Collected Works

3. differentia differentia.

not but one certain one. ¶ The third differentia difference is that the genus generic category is predicated of each of its species specific classifications primarily and does not convert: for one does not say that every animal is a man, just as it is said that every man is an animal; but a proprium property does convert: for every man is naturally apt to laugh, and everything apt to laugh is a man. This, however, is the difference between the genus and the proprium of a subaltern species. ¶ After this, however, follows another difference contained within it, namely: that although a proprium has a species, and it has a genus just as it does, it nevertheless does not have that which other species have, just as a genus has it.

.4. differentia.

¶ Likewise, another difference is elicited from the first, namely: that from the destruction of the genus, the proprium is destroyed, but it does not convert. ¶ If anyone wishes to accept this alongside the difference that is by prior and posterior, the reasoning will not be lacking, but it will be laborious for him.

.5. differentia.

Agreement of genus and accidens.

Truly, the genus and the accidens accidental attribute agree in this: that each of them is predicated of many things. ¶ But this sharing is general: for if at least it were said of many, the species would assign a proper sharing between the genus and the accidens, even if it did not assign another sharing.

First difference of genus and accidens.

¶ The first difference is that the genus is prior to the species, as you already know; the species, however, is posterior, for it is that which happens original: "accidit" to it. For if what happens to it comes from its specialization, then the specialization is already constituted from the difference; and from then on, whatever happens, happens to it, which we have already suitably explained. If, therefore, it is from external accidents, the species will already be made a subject, apt to receive that external accident. This difference is also between the genus and the proprium.

Second difference.

¶ Likewise, another difference is that those things which are under a genus agree in it equally; those which are under an accidens do not agree in it equally. ¶ This assignment, however, is deformed: for we have shown the difference that is between their subjects, and it is also necessary to show the difference within itself. ¶ It would be more fitting to say that the genus is not predicated of its inferiors except causally, but the accidens [is predicated] equally; and the difference would be known in the first assignment. One ought to say that accidents are sometimes predicated unequally; or if not that, then that all accidents are predicated unequally, such as "quadrangle" and "triangle" and similar things, the reading of which makes one opine that every accidens is predicated unequally.

Objection.

¶ Consider, therefore, from this: since some accidents can be predicated unequally, what will prevent this from also occurring in properties?

Solution.

¶ And perhaps because the accidens is more common, and the proprium is equal, it is attributed to this which is not attributed to that.

.3. difference of genus and accidens.

¶ After this, however, follows the difference: that accidents exist in individuals primarily, but genera and species are posterior to individuals. ¶ This difference is also oblique and involved: for one ought to say that accidents are in individuals primarily, but genera and species are not in individuals primarily, or say that genera are prior to species, but accidents are not. For who prevents something from being first, so that it may have being primarily?

.4. difference of genus and accidens.

¶ Likewise, another difference is that accidents are predicated of individuals with no intermediary in which they might agree, as the species is; the genus, perhaps, is not predicated in such a way. The name of the species, however, was not necessary for him. For he himself did not intend to assign a difference except between the genus and the accidens.

.5. difference.

¶ After this, however, is the difference that genera are predicated in "what it is," but accidents are not. This is a difference between the genus and the proprium which he omitted there.

Agreement of differentia and species.

The differentia and the species agree in this: that they are predicated of those contained under them equally, and in this: that they are subaltern; but this agreement is between the genus and the differentia, which he omitted there.

First difference between differentia and species.

Therefore, it sometimes responds to "what it is" for animals, but through an accidens.

They differ, however, in this: that the species is predicated in "what it is," but the differentia in "what kind it is." For although "man" may respond appropriately to "what kind" among animals, it does not have this primarily, nor from itself, but from the rational cause, which has already been treated at length.

.2. difference.

Note this limitation: for speaking absolutely, this difference is false, and understand Porphyry in this way.

¶ The second difference is that the species is not predicated except of many that differ in number only, but the differentia is predicated of many that differ in species. This is the discrepancy between the differentia and the species specifically, not between the differentia and the species absolutely.

.3. difference.

