Thomas Compton Carleton, S.J., was a seventeenth-century English Jesuit philosopher-theologian. His major philosophical work, the Philosophia Universa, is a model of Jesuit pedagogical practice insofar as it stays true to a fundamentally Aristotelian vision of philosophy, as required by the Jesuit Ratio Studiorum, but expresses originality in its theses and tenor.

We have translated several passages from his masterpiece about Thomistic objective distinctions, where he solves several objections.

With Nominalism and its modified variations, an unnatural and unhealthy trend was systematically developed, that refused to see or acknowledge in the physical world universally valid principles of being and of explanation and investigation of being. Distinctions firmly rooted in the realm of fact, but also higher in order than the eye or finger can tell, grew thinner and thinner, threatening the foundations for the understanding of causes, qualities and ends, and eventually anything at all.

A distinction is nothing but a mutual negation of identity. Indeed, the first ratio of distinction is affirmation and negation, or to be and not to be. Real distinction is the mutual negation of real identity between elements; for example, between whiteness and blackness. Distinction of reason is divided into two main categories: one called of reasoning reason (the act of a person); the other, of reasoned reason (the act of a thing about which reason is given).

The distinction of reasoning reason is made by the intellect out of its mere invention and fertility, no occasion or grounding provided by the thing itself. The distinction of reasoned reason is made by the intellect with a grounding in the thing and not out of its mere fertility. The main distinction of reasoned reason is also called objective or metaphysical, and it is found between two objective concepts or perfections that do not include each other, as animal and rational. The common Thomist School grounds this kind of distinction in the thing itself that is distinguished at a certain eminence in which diverse formalities or perfections are united. This eminence in the thing is called a virtual distinction, because the same form somehow does all the functions proper of several lower forms; for example, in the same rational soul the perfections of the vegetative, sensitive and rational life are united.

To “ground” or “root” serves as an analogy for derived firmness. Understood ratios have two firmnesses: that of their own esse—and this they derive from the intellect, as other accidents derive it from their subjects—and the firmness of their truth—and this they derive from the thing to which they are conformed; indeed, from the fact that a thing is or is not, speech and intellect contain truth or falsehood.


There is an intellectual act that cognizes the animal and not the rational; therefore, some distinction takes place by this intellectual act on the part of the object between animal and rational. Proof of the antecedent: when I see a man from afar, I see no marks of the principle of reason; therefore, by the notice had from my location, I cannot know the rational, but only the animal or principle of feeling. Proof of the antecedent: I see only sensitive operations, but these only produce the species of the principle of feeling, not those of the principle of reason; whence, as regards this intellectual act, it is the same as if the principle of reason were not there and the perceived moving creature were a horse or a lion. Therefore, by this mere act, I can cognize the animal or principle of feeling but not the rational, thus, by this act, I distinguish those predicates from each other.

First Evasion

Since the principle of reason is identified in that case with the principle of feeling, explicit and clear knowledge of the principle of feeling brings with itself explicit and clear knowledge of the principle of reason.

First Answer to the First Evasion

To know and not to know the same thing clearly and explicitly, is not less contradictory than to know and not to know at all. Therefore, animal and rational being identified, it will be equally possible not to know the rational while knowing the animal, and not to know the rational explicitly while knowing the animal explicitly.

Second Answer to the First Evasion

In the referred case, the intellect has no indication of anything rational, since it sees no operations of reason; whence, if that object were only animal, the intellect would be affected no differently. Therefore, the intellect is provided with no rational species from that object, therefore, in that case, it can only cognize the principle of feeling and thus distinguish it, or it can cognize neither principle. Indeed, we see with the corporeal eye nothing spiritual anywhere, though the ratio of being and other ratios common with ratios or predicates of other things are there. However, because we cannot see one predicate with the corporeal eye there, we can see none. The same holds true in the knowledge of grace and supernatural things with respect to the natural strengths of the angelic intellect. Thus, if someone had no more than strength of magnitude 4 to lift weight of magnitude 6 and were unable to separate those 2 degrees from the others, then, since he would be unable to lift the whole load, he would lift none of it. Likewise, therefore, in our present case, if the intellect were unable to intentionally divide the principle of feeling from the principle of reason in an object, it would cognize nothing of the object, since the intellect would lack the sufficient intellectual strengths for that task, to wit, the co-principle, namely the species on the part of the object that would suffice to cognize the rational, since it would have no more strengths than those leading to cognize the animal as abstracted from the sole operations of feeling.

