ime when, according to an unfortunate
tradition that has been very generally accepted, the Church dominated
human thinking so tyrannously as practically to preclude all notion of
original investigation in any line of thought, but especially in
matters relating to physical science. Most of the men whose lives are
sketched lived during the fifteenth, sixteenth, and first half of the
{5} seventeenth centuries. All of them were Catholic clergymen of high
standing, and none of them suffered anything like persecution for his
opinions; all remained faithful adherents of the Church through long
lives.

It is hoped that this volume, without being in any sense
controversial, may tend to throw light on many points that have been
the subject of controversy; and by showing how absolutely free these
great clergymen-scientists were to pursue their investigations in
science, it may serve to demonstrate how utterly unfounded is the
prejudice that would declare that the ecclesiastical authorities of
these particular centuries were united in their opposition to
scientific advance.

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 o