and inward awareness; they are known through innate disposition and rational proofs, through scriptural proofs—the Book, the Sunnah, and consensus—through reports transmitted from the prophets by numerous independent chains, and through the agreement of rational people whose innate dispositions are sound.

When they argue through reflection, analogy, rational reasoning, and demonstrations like those invoked by their opponents—indeed, through demonstrations sounder than those and true in themselves—they establish this in several ways. The first contains an important, comprehensive principle, and may be stated as follows:

There is no doubt that reasoning by analogy from the observed to the unobserved is sometimes valid and sometimes invalid. Rational people agree on this. They agree that a person cannot assume that everything he has not perceived resembles what he has perceived, for many things exist that he has neither perceived nor perceived anything resembling them in every respect. Indeed, among the things beyond his perception are things he does not know, or knows through reports insofar as they can be made known to him in this way. Likewise, there are things he knows through analogy and inference from what he has observed. This is what is known through reason, just as the former is what is known through reports.