First Part

Twofold genus.

¶ Nevertheless, there will still be no difference between it referring to species and the difference of the genus. ¶ Those who define it by saying that a species is that which is predicated "in what" original: "in quid," referring to essential predication of two predicables are ignorant of how to define species. It is not, in fact, appropriate to say anything except this: that it is more appropriately predicated "in what" of two universal predicables. From what, then, do you derive this? Only from certain principles and places that are proper to definitions. ¶ We say now that a genus is a genus because it is impossible for it to become a species, since there is no other, more common genus above it; and another is that which, in another respect, can become a species, since it has above itself a common genus which is itself.

Twofold species.

And similarly for species: because one is a species that it is impossible to become a genus, for there is no species less common than it; and another is that which, in another respect, can become a genus, for under it is another species less common than it.

Threefold genus: Supreme, Intermediate, Lowest.

¶ Therefore, a genus will be ordered in many ways, since there is a supreme genus, which is in no way a species. And an intermediate genus, which is a species and a genus; under it is a species, and above it is another genus. And the lowest genus, which is a species and a genus; under it there is no genus.

Threefold species: Supreme, Intermediate, Lowest.

¶ Similarly for species: because one is the lowest, under which there is no species in any way, nor is it a genus in any way; and it is the supreme species under the most general genus, and above it there is no species in any way; and there is the intermediate species, which is a species and a genus, but it is not a genus and species of the same thing.

Coordination of the subaltern predicaments.

¶ The common example of this is the category of substance original: "cathegoria sube," referring to the category of "substantia". For substance has no genus above it; under it is body; under body, indeed, is animate body; under animate body, animal; under animal, rational mortal animal the human definition; under rational animal is man; under man, indeed, are Socrates, Plato, and their children. ¶ Socrates, Plato, and their children are particulars, and substance is the most general genus, for there is no genus above it; man, indeed, is the most special species, for there is no species under him. Those things which are between these are genera and species; they are genera in respect to those below them, and species in respect to those above them. For example, body is a species of substance and is the genus of the animate; the animate is a species of body and a species of animal, in which vegetables and animals meet; animal is a species of the animate and is the genus of the rational animal, in which irrational animals and man meet; the rational animal is a species of animal and the genus of man. For man and angel meet in it.

This is said according to the way of the Latins, which Porphyry also followed in this, and this is said at the end of the chapter to be moderated by Avicenna.

¶ Therefore, the rational animal will be the lowest genus, and substance the supreme genus. Body and whatever is between them is an intermediate genus; but body is the supreme species, and man is the lowest species; the animate, which is between them, is an intermediate species; under which, in respect to that which is beneath it, is the most general and supreme genus; and because it does not have a relation to anything that is above it, it is that which is not a species; however, it has a relation to those things which are above it, and it will be the most special species and the lowest species; but in respect to those below, it is in two ways: namely, in respect to those things which are under it, in the sense that they are not species, and also in that it is predicated of them. The relation, however, which it has to that which is under it according to predication attributes to it the intention of "speciality" not relative to the genus. And this is the second intention of that which has been said. Another relation attributes to it that it is a species and not a genus, and that it is the most special species; a species, however, is not a genus, but is a species in the way we have said.

Species is equivocal to those three modes of species.

¶ The understanding of those three, however, although they are accompanying, are nevertheless diverse. But if "species" is said of each of these intentions, it will be said of these three only by participation of the name, but their definitions and understandings will be diverse. If, however, only one of them is the species, it will be said by the definition that it has; one will be its definition, and the other will be its description, which is not understood from this man, not as a sign accompanying it.

He raises doubts. Under the most special species are the ultimate particulars.

¶ Just as under the most special species there are ultimate particulars, although they are not species, so the writer, the sailor, the Ethiopian are under man. ¶ Similarly, it is not far off that above the most general genus there are predicables which

There are some predicables above the most general genera.

are not a genus, but intentions accompanying those in which genera and the genera of genera meet, just as accidents, and thus other things which are predicated of many most general things, as will be recognized later.

