It was, then, fitting that the name joined, at least in tradition, with the final form of that system, should be that of a controversialist. But this man, Abu Bakr al-Baqilani the Qadi, was more than a mere controversialist. It is his glory to have contributed most important elements to and put into fixed form what is, perhaps, the most fantastic and daring metaphysical scheme, and almost certainly the most thorough theological scheme, ever thought out. On the one hand, the Lucretian atoms raining down through the empty void, the self-developing monads of Leibnitz, pre-established harmony and all, the Kantian “things in themselves” are lame and impotent in their consistency beside the parallel Ash‘arite doctrines; and, on the other, not even the rigors of Calvin, as developed in the Dutch confessions, can compete with the unflinching exactitude of the Muslim conclusions. [Sidenote: ASH‘ARITE METAPHYSICS] First, as to ontology. The object of the Ash‘arites was that of Kant, to fix the relation of knowledge to the thing in itself. Thus, al-Baqilani defined knowledge (_ilm_) as cognition (_ma‘rifa_) of a thing as it is in itself. But in reaching that “thing in itself” they were much more thorough than Kant. Only two of the Aristotelian categories survived their attack, substance and quality. The others, quantity, place, time and the rest, were only relationships (_i‘tibars_) existing subjectively in the mind of the knower, and not things. But a relationship, they argued, if real, must exist in something, and a quality cannot exist in another quality, only in a substance. Yet it could not exist in either of the two things which it brought together; for example, in the cause or the effect. It must be in a third thing. But to bring this third thing and the first two together, other relationships would be needed and other things for these relationships to exist in. Thus we would be led back in an infinite sequence, and they had taken over from Aristotle the position that such an infinite series backward (_tasalsul_) is inadmissible. Relationships, then, had no real existence but were mere phantoms, subjective non-entities. Further, the Aristotelian view of matter was now impossible for them. All the categories had gone except substance and quality; and among them, passion. Matter, then, could not have the possibility of suffering the impress of form. A possibility is neither an entity nor a non-entity, but a subjectivity purely. But with the suffering matter, the active form and all causes must also go. They, too, are mere subjectivities. Again, qualities, for these thinkers, became mere accidents. The fleeting character of appearances drove them to the conclusion that there was no such thing as a quality planted in the nature of a thing; that the idea “nature” did not exist. Then this drove them further. Substances exist only with qualities, _i.e._, accidents. These qualities may be positive or they may be negative;