If they say, “This knowledge is self-evident or necessary,” this amounts to saying that these universal propositions are known self-evidently and necessarily, and that the soul cannot help knowing them. If this is true, then knowledge of particular entities and the various kinds of universals also arises in the soul self-evidently and necessarily—as indeed happens. For rational people are more certain about individual objects of sense perception than about universals, and more certain about universal propositions concerning species than those concerning genera. Knowledge of particulars reaches the natural disposition first, so its certainty about them is stronger.
As the intellect grows stronger, the scope of its universals broadens. Accordingly, one cannot say that knowledge of individuals depends on knowledge of species and genera, or that knowledge of species depends on knowledge of genera. Rather, a person may know that he himself is capable of sensation and voluntary movement before knowing that every human being is so; and he may know that human beings are so before knowing that every animal is so. Thus, his knowledge that other animals are capable of sensation and voluntary movement does not depend on demonstration.
When he knows that this judgment applies to all other people and animals, the soul arrives at that judgment through knowing that the unobserved is like the observed, or that it shares with it the cause that necessarily entails its capacity for sensation and voluntary movement, and through similar forms of analogical and causal reasoning used by jurists to establish rulings of Islamic law. Yet these people claim that such reasoning yields only conjecture, whereas their own syllogism yields certainty. We have explained elsewhere that this claim of theirs is among the most untenable of claims, and that