The most divergent views have prevailed among philosophers [pg 208] both as to what a category is or signifies, and as to what or how many the really ultimate categories are. Is a category, such as substance, or quality, or quantity, a mode of real being revealed to the knowing mind, as most ancient and medieval philosophers thought, with Aristotle and St. Thomas? or is it a mental mode imposed on reality by the knowing mind, as many modern philosophers have thought, with Kant and after him? It is for the Theory of Knowledge to examine this alternative; nor shall we discuss it here except very incidentally: for we shall assume as true the broad affirmative answer to the first alternative. That is to say, we shall hold that the mind is able to see, in the categories generally, modes of reality; rejecting the sceptical conclusions of Kantism in regard to the power of the Speculative Reason, and the principles which lead to such conclusions.
As to the number and classification of the ultimate categories, this is obviously a question which cannot be settled a priori by any such purely deductive analysis of the concept of being as Hegel seems to have attempted; but only a posteriori, i.e. by an analysis of experience in its broadest sense as including Matter and Spirit, Nature and Mind, Object and Subject of Thought, and even the Process of Thought itself. Moreover it is not surprising that with the progress of philosophical reflection, certain categories should have been studied more deeply at certain epochs than ever previously, that they should have been “discovered” so to speak, not of course in the sense that the human mind had not been previously in possession of them, but in the sense that because of closer study they furnished the mind with a richer and fuller power of “explaining” things. It is natural, too, that historians of philosophy, intent on tracing the movement of philosophic thought, should be inclined to over-emphasize the relativity of the categories, as regards their “explaining” value—their relativity to the general mentality of a certain epoch or period.[216] But there is danger here of confounding certain large hypothetical conceptions, which are found to yield valuable results at a certain stage in the progress of the sciences,[217] with the categories proper of real being. If the mind of man is of the same nature in all men, if it contemplates the same universe, if it is capable of reaching truth about this universe—real truth which is immutable,—then the modes of being which it [pg 209] apprehends in the universe, and by conceiving which it interprets the latter, must be in the universe as known, and must be there immutably. Nowhere do we find this more clearly illustrated than in the futility of the numerous attempts of modern philosophers to deny the reality of the category of substance, and to give an intelligible interpretation of experience without the aid of this category. We shall see that as a matter of fact it is impossible to deny in thought the reality of substance, or to think at all without it, however philosophers may have denied it in language,—or thought that they denied it when they only rejected some erroneous or indefensible meaning of the term.
60. The Aristotelian Categories.—The first palpable distinction we observe in the data of experience is that between substance and accident. “We might naturally ask,” writes Aristotle,[218] “whether what is signified by such terms as walking, sitting, feeling well, is a being (or reality).... And we might be inclined to doubt it, for no single one of such acts exists by itself (καθ᾽ αὐτὸ πεφυκός), no one of them is separable from substance (οὐσία); it is rather to him who walks, or sits, or feels well, that we give the name of being. That which is a being in the primary meaning of this term, a being simply and absolutely, and not merely a being in a certain sense, or with a qualification, is substance—ὡστε τὸ πρώτως ὂν καὶ οὐ τὶ ὂν ἀλλ᾽ ὂν ἁπλῶς ἡ οὐσία ἂν εἴν.”[219] But manifestly, though substances, or what in ordinary language we call “persons” and “things”—men, animals, plants, minerals—are real beings in the fullest sense, nevertheless sitting, walking, thinking, willing, and actions generally, are also undoubtedly realities; so too are states and qualities; and shape, size, posture, etc. And yet we do not find any of these latter actually existing in themselves like substances, but only dependently on substances—on “persons” or “things” that think or walk or act, or are large or small, hot or cold, or have some shape or quality. They are all accidents, in contradistinction to substance.
It is far easier to distinguish between accidents and substance than to give an exhaustive list of the ultimate and irreducible classes of the former. Aristotle enumerates nine: Quantity (ποσόν), Quality (ποῖον), Relation (πρὸς τι), Action (ποιέιν), [pg 210] Passion (πάσχειν), Where (ποῦ), When (ποτέ), Posture (κεῖσθαι), External Condition or State (ἔχειν). Much has been said for and against the exhaustive character of this classification. Scholastics generally have defended and adopted it. St. Thomas gives the following reasoned analysis of it:[220] Since accidents may be distinguished by their relations to substance, we see that some affect substances intrinsically, others extrinsically; and in the former case, either absolutely or relatively: if relatively we have the category of relation; if absolutely we have either quantity or quality according as the accident affects the substance by reason of the matter, or the form, of the latter. What affects and denominates a substance extrinsically does so either as a cause, or as a measure, or otherwise. If as a cause, the substance is either suffering action, or acting itself; if as a measure, it denominates the subject as in time, or in place, or in regard to the relative position of its parts, its posture, in the place which it occupies. Finally, if the accident affects the substance extrinsically, though not as cause or as measure, but only as characterizing its external condition and immediate surroundings, as when we describe a man as clothed or armed, we have the category of condition.
