I purpose to present an outline of the great sacred struggle for the liberty of science — a struggle which has lasted for so many centuries, and which yet continues. A hard contest it has been a war waged longer with battles fiercer with sieges more persistent with strategy more shrewd than in any of the comparatively transient warfare of Caesar or Napoleon or Moltke. ¶ I shall ask you to go with me through some of the most protracted sieges and over some of the hardest fought battle fields of this war We will look well at the combatants we will listen to the battle cries we will note the strategy of leaders the cut and thrust of champions the weight of missiles the temper of weapons we will look also at the truces and treaties and note the delusive impotency of all compromises in which the warriors for scientific truth have consented to receive direction or bias from the best of men uninspired by the scientific spirit, or unfamiliar with scientific methods.My thesis, which, by an historical study of this warfare, I expect to develop, is the following: In all modern history, interference with science in the supposed interest of religion, no matter how conscientious such interference may have been, has resulted in the direst evils loth to religion and to science — and invariably. And, on the other hand, all untrammeled scientific investigation no matter how dangerous to religion some of its stages may have seemed, for the time, to be, has invariably resulted in the highest good of religion and of science. I say invariably. I mean exactly that. It is a rule to which history shows not one exception.