PROPOSITION LVIII.

The real intrinsic principle of Formal or Universal Unity is the essential nature of the individual Entity.

In consonance with the doctrine just enunciated, the present Thesis primarily regards Species, Genus, and Difference. But it must not be supposed that it applies only to these three classes of Universals. For, though in regard of Substance which they inform, Property and Accident are obviously unessential, forasmuch as neither of them belongs to the essence of Substance; nevertheless, they have, each and all of them, an essence of their own, without which they could neither lay claim to the character of true Universals, nor be capable of definition. Albeit, therefore, they have so intimate a transcendental relation to substance, that this latter is necessarily included in their definition; still, they have a nature of their own, into which substance does not enter, that secures for them a place within the sphere of Metaphysics. Their conceptual relation to the subject of predication is logical; their actual relation to the subject of inhesion is mainly physical. But the essential nature of their transcendental relation to substance and of their own respective modifications of this latter, considered in themselves, belong exclusively to the metaphysician. Accordingly, the truth expressed in the above Proposition is applicable likewise to the last two classes of Universals; as will be seen.

THE PROOF of this Thesis rests upon the following Premiss There is no real distinction of any sort between the Genus, Difference, and Species, considered objectively in one and the same individual. Such, to begin with, is the teaching of the Angelic Doctor. In the first part of his Summa he proposes an objection to his statement, that Angels are specifically distinguished from each other; and the objection is, that since Difference is nobler than Genus, whatever Entities are alike in regard of that which is noblest in their Nature, must be alike in their ultimate Difference. But the Angels are alike in Intelligence, which is the noblest element of their Nature. Therefore they cannot be specifically distinguished. To this difficulty St. Thomas makes the following answer : -- ' Difference is nobler than Genus, as the determinate is nobler than the undetermined, -- as that which is proper, than that which is common; but not as though they were two different Natures. Otherwise, we should have to admit that all irrational animals are of one Species; or else, that there is in them some other Form more perfect than the sensitive Soul. As, then, irrational animals differ according to differing determinate grades of sensitive Nature; so Angels specifically differ according to different grades of intellectual Nature.'^{1} The whole argument, if carefully weighed, affords a very cogent confirmation of the Premiss proposed; but notice, in particular, the assertion of the Angelic Doctor, that Genus and Difference do not differ, as though they were two Natures really distinct, but only as the undetermined and common differ from the determined and special. There is one element in the proof, which may seem to be wanting. At least, it is not explicitly stated in the passage. It is necessary to show that St. Thomas, in speaking of the determined and undetermined, is referring to the determination and indetermination of the objective concept, not of a determination or indetermination physically discoverable in the entities themselves as individual and existent. But this is fully and explicitly supplied in another place, where he is engaged in proving that there is but one soul in man. To this Proposition he objects, that Genus is assumed from the Matter, Difference from the Form. But Rational, which is the Difference of man, is derived from the intellectual soul; whereas Animal, which is his Genus, stands fbr body animated by a sensitive soul. Therefore, the intellectual soul in man stands, to his sensitive soul, in the relation of Form to Matter. Consequently the two cannot he the same; for the former presupposes the latter, as the Matter which supports it. St. Thomas replies: -- 'We must not suppose that there is a diversity in the things of nature exactly corresponding with the different concepts and representations of the mind, which follow from the way in which the intellect regards its object; because the Reason can apprehend one and the same thing in different ways. Thus, because the intellectual soul virtually contains that which is in the sensitive soul, and more besides; the Reason can consider separately that which appertains to the faculty of the sensitive soul, as something, in a way, imperfect and material' (because potential or capable of act). 'And, forasmuch as it discovers that this is common to man with other animals, it thence forms the concept of Genus; while it takes that wherein the intellectual soul is in excess of the sensitive, as that which is formal and completive, and thence forms the idea of the Difference of man.'^{2} Evidently, therefore, the Angel of the Schools does not consider that there is any real distinction between the Species, Difference and Genus in the same Nature; but attributes the distinction exclusively to the operation of the intellect. He teaches the same doctrine, as in other places, so particularly in the latter half of his thirtieth Opusculum de Ente et Essentia. It remains to confirm this fundamental Premiss by reason.

