9. Those historical events are signs in this sense that their proper and intelligent study provides proofs of the fact that there is only one God: and that the law of retribution is universal and is based absolutely on the differentiation between the knowledge and moral practice of the truth and falsehood: that this law also requires another world (the Hereafter) for its due fulfillment. Moreover, these events contain signs that serve as warnings against the evil consequences of building up systems of life on false creeds and theories, and help one to learn lessons from them.