Logic by Nicephorus Blemmydes and Topics by Boethius

long discourses, and those taking theorems about nature in a detailed manner x; since those very brief [definitions] are not those that are strictly definitions, [which are] indicative of nature's theorems, such as the apothegms of words or laws; but he who claims [to define] even such things; for this reason, the phrase "indicative of the nature of the underlying thing" has been added; and the virtue of a definition is to be convertible with the defined; for example, as in the example of defining a human: a rational, mortal animal, receptive of intellect and knowledge; and they call it an animal, separating it from the inanimate; from the plants; and from those who exhibit nature [as an] animal; such as a stone; even if it is an animal or is not? an animal. For this reason, "rational" is added, separating it from irrational animals; since even to angels a rational essence is mistakenly attributed; they [the myth-makers] monstrously describe bodies as rational animals, for this reason "mortal" is added, distinguishing it from immortal animals; but also nymphs are mythologized to be long-lived; rational and long-lived animals; nevertheless, however, mortal by nature, where they are also known by mixtures [and] not by technical ways, according to which...