i. The first Argument is derived from the doctrine of individuation, as it has been already established in the preceding Article. For, in one and the same individual, it is the same individual Difference which determines the ultimate Species and, together with it and by means of it, all the other higher and more general grades of Being. Thus, the individual Difference of Henry, e.g. not only determines Henry to be this man, but also to be this animal, this living thing, this substance; and it is the same identical this throughout. Now, it has been seen that the Haecceity of an individual is not really distinct from the specific nature. Wherefore, it is not distinguished really from the other superior grades of Being; and, consequently, those superior grades of Being cannot really differ either from one another or from the specific Nature. Hence, Substance, Living Being, Animality, Human Nature, are in Henry one reality, represented by different concepts. Nor can it be doubted that the same individual Difference does determine the superior grades together with, and by means of, the ultimate Species. For the Genera, down to the last of the subaltern Species, are in a state of essential potentiality or indetermination, and require determination by a specific Difference. Till that indifference or indetermination is resolved, no one of them is proximately capable of individuation. An animal, as such, is incapable of individuation or of existence. It must first be determined to he a rational, or an irrational, animal. Moreover, the individual Difference determines all the superior grades. There can be no skipping. As, then, there is an essential order in the Differences, from the widest generic down to the specific; so is there in like manner between the generic, specific, and individual Difference. Accordingly, if Body cannot be determined to Animal, save through the medium of Living Being; so neither can Animal (the Genus) be determined to the individual Henry, save through the medium of the specific Difference, Rational. Hence, it is plain that the individual Difference proximately determines the Species, and, in and by this latter, the Genera.

ii. The second argument is founded on the Unity of the intrinsic physical principle by which the individual, e.g. Henry, is formally constituted. For the one simple soul of Henry is at once the unique principle of growth, sensation, thought. Wherefore, by it he is at once a living Being, an animal, and a man. As, then, there are not in Henry three souls, -- one vegetative, another animal, a third rational, -- but one soul, virtually equivalent to these three; in like manner, these three grades of Being, Life, Animal, Man, are not really distinct. The Haecceity of the last individuates the other two, at the same time with, and by means of, the last.

iii. It stands to common sense that an animal e.g. cannot be individuated, or be proximately capable of existence; till it is determined whether such animal is to be a brute or a man. Who could conceive of a body coming into existence, which is indifferent as to whether it shall be living or inanimate? But its relation to existence is the measure of its reality. Therefore, its reality is determined by, and depends upon, its ulterior and specific determination. If so, it has no reality, apart from the specific determination; and, consequently, its reality cannot be really distinct from that of the ultimate Species.

iv. The last argument is a priori, and it is this. There is no need of any real distinction in these graduated successions of Being; therefore, any such distinction is to be rejected. For the multiplication of real distinctions without sufficient reason is contrary to the principles of sound philosophy. There is no need of any real distinction; because we can sufficiently account for these Universals by the nature of the object and the abstractive faculty of the intellect, without supposing really distinct Forms in the object itself. There are, (as is patent even to the superficial ohserver), in every real Being, a certain number of essential notes which together compose its Nature. Some of these notes have a complete similarity with notes to he found in other specific Natures; and, of this latter class of notes, there are some which have a wider and more general similarity; till at last we arrive at a note or notes, which are, as it were, common, by virtue of their similarity to all things that either exist or can possibly exist. On the other band, there are notes of dissimilarity, which grow in number and variety, in proportion as we approach nearer to the distinctive limits of the specific Nature; so that notes that are similar to those of cognate classes of Being, are dissimilar from those of more remote classes; while notes that are dissimilar from those of even cognate classes, and are, consequently, called specific, augment in dissimilarity from others, as the sphere of comparison widens. Thus the whole creation is entitatively linked together, yet pours itself forth in an endless variety. If we transcend the limits of essence or the specific Nature; there appear, over and above, individual notes, which distinguish entities within the same Species from each other, and are proper to one existing individual, and to no other. But here it is necessary to interpose a caution. It must not be imagined that these notes, as they are wisely and characteristically called, are like so many separate notes of music, produced distinctly one after the other. On the contrary, they are, as it were, a full chord. These elements in a given nature are truly notes, i.e. real elements of Being, by which the Nature is known. They are its manifestation; in themselves absolutely, the Nature itself. Thus they are one, and they are many; but their multiplicity is virtual, their unity is actual. They are known as many; they exist as one. There is a virtual equivalence in the things that together compose the Universe, which increases in proportion as we ascend in the scale of Being. Organized Matter has virtually in itself all that there is of reality in unorganized Matter, and much more besides. Animal life contains virtually within itself all that is positive in vegetable life, and much more besides; as rational life contains virtually within itself all the reality of animal, and consequently of vegetable, life, with the addition of much that is peculiar to itself. But these realities are only equivalently and virtually there; not in their own distinct and independent Unity. Created Being is not composed of essential parts essentially distinct, which are stitched together with needle and thread. It is a facultative evolution, -- a centre of forces, as some moderns would express it; but it is the evolution of unity. Thus, to repeat the illustration of St. Thomas, the human soul is to man principle of nutrition, sensation, thought; so that it is virtually equivalent to three souls. It actually does the work of three. Yet, in itself, it is devoid of all physical composition, and is simply, indivisibly, one. Care must, however, here be taken to avoid the error of confounding the metaphysical with the physical consideration of a specific Nature. In the case of all entities that are in any sense material, physical composition of distinct parts is a simple necessity of their Nature. Hence, if we define man physically, it would be said that he is a living body, composed of flesh, bones, blood, nerves, limbs, &c., which is animated by a rational soul. But what is his metaphysical definition? He is a rational animal. Now here, the animal in man is not something entitatively distinct from the rational; for this latter includes in man all the reality of animal, together with something additional of its own.

