The problems which History is called to solve are therefore exceedingly intricate and perplexing. The Generalizations of Chemistry, conducted, as they must be, on our present basis of Knowledge, by the Inductive Method, are involved in a degree of uncertainty, not only on account of the complexity of their Phenomena, but also by reason of the absence of any method of ascertaining when all the elements of a right Generalization are obtained. In Geology, including Mineralogy, the complexity increases, and the possibility of precision and certainty decreases in the same ratio. This augmentation of complexity in the Phenomena and proportionate diminution of exactitude and certainty in respect to the Generalizations derived from them, continues at every successive degree of the scale; so that when we arrive at History, all hope of even proximate precision, and all expectation of anything like positive Knowledge, except in the broadest outline and generalization, by any application of the Inductive Method, has completely vanished. The hopelessness of a Science of History prior to the discovery of a Unitary Law and the introduction of the Deductive Method into all domains of investigation, now becomes plainly apparent. Until the occurrence of that event we shall look in vain for a true Science of History. With the advent of such a discovery, it will be possible to carry the precision and infallibility of Mathematical Demonstration into all departments of Thought, and to subject the Phenomena of History to well-defined and indubitable Laws.