Upon the question whether Humanity is, after all, to cast in its lot with the grass that withers and the beasts that perish, the whole foregoing argument has a bearing that is by no means remote or far-fetched. It is not likely that we shall ever succeed in making the immortality of the soul a matter of scientific demonstration, for we lack the requisite data. It must ever remain an affair of religion rather than of science. In other words, it must remain one of that class of questions upon which I may not expect to convince my neighbour, while at the same time I may entertain a reasonable conviction of my own upon the subject. In the domain of cerebral physiology the question might be debated forever without a result. The only thing which cerebral physiology tells us, when studied with the aid of molecular physics, is against the materialist, so far as it goes. It tells us that, during the present life, although thought and feeling are always manifested in connection with a peculiar form of matter, yet by no possibility can thought and feeling be in any sense the products of matter. Nothing could be more grossly unscientific than the famous remark of Cabanis, that the brain secretes thought as the liver secretes bile. It is not even correct to say that thought goes on in the brain.