 Sortal properties are typically expressed by count nouns like “desk” and “cat” and are taken to encode principles of individuation and persistence that allow us to objectively count objects. For example, there is a fact of the matter regarding how many things in this room instantiate being a desk and being a cat. On the other hand, non-sortal properties such as red or water do not allow us to count in a similarly obvious way. This distinction is often appealed to in contemporary metaphysics (P. Strawson 1959: ch. 5, §2; Armstrong 1978a: ch. 11, §4), where, in contrast, the traditional one between genus and  species  plays a relatively small role. The latter figured conspicuously in Aristotle and in much subsequent philosophy inspired by him. We can view a genus as a property more general than a corresponding species property, in a hierarchically relative manner. For example, being a mammal is a genus relative to the species being a human, but it is a species relative to the genus being an animal. The possession of a property called differentia is appealed to in order to distinguish between different species falling under a common genus; e.g., as the tradition has it, the differentia for being human is being rational (Aristotle, Categories, 3a). Similar hierarchies of properties, however without anything like differentiae, come with the distinction of  determinables and determinates,  which appears to be more prominent in current metaphysics. Color properties provide typical examples of such hierarchies, e.g., with red and scarlet as determinable and determinate, respectively.