Second Evasion

That animal is distinguished from rational cannot be deduced from the inability of the intellect to discern that the principle of feeling is the principle of reasoning. Thus, a countryman knows someone to be a man whom he does not know to be a rational animal, and yet man is not distinguished from rational animal.

Answer to the Second Evasion

The antecedent is distinguished: it is denied that that countryman does not know the man to be a rational animal as to the conceived reality; it is granted that he does as to the words, i. e., that he does not know what “rational animal” means. Indeed, if anyone asked the countryman whether a man can feel and understand, he will answer “yes”, and he will answer that by knowing someone to be a man, he can know whether that man can feel and understand. If he does not know this, he does not know what it is to be a rational animal; indeed he does not even know what it is to be a man except as to the word and according to the shape or to certain external signs, as a wolf and a dog do not know what it is to be a man when the wolf flees and the dog approaches to his master.


Let us take the intellectual act of asserting, “Man as an animal is a principle of feeling”. What does this proposition mean? The Nominalist may answer: it means that man as compared to sensitive operations is an animal. in the contrary sense, first, that comparison is an act of the intellect, but the act that constructs that proposition does not reflect on itself. in the contrary sense, secondly, in all other reduplicative propositions, such as “the sun by being bright expels darkness”, it is not themselves that those acts reflect upon and reduplicate, but something intrinsic to the object. Therefore, it would be entirely gratuitous to state that the intellectual act reduplicates itself here. in the contrary sense, thirdly and principally, in that proposition only the virtue of feeling is reduplicated, but the act of the intellect in no way is the principle or virtue of feeling. The conclusion of this is patent.


Every distinction, according to Nominalists, consists in acts, therefore since the act representing animal is really distinguished from the act representing rational, the distinction is either none or real, since the complex resulting from the whole man and the intellectual act comparing him to sensitive operations is really distinguished from the complex resulting from the same whole man and another intellectual act comparing him to intellectual operations. But the man is always the same in either complex, therefore either animal is not at all distinguished from rational, or it is distinguished really; even as one hand is distinguished from another in which the same soul is given, so is this same man under two really distinct acts.


“Abstraction by the intellect is twofold—when the universal is abstracted from the particular, as animal abstracted from man; and when the form is abstracted from the matter, as the form of a circle is abstracted by the intellect from any sensible matter. The difference between these two abstractions consists in the fact that in the abstraction of the universal from the particular, that from which the abstraction is made does not remain; for when the difference of rationality is removed from man, the man no longer remains in the intellect, but animal alone remains”. (Summa th. I, 40, 3 co.)


Prior to the operation of the intellect, prior to the distinguishing act, there was in the object no actual distinction, but only an aptitudinal or fundamental one, or, as others call it, virtual, and the intellect with its shrewdness separates and divides these really identified predicates, so that, when one of them is represented or known, the other is not represented and accordingly behaves as if it were fundamentally absent from the object, not indeed by a negative separation—that is, denying rational to be united with animal, for this would be false—but by a prescinding separation, i. e., by knowing animal without any mention of rational being made by that intellectual act. Therefore, this conclusion is grounded in two factors: the fertility of the object and the subtility of the intellect. This is explained as follows.

First Remark

The more excellent a thing is, the more perfections it contains, which are identified really in it but scattered in other things.

