There is thus, with great modifications, an analogy between the prophet and the scientific observer of the present day. Men of science are able to affirm the certainty of natural phenomena by their knowledge of the laws and principles of nature. Certain forces being present, certain results must come to pass. The Old Testament prophets, working in history, a sphere where the problems were infinitely more complicated by the presence and powerful operation of man's free-will, seized hold of principles as conspicuous and certain to them as the laws of nature are to the scientist; and out of their conviction of these they proclaimed the necessity of certain events. God is inflexibly righteous, He cannot utterly destroy His people or the witness of Himself among men: these were the laws. Judah shall be punished, Israel shall continue to exist: these were the certainties deduced from the laws. But for the exact conditions and forms both of the punishment and its relief the prophets depended upon their knowledge of the world, of which, as these pages testify, they were the keenest and largest-hearted observers that ever appeared. This account of prophecy may be offered with advantage to those who are prejudiced against prophecy as full of materials, which are inexplicable to minds accustomed to find a law and reason for everything. Grant the truths of the spiritual doctrines, which the prophets made their premises, and you must admit that their predictions are neither arbitrary nor bewildering. Or begin at the other end: verify that these facts took place, and that the prophets actually predicted them; and if you are true to your own scientific methods, you will not be able to resist the conclusion that the spiritual laws and principles, by which the predictions were made, are as real as those by which in the realm of nature you proclaim the necessity of certain physical phenomena--and all this in spite of there being at work in the prophets' sphere a force, the free-will of man, which cannot interfere with the laws you work by, as it can with those on which they depend.