It is important that this should be distinctly said, for when men eminent in science propound new theories, these theories themselves are apt to be regarded as science, and those who oppose them are accused of being opposed to science. This is the tendency which Professor Tyndall has so justly described in this very address: "When the human mind has achieved greatness and given evidence of power in any domain, there is a tendency to credit it with similar power in any other domain." Because Tyndall is great in experimental science, many are apt to accept his cosmological conclusions. Because he is a great observer in natural history, his metaphysical theories are supposed to be supported by observation, and to rest on experience. Professor Tyndall's own address terminates, not in science, but nescience. It treats of a realm of atoms and molecules whose existence science has never demonstrated, and attributes to them potencies which science has never verified. It is a system, not made necessary by the stringent constraint of facts, but avowedly constructed in order to avoid the belief in an intelligent Creator, and a universe marked by the presence of design. His theory, he admits, no less than that of Darwin, was not constructed in the pure interests of truth for its own sake. There was another purpose in both,--to get rid of a theology of final causes, of a theology which conceives of God as a human artificer. He wished to exclude religion from the field of cosmogony, and forbid it to intrude on the region of knowledge. Theologians have often been reproached for studying "with a purpose," but it seems that this is a frailty belonging not to theologians only, but to all human beings who care a good deal for what they believe.