He modifies what was placed above in the example of the coordination of the category of substance, because those things are not said peripatetically.

¶ That difference which is attributed to substance as far as man is not correct, although it does not prevent one from understanding what is intended. For a body having a soul, since it has it, encompasses vegetables with sensibles; it does not encompass angels except by participation of the name alone, since a body having a soul will not contain angels. ¶ Similarly, he who says rational man and angel, it will not be except by participation of the name alone. For rational, which is a difference predicated of man, is not predicated of angels; and since it is so, then rational animal is not a genus of humans and angels; nor is a body having a soul a genus of humans and angels; nor is a body having a soul a genus of vegetables, angels, and animals; and since it is so, mortal is not a difference which must be placed in the definition of a rational animal by man and not-man.

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The first imposition of genus and species was according to the vulgar; then the imposition of difference was according to the wise.

A decorative drop-cap initial "D" depicts a teacher in a scholarly robe pointing toward a book on a lectern, while a smaller figure, a student, stands before him.
Difference signifies the first and the second. ¶ They are not, however, of the same intention as the intentions of genus and species. For the first position of genus was only from the common people, but the translation was from the ancients; however, the logicians first imposed the name of difference, and then they translated it.

From which it is clear that difference is analogous to three signified things.

¶ Whose first position is this: that a difference is that by which something differs from something else in some way.

Common difference.

¶ After it is therefore done thus, difference is predicated of three things, namely, prior and posterior. In such a way, indeed, that one difference is common, another is proper, and another is more proper.

Proper difference.

¶ A common difference is that through which something can differ from something, through which it can differ from it, and through which something can differ from itself at two times; the example of this is separable accidents, such as standing and sitting. For Socrates sometimes differs from Plato by this, that he is sitting and he is not, and later sometimes he is standing. This, therefore, is the imposition of the common difference of both. Similarly, Socrates sometimes differs from himself at two hours, in one of which he is sitting and in the other is not sitting. And this is a common difference.

That a difference properly said cannot be mutual in respect to the extremes.

¶ A proper difference, however, is that which is an accompanying predicable of accidents. For it is said that something differs by an inseparable accident from that which differs through it; it will always be a proper difference, such as the difference of man from a horse, which is "clean flesh."

From which it is clear that difference properly said is of two modes.

¶ This difference, indeed, is proper to man in composition with a horse, through which the horse cannot differ from man, nor is it. For it is such that in no way is it possible for a horse to have this property, or it is possible. If it were impossible to have it in any way, then it was impossible for this difference to be between them unless it was fixed. If, however, it were possible for a horse to have it, then the horse would not differ from man by it, but would agree. Therefore, a difference is that which only one of the two has.

He distinguishes between one mode of difference properly and common difference.

¶ There are some through which a species is made a difference, such as the example we placed, and it has a property; and there are some which are particulars according to which there is a difference, but not always, such as blackness, by which an Ethiopian differs from another man; for from an Ethiopian, blackness is not separated, but that other man can become black, and then blackness will not be a difference between them.

He distinguishes between common and proper difference according to mode on the one hand, and the proper difference of the first mode on the other.

¶ But when blackness is a difference, it will be proper to the Ethiopian alone; when, however, it is not his property, then it will not be his difference. A common one, however, is not so; for through it, sometimes that differs from this, and sometimes this from that. ¶ Through a common and proper difference, sometimes individuals of the same species are said to differ; by the proper difference of the members in definitions, however, individuals of the same species are not said to differ among themselves; for they accompany the nature of the species, because it happens to one of the individuals, and thus they are not said to differ by it. If, however, it were to happen to whom it happens in existence, as men have from the beginning of birth, and afterwards it is impossible for it to happen, then there can be something in this difference by which he differs from another individual, and it is impossible not to differ in any way from man, for the individual can have its cause...