Many speculative thinkers follow a particular method of proving a conclusion and say: “The desired conclusion can be reached only by this method.” Their exclusion of other methods is incorrect, even if they are right about the validity of their own method. For the greater people’s need to know something, the easier Allah makes it for their minds to recognize the evidence for it. Thus, the proofs of the Creator’s existence and oneness, and the signs and proofs of prophethood, are exceedingly numerous, as are the ways people come to recognize them.

Most people have no need for many of these methods. They are needed only by those who know no others or who turn away from other methods. For some people, the subtler, more obscure, and lengthier a method is, and the more premises it contains, the more beneficial it is. This is because their minds have become accustomed to examining subtle matters. If a proof has few premises, or its premises are obvious, they take no pleasure in it. With such people, methods of speculative theology and logic, among others, may be used because they suit their habitual way of thinking—not because knowledge of the desired conclusion invariably depends on them.

Some people feel that knowing what most people know, or what even those of no particular intelligence can understand, does not distinguish them from others in knowledge. They therefore love to learn about obscure, subtle matters involving many premises. For this reason, many scholars of the Sunnah are drawn to studying sound and exact sciences, such as algebra and intricate problems concerning inheritance, bequests, and circular calculations. Such knowledge is sound in itself.

“The science of inheritance is of two kinds”: legal rulings and calculation.

Knowledge of the legal rulings is of three kinds. The first is knowledge of the rulings according to the school of a particular jurist. Next comes knowledge of the Companions’ opinions concerning matters