Any later scholar who claims that learning logic is a collective obligation, or that it is a prerequisite for independent juristic reasoning, thereby demonstrates his ignorance of both the revealed law and the usefulness of logic. The falsity of this claim is necessarily known in the religion of Islam. The best of this community—the Companions, those who followed them in righteousness, and the leading scholars of the Muslims—knew what was required of them and what would perfect their knowledge and faith before Greek logic became known.

How, then, can it be said that knowledge cannot be trusted unless weighed by logic, or that human beings’ natural faculties generally become sound only through it? If they say, “We do not maintain that people need the logicians’ terminology, but rather the concepts by which knowledge is weighed,” the answer is: There is no doubt that the unknown can be understood only through what is known. People need to weigh what they do not know against what they know. This is among the balances Allah has sent down, as He says:

“It is Allah who has sent down the Book in truth and the balance.”

And He says:

“We certainly sent Our messengers with clear proofs and sent down with them the Book and the balance.”

This is found both in our community and in other communities among people who have never even heard of Greek logic. It is therefore clear that peoples have no need of the logical concepts that the logicians expressed in their own language, namely, their discourse on secondary intelligibles.

For the “subject matter of logic” is intelligibles insofar as they serve to attain knowledge of what is not yet known. It examines the properties of secondary intelligibles: the secondary relations that attach to essences considered without qualification, if these lead to the acquisition of what has not yet been acquired or assist in doing so—not in a particular instance, but according to a universal rule. They claim that the logician examines the genus of proof, just as