Second Remark

The act of the intellect contains two ratios: that of a physical form and that of an intentional form. As a physical quality it is intrinsic to the subject; as an intentional quality it is directed into the object. As physical it inheres; as intentional it represents. As physical, it exacts a subject proportional to itself, namely spiritual, vital, etc.; as intentional it exacts no proportion with the object, but is equally and indiscriminately directed to a body, a spirit, a substance, an accident, a created being, the uncreated being, being, not being, everything. Finally, inasmuch as the quality is physical, it has a determined sphere and is circumscribed by certain boundaries and limits; but inasmuch as it is intentional, it is contained by no limits and is bound by no circumstances of place and time, but represents as well an absent object as a present one, as well a past as a future one, indeed what neither is nor can be.

Intellection is Stronger as Intentional than as Physical

Therefore, since the act of the intellect as an intentional quality disregards the laws of other qualities and proceeds in a far subtler way, there is no reason why it could not divide intentionally even an object physically undivided in itself, for it possesses unlimited strength to represent. Therefore, since by this reason it can represent an object that is not at all, it can represent inadequately what is.

The duality of ratios in the act of the intellect will be clearly discerned in this example: let us suppose that a soul existing here in a body elicits a prescinding intellectual act about itself, conceiving only the ratio of soul, and not the individual difference. This intellectual act, inasmuch as it is intentional, terminates only at the ratio of soul, not at the individual difference, and thus it separates these ratios from each other in the mind. Still, inasmuch as it is a physical quality, it makes no distinction between those ratios, but is equally inherent to either, since, physically and on the part of the thing, they are not two ratios, but one, under which the said act of the intellect does no more divide the ratio of soul from the individual difference than the whiteness in the wall divides the ratio of the wall as such from the ratio of a particular wall. And the reason is clear: since the physical intellectual act is inherent to the soul as to a subject and physically, any division it could make would be physical, which is contradictory, as it would imply being and not being the same thing physically.

For a thing to be on the one hand physically and really the same, on the other intentionally distinct or divided, is no contradiction. This only implies that the thing is not adequately known on the part of the object, or not whole at once, but is placed before the mind by steps, and as it were by parts, and thus represented according to diverse ratios, which, albeit they are the same on the part of reality and consist in the same physical entity, nonetheless the intellect with its shrewdness can perceive one without perceiving the others, which is to divide precisively or to distinguish objectively.

Two Aquinas Passages on the Duality of Intellective Ratios

First Passage

“What is joined in reality the intellect can at times receive separately, when one of the elements is not enclosed in the notion of the other. Thus, in the number three the intellect can consider the number two only, and in the rational animal it can consider what is sensible only”. (Contra Gentiles I, ch. 54, nº 3.)

Second passage

“Now our soul possesses two cognitive powers; one is the act of a corporeal organ, which naturally knows things existing in individual matter; hence sense knows only the singular. But there is another kind of cognitive power in the soul, called the intellect; and this is not the act of any corporeal organ. Wherefore the intellect naturally knows natures which exist only in individual matter; not as they are in such individual matter, but according as they are abstracted therefrom by the considering act of the intellect; hence it follows that through the intellect we can understand these objects as universal; and this is beyond the power of the sense. Now the angelic intellect naturally knows natures that are not in matter; but this is beyond the power of the intellect of our soul in the state of its present life, united as it is to the body. It follows therefore that to know self-subsistent being is natural to the divine intellect alone; and this is beyond the natural power of any created intellect; for no creature is its own existence, forasmuch as its existence is participated. Therefore the created intellect cannot see the essence of God, unless God by His grace unites Himself to the created intellect, as an object made intelligible to it”. (Summa th., I, q. 12 a. 4 co.)

Mode of Existence of Distinctions on the Part of the Object

To begin with, anyone intending to produce a real or physical change in the object by the act of the intellect that distinguishes objectively, is doomed to failure: to my knowledge, no author teaches so.

Argument from Nominalists

The object as adequately distinct from cognition was first undistinguished and undivided; therefore, if cognition distinguishes it, cognition places or produces in it something intrinsic by which it may be distinguished, which is totally unintelligible.


