Глава XV. О сказуемом

Every predicate is either broader than the subject or equal to it; but it never exists as a subject. The predicate is wider than the subject in the case when a more general statement is made about a less general one; The higher concepts are more general, and the lower ones are less general. The most general of all concepts is existence: therefore it speaks about everything. In fact, both substance is called being, and accident is called being. But we cannot say that a being is a substance, for not only is a substance a being, but also an accident. In the same way, genera are said about species, since they are more general, but species are not said about their genera. Species are less general than genera. Therefore, substance speaks about an animal, and an animal about a person, for both an animal is a substance and a person is a substance. But these judgments do not allow conversion, for every person is an animal, but not every animal is a person: both a horse and a dog will also be animals. Likewise, not every substance is an animal, for both stone and wood are substances, but they are not animals. In a similar way, a species speaks about the individuals it embraces, i.e. hypostases, since he belongs to a greater community than them. But the individual, or hypostasis, does not speak about the species, for the hypostasis has less commonality than the species. Therefore, Peter is a man, and Paul is a man; but not every person is Peter or Paul: there are other hypostases of the human species. As for differences, they are expressed both about the species to which they belong and about the individuals of these species, for differences belong to a greater commonality than to species. Thus, the “reasonable” has a greater commonality than the species - man: every person is reasonable, but not every rational being is a person; for example, an angel, although intelligent, is nevertheless not a person. The predicate is such when it is wider than the subject. The predicate is equal in scope to the subject when it allows inversion. Thus, properties are expressed about the species to which they belong; and species speak about their properties. Every person has the ability to laugh, and everyone who has the ability to laugh is a person. For although they say about a monkey that it laughs, it does not laugh with its heart, but only in appearance, since it is an imitative animal. Thus, when the genus is expressed about the species, the difference is about the species, the species is about the individual; then the predicate is wider than the subject. When properties are expressed, the predicate is equal to the subject. Such a predicate is called purely invertible and allows mutual predication with the subject. You might be interested in: