It has been contended by a large and intelligent class of writers, and those who most pride themselves on scientific methods and the infallibility of scientific inductions, that mind is only the product of organization and ceases to have any activity or even existence when the organs through which it usually manifests itself have perished. The general consensus of mankind is a sharp protest against this conclusion--but the experimental proofs have, to many, seemed in favor of this scientific denial;--the healthy brain in general exhibits a healthy mental activity, the diseased or imperfect brain shows impaired mental action, and the disorganized brain simply exhibits no mental activity nor any evidence whatever of the existence of mind. Nevertheless, it is a lame argument; it is simply an attempt to prove a negative. The healthy rose emits an agreeable odor which our senses appreciate. You may destroy the rose--it does not prove that the fragrance which it emitted does not still exist even though our senses fail to appreciate it. But experiment and scientific methods have also somewhat to say upon this subject. And first, in August, 1874, twenty-two years ago, at the moment when the materialistic school was at the height of its influence, both the scientific and religious world were brought to a momentary standstill--like a ship under full headway suddenly struck by a tidal wave--when one of the most eminent scientific men of his time, or of any time, standing in his place as president of the foremost scientific association in the world, spoke as follows: "Abandoning all disguise, the confession which I feel bound to make before you is that I prolong the vision backward across the boundary of experimental evidence and discover in matter, which we, in our ignorance, and notwithstanding our professed reverence for its Creator, have hitherto covered with opprobrium, the promise and potency of every form of life."[2] [2] Prof. Tyndall's address before the British Association at Belfast, August, 1874. On that day the tap-root of materialism was wounded, and materialism itself has been an invalid of increasing languor and desuetude ever since. On the other hand, supernaturalism in every form was left in little better plight.