Prior to cognition, the object was distinct fundamentally: that a cognition can divide an object and that an object can be divided by a cognition, are correlatives. Yet I deny that any distinction is placed or produced in the object by the intellectual act. You might urge, “Therefore, there is absolutely no actual distinction on the part of the object, and this is evident, as earlier it was not, as we admit, and the intellect does not make it; therefore, there is none of it”. I distinguish the minor premise: that the intellect does not make it positively, I grant; that the intellect does not make it precisively, I deny. in other words: that the intellect makes nothing by introducing anything in the object, I grant, that the intellect makes nothing by subtracting something from the object, I deny. Indeed, when it conceives the principle of feeling without conceiving the rational, it subtracts precisively the principle of reasoning from the principle of feeling, which, in order to this intellectual act, happens as if it were not really identified with the principle of feeling on the part of the thing. in other words, the intellectual act subtracts it not physically but intentionally, not positively—or rather negatively by conceiving it as not united with the principle of feeling, against the Aristotelian principle, “The work of abstracting is not a lie”—but precisively, i. e., not conceiving that with which it is conjoined on the part of the thing.

The thing will become most clear by this example. Let us suppose that the intellect first represents a wall with no color and then represents whiteness inherent to it. Now the wall behaves intrinsically otherwise than before with respect to the intellect, as now the intellect can form propositions it could not form before about the wall and move the will to various acts to be exercised about it. The same holds true of division or separation. Let an intellect conceive Peter without sight or the sun without light: truly, with respect to the intellect, sight is divided from Peter and light from the sun, and now they behave otherwise with respect to the intellect than when the latter was represented with light and the former with sight.

Nominalist Self-Defense

The act of the intellect is extrinsic to the object; therefore it can make no intrinsic difference in it.


I distinguish the consequent: That the intellect cannot make in the object an intrinsic difference immediately by itself, I grant; that it cannot make in it an intrinsic difference mediately or by the term that it intentionally attaches to the object or removes from it, I deny. By way of example, according as I represent a wall with or without whiteness, the wall behaves intrinsically objectively otherwise, not by an act of the intellect immediately, but by the whiteness that the intellect intentionally attaches to the wall or removes from it. Even as there will be no more whiteness in the wall physically if God withdraws his physical concourse, so will whiteness cease to be in the wall intentionally or with respect to the intellect if this withdraws its intentional concourse or ceases to represent it.

This division on the part of the object is made by an act of the intellect in the genus of a defective formal cause, for the act that performs it involves necessarily two parts: the positive representation of one predicate, say, animal, and the negation of the representation of the other, ipso facto removed precisively from the object. Thence it follows that, although rational is physically and really identified with object, yet here and now, with respect to the intellect, it is as if it were not identified with it. Further, even if rational were rendered impossible, the act of the intellect would persist in the same way if the predicate animal remained possible.

Now, whether it should be said that an intentionally divided object is divided intrinsically, is a matter of words. If the object is taken causatively or is referred to a dividing cause, it is false, because the negation of the act of the intellect is as extrinsic to the object as the act representing another predicate, both of which constituting the whole cause of this division. Instead, if it is taken objectively, i. e., if it is referred to the divided extremes themselves, the object can be said to be intrinsically divided and distinct, because something intrinsic to it is truly removed from it, namely its constitutive difference: and what is more intrinsic to a thing than its difference, which is part of its essence? Anyone who would say that something intrinsic to the object is extrinsically removed by a prescinding act, would speak most properly.

To a clearer understanding of this distinction between predicates, it may be asked: when someone distinguishes and divides the animal from the rational in man by a prescinding act, would an angel see any change, distinction or division in the object? I answer: if the angel intuits the man or divided object immediately, he will see no change in it, even as he would see none if he intuited Peter when someone represented him without an arm, for an angel’s knowledge is directed to objects as they are on the part of the thing, not as they underlie our concepts. But if the angel intuits the prescinding act, he will only know the object inadequately, because he knows it by the known means, and hence by this act of his he knows no more than the prescinding act shows to him: but it only shows animal, therefore the angel will know only that and thus will have his knowledge equally limited as man’s. Therefore the act of an angel with respect to the act of prescinding man is intuitive and immediate; with respect to the prescinded object, it is abstract and mediate.

Therefore, to prescind or to know only animal, is to know animal without rational, with the negation taking place on the part of the intellect, not of the object, because when only animal is known the sense the sense is not that both animal and the negation of rational are known. For example, when someone is said to have seen or killed only Peter, the sense is not that he saw or killed as well Peter as the negation of Paul with all other negations of things, but that he saw or killed none but Peter. in the negative precision the negation takes place on the part of the object, as in the proposition, “the animal is not rational”, or when the negation of animal is conjoined with the negation of rational.

Arguments are Solved which Can Peculiarly Arise
from this Way of Explaining Distinctions

First Objection

If animal is prescinded from rational by an inadequately knowing act, rational will be prescinded from animal by the same operation: but it is not prescinded. The conclusion is patent. The minor premise is proved: as we suppose, rationality is unknown there.


In that case rational is prescinded from animal only negatively, or it is not known to be united.

Second Objection from Father Hurtado

The distinction is an extrinsic form given to the object; therefore, where the object is one, the form cannot be given but to one, much less make any intrinsic distinction in it. 


The act of the intellect inasmuch as it is an intentional quality, makes an intrinsic intentional distinction in the object, not by placing anything, but by removing, and thus, as an intentional quality, it can divide what is united and be intentionally given to one object that is distinct by the very fact that the intellect tends to it inadequately, or into one part of it and not into another. The a priori reason has been assigned above, because the intellect without species is per se no complete principle of knowledge; therefore, since it gets species abstracted from the sole operations of feeling, it will not know the principle of reasoning at all.

The immediate reason why one object is known and not another, is because the intellect is provided with this and not another species, or because it will use this and not another. The mediate reason revolves to the object itself that has the species represent it and that produces the species in order to elicit the intellectual act by which it may be known. Hence it exacts that the object be known in the very manner in which it produces the instrument of this cognition, namely its species; but it produces it inadequately; therefore it is its requirement and its capacity to be known inadequately. If anyone were to retort that species are produced by God, it should be answered that God as the author of nature operates according to the exigencies of things and introduces such species as the object exacts: he concurs by a particular action, one in species or number, because the effect requires that action which is one in species or number.

Third Objection

The object terminates what is on the part of thing, but that is indivisible, therefore the object terminates the whole of it, because on the part of the object, there exists no more than one something.


The minor premise is distinguished: that the object is indivisible physically, is granted; intentionally, it is denied. For even as the intellect as an intentional agent respects the object and can divide it, so, conversely, the object respects the intellect and produces an inadequate species of itself.

Fourth Objection

The real entity of the object terminates, but the real entity is not divided, therefore the whole of it terminates and is known; therefore no division is made.


The major premise is distinguished: that the real entity terminates adequately and according to whole of itself, is denied; inadequately, is granted. Indeed, the real entity terminates the object for the exigency of the act not as a physical but as an intentional quality: and, as such, the act of the intellect proceeds in a far different way than as a physical form. The minor premise is likewise distinguished: that the real entity of the object is not divided physically, is granted; that it is not divided intentionally, is denied: otherwise, in what way would there be any metaphysical composition if there were no distinction on the part of the object? Indeed, although this composition is made formally by an act of the intellect, yet it is the object that is composed, which could by no reason be composed of metaphysical parts unless, earlier, at least by some act, those parts were distinguished and divided.

Fifth Objection

Either the whole reality that is on the part of the thing terminates and is known when the animal is known, or not: if yes, then there is neither division nor distinction; if not, then some reality remains to be known, therefore there are two realities, namely the known reality and the unknown reality.


Intentionally, there are two things if the reality only sounds as a real predicate, but in fact something else sounds, namely, the existence of two really distinct realities. Therefore, no duplicity of realities is there, but the same reality is known inadequately and is divided by the intellect into two formalities or predicates, and thus they are formally distinct.

Philosophia Universa