and that which necessarily entails it; the two share generality and specificity, being unqualified and being individually determined. Thus, when sharing and distinction, agreement and difference are considered with reference to the mind and external reality, whatever two things share exists in the mind, while each of them is distinct in external reality. Two animals that share animality share unqualified animality, whereas each is distinguished from the other by the actually existing animality peculiar to it. Likewise, two rational beings share rationality, while each is distinguished from the other by the rationality peculiar to it.

Things existing in external reality bear similarities and resemblances to one another, as well as differences and oppositions; yet nothing shares another thing’s very essence or any of its attributes.

Their claim regarding the first division is that it is like the differentiae of species falling under a single genus: the nature of that genus is a necessary concomitant of the natures of those differentiae, just as existence, existence and unity, resemblance and difference, opposition and distinction are necessary concomitants of many realities.

They may be told:

The differentiae of species—such as rationality, the capacity to neigh, and the like—are the distinguishing characteristics of animal species, such as horses, humans and others falling under the genus animal. If it is said that the nature of the genus, namely animal, is a necessary concomitant