Here one first envisions the two concrete cases—the original precedent and the new case—then moves to their concomitant, the universal meaning they share, and from there to the concomitant of that concomitant, namely the ruling itself.

One must realize that the ruling necessarily follows from this shared universal; this is what is there called the major premise. After that, one proceeds to affirm the consequent for the first particular subject.

In reality, the two modes of reasoning are the same; they differ only in the way the proof is pictured and arranged. The underlying fact that makes either of them a proof—that it entails the conclusion—is one and the same.

It is sheer injustice and ignorance when some people illustrate analogy by representation with the example: “The heavens are composite; therefore they are contingent, by analogy with man,” and then raise objections to that analogy that pertain solely to the specific material involved. Those very objections would arise—indeed, with further force—were the argument cast as an analogy by subsumption; for if one said, “The heavens are composite, and every composite is contingent,” the same questions and more would surface.

However, when analogy by subsumption is applied to a matter whose material is well-known and evident, there is no difference between it and analogy by representation; in fact, representation may at times be clearer, which explains why intelligent people often reason by means of it.

Their statement that a definition cannot be obtained by example is valid only when the example fails to distinguish the thing defined from anything else—that is, when it does not allow one to grasp the property that inseparably accompanies the defined entity, both positively and negatively, appearing wherever it appears and disappearing wherever it disappears. The distinguishing definition is precisely that by which one comes to know such an inseparable concomitant in both directions. Whatever achieves this has set the defined thing apart from everything else, and that, according to the majority of investigators, constitutes a definition; they do not permit the inclusion of the broad generic class within the definition.

Accordingly, if the aim is merely a nominal definition—suppose a non-Arab asks about the referent of the word “bread,” so one shows him a loaf and says, “This.” He may then understand that the term applies to everything that is bread, whether it takes the shape of a loaf or some other form. A fuller discussion of this matter has been given elsewhere