Law, again, must have been much studied, and so, too, was theology. The library of Nineveh, however, from which so much of our information has come, gives us an exaggerated idea of the extent to which the pseudo-science of omens and portents was cultivated. Its royal patron was a believer in them, and apparently more interested in the subject than in any other. Consequently, the number of books relating to it are out of all proportion to the rest of the literature in the library. But this was an accident, due to the predilections of Assur-bani-pal himself. The study of omens and portents was a branch of science and not of theology, false though the science was. But it was based upon the scientific principle that every antecedent has a consequent, its fallacy consisting in a confusion between real causes and mere antecedents. Certain events had been observed to follow certain phenomena; it was accordingly assumed that they were the results of the phenomena, and that were the phenomena to happen again they would be followed by the same results. Hence all extraordinary or unusual occurrences were carefully noted, together with whatever had been observed to come after them. A strange dog, for instance, had been observed to enter a palace and there lie down on a couch; as no disaster took place subsequently it was believed that if the occurrence was repeated it would be an omen of good fortune. On the other hand, the fall of a house had been preceded by the birth of a child without a mouth; the same result, it was supposed, would again accompany the same presage of evil. These pseudo-scientific observations had been commenced at a very early period of Babylonian history, and were embodied in a great work which was compiled for the library of Sargon of Akkad.