¶ The third discrepancy is that the differentia is posterior to the species, and he placed an example of this according to destruction, saying that removing "rational" removes "man," but removing "man" does not remove [rational]—for an angel is rational. ¶ He did not place the differentia and the species which are simultaneous, but he took the differentia of the genus of man and compared it to man. But if someone were to say that the species is prior to the differentia which is "rational," he would be straying from the truth. ¶ Similarly, if one were to place here the differentia and species which are equal, the differentia is prior to the species insofar as it is its cause, for which reason it has being: whose comparison to the species is as the comparison of form to the composite.

Note the declaration, because the expositors of Porphyry explain this otherwise.

He does not remove "man," for an angel is rational. ¶ Nor did he place the differentia and species which are simultaneous, but he took the differentia of the genus of man and compared it to man. But if someone were to say that the species is prior to the differentia which is "rational," he would be straying from the truth. ¶ Similarly, if one were to place here the differentia and species that are equal, the differentia is prior to the species insofar as it is its cause, for which reason it has being: whose comparison to the species is as the comparison of form to the composite.

.4. difference.

¶ Likewise, he assigned another difference, saying that two differences sometimes agree to constitute one species, but two species do not agree to constitute a third species; and he placed the example of two differences: "rational" and "mortal." It is clear, however, that these are not equal in order, as we have already explained.

Double understanding of this difference.

¶ This discrepancy is called "one from two" and is according to respects. Either [it is understood] as when two differences are placed in the stated manner—that is, "sensible" and "movable by will"—or [it is understood] as when it is said that two differences, distinct in order, when they agree, through their agreement with that with which they agree, another species results, distinct from each of them. Diverse species, distinct in order, do not agree such that from them another species results outside of each of them, for from them is the part minus the commonality; as for the commonality, there is nothing formed from their concurrence, but that which is from one of them. Two diverse species, however, which are not distinct in order, do not agree in any way.

First objection.

¶ Someone could say that "rational" and "mortal" are in themselves two species of some things, although they are not two species of man; fittingly, however, they made a species.

Second.

¶ Similarly, when many different species of nature agree, from their agreement a third species results: just as from the agreement of quality and ternarity, "generality" likely referring to "species-ness" or classification is made, which is a third species from them.

Solution to the first.

¶ To this, we answer that the intention of considering this discrepancy is other than this of ours; for the intention is of those things which are predicated of others to which they are common. But when they are differences—like "rational" and "mortal," which are predicated of some just beings—and when they come together, they make a certain third thing, which will be one of the species of those things. Those things, however, will be for them just as individuals are under a species; and "rational animal" is within the being of those individuals, but it is not within the being of "rational" or "mortal." Therefore, "rational" and "mortal" are not two species in comparison to those, although they are predicated of them; otherwise, they would be intermediaries between those individuals and the genus which is "animal," for there are two subaltern species, not two divisive differences.

They imply the solution by reason.

¶ Therefore, in differences, one finds two differences constituting one common species under them, which is not found in species. ¶ But that there are diverse species from whose concurrence a species is made—whose subject might be outside the subjects of those—this is not denied.

First agreement of differentia and proprium.

¶ The differentia and the proprium agree in this: that they are predicated of those contained under them equally. But you ought to know that this does not happen except in some properties, among which is the common property which is specific and formal. For all "risible" capable of laughter things are equally risible, just as rational things are equally rational.

Second agreement.

¶ And they agree in this: that all have those things, and always. This is because the common property has an inherent species.

First difference of proprium and differentia.

¶ They differ, however, in this: that a true proprium is not of but one species. A differentia, however, is sometimes of many; you already know this.

Second difference.

¶ After this follows another difference, almost the same or similar: that a differentia is sometimes not predicated reciprocally—for not everything that is rational is a man—but a true property converts.

Agreement of differentia with an inseparable accidens.

¶ The differentia and an inseparable accidens agree in this: that the subject has those things.

First difference between differentia and accidens.

¶ But they differ in this: that the differentia contains the species of which it is the differentia, but it is not contained by it. ¶ That man also said that accidents contain things other than those they have, from the fact that they are common; and they are contained by them, in that the subject is not properly receptive of any of them which is in it, but is the subject of another; and therefore it contains that, just as it contains an accidens which does not have to be predicated of one only of its subjects, but happens to others.

He secretly criticizes Porphyry.

¶ But that man forgot what he had said, namely, that one subject sometimes has many differences which...