Yet what is all this but a confirmation of the declaration long ago made that "the works were finished from the foundation of the world" (Heb. 4:3)? True, the energy we are constantly employing seems to come to us from the sun; but we must remember that the sun and its family of the solar system, including the earth, were all made at the same time, that they are bound together as parts of an indissoluble whole. Accordingly, no one can say that the total amount of energy called into existence at the creation of our solar system is being added to at the present time. At any rate, so far as modern science can judge of the matter, the total amount of energy available for our world _is a fixed quantity_; and its amount and the terms on which it was to be available for our use were fixed or finished "from the foundation of the world." While it is a very significant fact in this connection that with all the multiform speculations which have been made as to the physical source of the sun's heat, no explanation wholly satisfactory has yet been made as to how this energy coming to us from the sun is constantly replenished or maintained. II The desire to find a material cause for all phenomena is instinctive in the human mind, and has proved the chief impetus in a thousand discoveries. And yet, unless we are on our guard, it is liable to be a source of real error whenever we are dealing with the deeper problems of thought. For when we have pushed our way into the inner sanctuary of any department of nature, we almost invariably come upon a deep chasm that we can pass over only by building a bridge of words. Some of these verbal bridges have been decorated with very dignified names, such as "the luminiferous ether," "gravity," "chemical affinity"; and when we have shifted from the one side of the chasm to the other we impose upon the credulity of the public (and even ourselves) by giving out the impression that these words represent the real objective bridge on which we crossed.