So far for the object. On the other hand, the intellect, by virtue of its abstractive power, can seize upon a certain phase of this specific Unity, and neglect the rest; in other words, it may intend to conceive, and represent in its concept, certain notes of a specific Nature to the non-inclusion of the others. Thus, to continue the illustration of St. Thomas, it may represent to itself only the nutritive and sensitive characteristics of the soul, and so conceive the Genus, Animal; or it may confine itself to the one distinguishing characteristic of Intellect, and thus conceive the Difference, Rational. The experience of every day assures us that our minds have, and constantly use, this power of abstraction.

But it is plain that this fecundity on the part of the object and this abstractive power of the human intellect, are together sufficient to account for formal or universal Unity, without supposing that the essential attributes are really distinguished from each other in one and the same individual.

It may not be amiss to illustrate this somewhat abstract doctrine by an example. Suppose two men, William and James. There are evidently certain characteristics of their nature, in which they are exactly similar to each other; others, again, in which one is manifestly distinguishable from his fellow. These latter constitute the individual Difference; the former, in their entirety, the specific Nature. If I assume those notes which together constitute the specific nature, and compare them with the nature of a dog; again I find certain notes of agreement or similarity between the two, certain other notes of disagreement. If I represent to myself the former only, I form the generic concept of animal. By a similar process of thought, I compare this idea with the essential notes of a geranium, and, assuming once more the notes of similarity alone, I arrive at the concept of life. Yet again, I compare this new idea with the characteristics of a diamond, and, by virtue of the notes that are similar in each, I at length arrive at the summum Genus, Substance. Now, it has been already shown that the specific Nature in any given man does not really differ from his individual Difference or Haecceity; so that the notes in William which are similar to those in James are not really and objectively distinct, as being in William, from those other notes by which he is distinguished from James. Surely, it is only reasonable to conclude, that the same law holds good throughout the whole chain of abstraction.

Once more: Even between the Creator and the creature there are points of similarity and points of difference. That there. are points of difference, may be taken for granted. Let us take one point of similarity, where the illustration is most clear. God is Being; the creature is Being; in this, then, they are similar. Yet this note, on the one hand, cannot in God be really distinct from other notes in His Nature; because, by reason of His supereminent Perfection, He is infinitely simple and free from all, even metaphysical, composition. Neither, on the other hand, can this note be really distinct from the other notes of the creature; for, whatever these notes may be, they either must be Being or they are nothing. From these examples, therefore, the conclusion inevitably follows, that the same identical reality may be the principle of similarity with, and dissimilarity from, the same others, without there being the smallest real distinction within the reality itself.

On the strength of the metaphysical principle thus demonstratively established, it will be easy to prove the truth of the present Proposition. For all Universals, whether absolute or relative, are concepts of the essential attributes of Being. Since, then, absolute Universals are representative of formal, and relative Universals, of universal, Unity; it follows, that the essential attributes (which are the one real object of those concepts), are the real, intrinsic, principle of these two unities. For the essential Attributes, as they are called, are only different modes of conceiving one and the same Nature.

