We are therefore compelled by common-sense to ask when we consider Nature, What is the force or power at the back of her, which first set her going, and whence she draws the capability of performing the operations which we find her performing every day; that force or power which must be the ultimate origin of everything that is in the world? This is the great fundamental problem which the student of Nature has to face, and beside it all others fade into insignificance. It is with this that we are now engaged. We have to ask how our reason bids us answer it, and the first question which arises naturally is, What light is thrown on the subject by modern Science, of whose achievements we are all so justly proud? II REASON AND SCIENCE In studying a question such as this, we must commence by being determined, on the one hand to accept nothing as true but what our reason warrants us in believing, and on the other hand to follow the guidance of reason as far as, rightly used, it will lead us. The principle formulated[5] by Professor Huxley, as the foundation-stone of what he termed "Agnosticism," is that which must needs be adopted, and as a matter of fact has ever been adopted, by rational men. Positively--in matters of the intellect follow your reason as far as it will take you, without regard to any other consideration. And negatively--in matters of the intellect do not pretend that conclusions are certain which are not demonstrated or demonstrable. But to justify the confidence which we thus repose in it we must obviously be careful to use our reason aright, and not to attribute to it any conclusions which it does not really sanction. It is this right use of reason that is specially claimed for modern "Science,"[6] which, as we are again assured by Professor Huxley, is only another name for sound reasoning--"_Science_," he declares,[7] "_is, I believe, nothing but trained and organized common-sense_.[8] ... The man of science, in fact, simply uses with scrupulous exactness, the methods which we all, habitually and at every moment, use carelessly." There can be no sort of question that so long as men of science really act thus, and confine themselves to the treatment of matters in regard of which they can claim special knowledge, common sense bids us listen to them with respect, and even with submission. But the same common sense requires that we should satisfy ourselves that they truly deserve the character assigned them, and pretend to no knowledge on the score of Science but what their scientific methods are competent to acquire. When they step beyond this their own proper domain, whatever weight may be given to their opinions upon other grounds, they cease to speak in the name of Science. What then, we must ask, is the province of Science, and what are her methods?