Vat.gr.244

Since we are about to begin discussing genus, the term "genus" has been found to have three meanings among the many homonymous expressions. I shall take up the account—that is, the difference and the theoretical study—as the philosophers understand the meaning of genus. The meaning of genus is that under which the species is subordinated. This is the definition of genus that the philosophers have provided in an unwritten form, meaning a definition not provided by writing or by a specific word, because it is not possible to define genus through its essential properties.

What is genus
and how is it
studied
by the
philosophers,
and how do they
provide
its
definition?

A beginning of such a genus is that which is under itself, and it seems that the multitude also holds everything that is under itself. Since genus is used in three ways, the account among the philosophers concerns the third. They have provided a descriptive definition by saying that genus is that which is predicated of many things that differ in species in the question of "what it is." For example, "animal." Among things predicated, some are said of only one thing, such as individuals like Socrates and the like. This is said of many things, such as genera, species, and differences.

The descriptive definition
is called "essential" by those who say it is what constitutes,
for example, "animal, rational,
mortal, capable of mind
and knowledge." Of such
beings, most
are essential; every
system that is essential
is studied as the essence.
For example, "grammarian."
This concerns passions,
broad nails,
and "risible." For example, man is an animal,
rational, mortal, capable of mind
and knowledge.
Having defined it, they provided it
by taking the essence.

Philosophers appear to describe
genus
not from essential properties,
but from
accidental ones. For example,
"that which is predicated of many
things that differ in species
in the question of 'what it is'."
For to be predicated
is an accident
to the genus.
For being an animal is not predicated
by anything, but when
it leads the particulars under it,
then it is called so.

Having called man a walking, broad-nailed, grammatical animal, he gave a descriptive definition, taking it from non-essential properties. If one says again that he provided the genus, but this place is a genus for him, he has provided a homonymous expression not according to nature, but one that is not worthy of what has been accomplished. For the nature of genus can, through description, obtain another account that is studied by those things said from itself. As for analysis, it refers to those things from the ancestors of those being genealogized. The genus, such as Heracles and those following him—that is, the many horses and oxen. But the nature of the species is that nature. But it is through man, and it is through the ox. But perhaps you are chiding. But essence, genus is not said as "what it is" to be predicated, because in the case of most things, "what it is" is the species. For example, animal is predicated of man, the ox, and the horse, and the rest. But for example, Socrates, Plato, and Alcibiades are positioned under one name being called. The account of itself is of the accidents of the species, for the genus must also be common, to be studied by property over many, for example, "white," "black," "to be moved," and "to be healthy." Such things are not called genera but properties and accidents of species.