The proof is plain enough as touching Species, Difference, and Genus; for these three confessedly fall within the sphere of Essence. But it is by no means so plain as regards Property and Accident, which are, as confessedly, outside the sphere of Essence. It cannot, indeed, be denied that the essential nature of their Subject, in their relation to which they have received their logical names of Property and Accident, is not the real intrinsic principle of their formal or universal Unity. But have they no essential Nature of their own? If not; how is it that out of the ten Summa Genera, nine belong to Accidents? It will be as well to interpose here, that in Metaphysics Accident includes Property as well as Accident specifically so called, and expresses everything real in the individual Entity which is not included in its Essence. To resume: As Accident has its own real Entity really distinct from its substantial Subject. It has its own Essential Nature; and this Essential Nature is the real, intrinsic, principle of formal or universal Unity to those Universals which the human intellect forms, in regard of Accidents, by its process of abstractive thought. Moreover, it will be found that, as in the instance of substance, such and such Accidents exhibit essential notes, some of which are similar to, others dissimilar from, the essential notes of other classes of Accidents. Thus, to take an instance: Colour, we are told, is a corporal, qualitative, Accident, by which the rays of white light that impinge on bodies, are so modified as to produce in the soul sensations of red, yellow, blue, &c. Now, compare this Accident with cold. Both exist in bodies; both produce sensations in the soul; both affect the quality of substance. So far they are alike. But one affects the sense of sight; the other, the sense of touch. In this they are dissimilar. Again, compare colour with virtue. They are both Accidents; for they come and go, while their Subject remains essentially the same. They are both Qualities. Thus much of similarity there is between them. But the former affects the body; the other, the soul. The one is the result of natural law; the other, the result of human free-will. In these respects they differ. Lastly, compare colour with size. There is one point of similarity, in that both are Accidents; but for the rest, they differ. You are, in fact, in presence of two Categories, the one of Quality, the other of Quantity. But who could ever imagine that the capacity of exciting the sense of sight, or the inherence in bodily substance, or any non-essential property of colour, is something really distinct from its specific Nature? Thus the truth of the Proposition is confirmed, even in the case of Accidents.

There is, however, one difficulty, touching this matter, which demands solution. For, assuming the doctrine which has just been developed to be true, there seems no reason for asserting any difference in the application of the truth, enunciated in the present Thesis, to Substance and to Accident respectively. Yet, in the introduction to the proof, it was stated that the Proposition primarily applied to Substance. For Genus, Difference, and Species, in the logical Predicables belong, as is obvious, to Substance; at least, primarily. The last modifying clause is added, because Accidents have likewise their Genus, Difference, and Species; and there may, too, be Accidents of Accidents, as e.g. more or less in Qualities. Wherefore, the reason why such distinction has been introduced, is this. Substance enters into the definition of Accident. If Accident is considered in the concrete, it enters in recto (as Logicians say), i.e. in the nominative case; for instance, cold meat, virtuous man, &c. If Accident is assumed in the abstract, it at least virtually enters in obliquo, i.e. in some indirect case other than the Nominative; for instance, coldness of ice, the virtue of Socrates. For, even if the Subject is not expressed, it is understood; since virtue cannot really exist save in man, and coldness cannot naturally exist save in corporal substance. Hence, Accident is not simply Being, -- but is Being of Being; that is, in other words, it essentially includes, within its nature, a transcendental relation to the Subject which it has an aptitude for informing. Accordingly, though it has an Essence of its own, really distinct from the Essence of its Subject; yet, that Essence includes a transcendental relation to the Subject, however the latter may be conceived. This accords with the old adage, that when Socrates was born, all the Categories were born with him. Such is the explanation of the distinction that has been made.

{1} 'Ad primum ergo dicendum, quod differentia est nobilior genere sicut determinatum indeterminato et proprium communi, non autem sicut alia et alia natura. Alioquin oporteret quod omnia animalia irrationalia essent unius speciei; vel quod esset in eis aliqua alia perfectior forma quam anima sensibilis. Differunt ergo specie animalia irrationalia secundum diversos gradus determinatos naturae sensitivae, et similiter omnes Angeli differunt specie secundum diversos gradus naturae intellectivae.' 1ae 1, 4, ad 1m.

{2} 'Ad quartum dicendum, quod non oportet secundum diversas rationes vel intentiones logicas, quae consequuntur modum intelligendi, diversitatem in rebus naturalibus accipere; quia ratio unum et idem secundum diversos modos apprehendere potest. Quia igitur, ut dictum est in corp. art., anima intellectiva virtute continet id quod sensitiva habet et adhuc amplius, potest seorsim ratio considerare quod pertinet ad virtutem sensitivae, quasi quoddam imperfectum et materiale. Et quia hoc invenit commune homini et aliis animalibus, ex hoc rationem generis format. Id vero in quo anima intellectiva sensitivam excedit, accipit quasi formale et completivum; et ex eo format differentiam hominis.' 1ae lxxvi, 3, ad 4m.