenth centuries. Almost in our own time Semmelweis, who first taught the necessity for extreme cleanliness in obstetrical work, met with so much opposition in the introduction of the precautions he considered necessary that he was finally driven insane. His methods reduced the mortality in the great lying-in hospitals of Europe from nearly ten per cent for such cases down to less than one per cent, thus saving many thousands of lives every year.