It might be said that all this is more ingenious than convincing; but it is easier to criticize Aristotle's list than to suggest a better one. In addition to what we have said of it elsewhere,[221] a few remarks will be sufficient in the present context.
Some of the categories, as being of lesser importance, we may treat incidentally when dealing with the more important ones. Ubi, Quando, and Situs, together with the analysis of our notions of Space and Time, fall naturally into the general doctrine of Quantity. The final category, ἔχειν, however interpreted,[222] may be referred to Quality, Quantity, or Relation.
A more serious point for consideration is the fact, generally admitted by scholastics,[223] that one and the same real accident may belong to different categories if we regard it from different standpoints. Actio and passio are one and the same motus or change, regarded in relation to the agent and to the effect, respectively. Place, in regard to the located body belongs to the category ubi, whereabouts; in regard to the locating body it is an aspect of the latter's quantity. Relation, as we shall see, is probably not an [pg 211] entity really distinct from its foundation—quality, quantity, or causality. The reason alleged for this partial absence of real distinction between the Aristotelian categories is that they were thought out primarily from a logical point of view—that of predication.[224] And the reason is a satisfactory one, for real distinction is not necessary for diversity of predication. Then, where they are not really distinct entities these categories are at least aspects so fundamentally distinct and mutually irreducible that each of them is indeed a summum genus immediately under the concept of being in general.
It seems a bold claim to make for any scheme of categories, that it exhausts all the known modes of reality. We often experience objects of thought which seem at first sight incapable of reduction to any of Aristotle's suprema genera. But more mature reflection will always enable us to find a place for them. In order that any extrinsic denomination of a substance constitute a category distinct from those enumerated, it must affect the substance in some real way distinct from any of those nine; and it must moreover be not a mere complex or aggregate of two or more of the latter. Hence denominations which objects derive from the fact that they are terms of mental activities which are really immanent, actiones “intentionales,”—denominations such as “being known,” “being loved,”—neither belong to the category of “passio” proper, nor do they constitute any distinct category. They are entia rationis, logical relations. Again, while efficient causation resolves itself into the categories of actio and passio, the causation of final, formal and material causes cannot be referred to these categories, but neither does it constitute any new category. The influence of a final cause consists in nothing more than its being a good which is the term of appetite or desire. The causation of the formal cause consists in its formally constituting the effect: it is always either a substantial or an accidental form, and so must be referred to the categories of substance, or quality, or quantity. Similarly material causality consists in this that the matter is a partial constitutive principle of the composite being; and it therefore [pg 212] refers us to the category of substance. It may be noted, too, that the ontological principles of a composite being—such as primal matter and substantial form—since they are themselves not properly “beings,” but only “principles of being,” are said to belong each to its proper category, not formally but only referentially, not formaliter but only reductivé. Finally, the various properties that are assigned to certain accidents themselves are either logical relations (such as “not having a contrary” or “being a measure”), or real relations, or intrinsic modes of the accident itself (as when a quality is said to have a certain “intensity”); but in all cases where they are not mere logical entities they will be found to come under one or other of the Aristotelian categories.
The “real being” which is thus “determined” into the supreme modes or categories of substance and accidents is, of course, “being” considered substantially as essential (whether possible or actual), and not merely being that is actually existent, existential being, in the participial sense. Furthermore, it is primarily finite or created being that is so determined. The Infinite Being is above the categories, super-substantial. It is because substance is the most perfect of the categories, and because the Infinite Being verifies in Himself in an incomprehensibly perfect manner all the perfections of substance, that we speak of Him as a substance: remembering always that these essentially finite human concepts are to be predicated of Him only analogically ([2], [5]).
It may be inquired whether “accident” is a genus which should be predicated univocally of the nine Aristotelian categories as species? or is the concept of “accident” only analogical, so that these nine categories would be each a summum genus in the strict sense, i.e. an ultimate and immediate determination of the concept of “being” itself? We have seen already that the concept of “being” as applied to “substance” and “accident” is analogical ([2]). So, too, it is analogical as applied to the various categories of accidents. For the characteristic note of “accident,” that of “affecting, inhering in” a subject, can scarcely be said to be verified “in the same way,” “univocally,” of the various kinds of accidents; it is therefore more probably correct not to regard “accident” as a genus proper, but to conceive each kind of accident as a summum genus coming immediately under the transcendental concept of “being”.