CATEGORY. - Originally it was the ‘accusation’, that is, the judicial action opposed to ‘apology’, according to Aristotle (*Rhet.*, I, 3, 1358 b 11), who seems to have been the first to use the term ‘c.’ in a strictly philosophical sense, making it the subject of the first treatise of the *Organon*. The *categories* are the meanings that the terms of judgment have when used alone ‘without any synthesis’, such as ‘man’, ‘horse’, ‘runs’, ‘wins’; they are therefore the most characteristic ‘indications and determinations’ of language, thought, and reality: not exclusively ‘predicates’, because Aristotle includes among the categories, and indeed places first, the individual substance, that is, the ultimate subject (*Met.*, IX, 1, 1042 a 26). Indeed, Boethius rendered the Greek term not with *predicatum* but with *praedicamentum*, which is what in some way enters into a predication either as subject or as predicate; it is therefore futile to criticize, as some moderns do (N. Hartmann), the Aristotelian notion by alleging that not all categories are ‘predicates’. According to David the Armenian, the categories are the meanings of ‘first position’ (*Scholia*, 29 b 21), such as: substance, quantity, quality, relation, action, passion, place, time, position, and habit. But it does not seem to be a fixed number, since while the earlier works give the complete list (*Cat.*, 4, 1 b 25; *Top.*, I, 9, 103 b 20), the more mature works give variable lists ranging from a maximum of eight (*Met.*, XII, 12, 1068 a 8) down to six, five, four, or even only three (v. H. Bonitz, *Index Ar.*, 378 a 49 ff). Nor is the order constant, except for substance, which always holds the place of honor. Hence also the root or pretext of the bitter controversies that have troubled Aristotelians of every age. First of all, the question arises whether the list of categories is to be taken as a classification of mere words, *φωναί* (Alexander of Aphrodisias, Eustathius, and the nominalists), or of mere concepts, *νοήματα* (Herminus, conceptualists), or of mere things, *πράγματα* (Plotinus, Porphyry, the Stoics, the ontologists). David, to whom we owe this account (*Scholia*, 28 b 7 ff.), prudently sees the three solutions as integral moments of a single interpretation that adequately renders the nature and fullness of Aristotelian realism: the categories are ‘simple words which signify simple realities by means of simple concepts’ (*op. cit.*, 29 b 25). Trendelenburg, while acknowledging the metaphysical meaning, maintained that the primary derivation of the Aristotelian categories is purely grammatical: the first four correspond to nouns with adjectives and numerals, the last four to verbs, and the two middle ones to adverbs. A clever hypothesis that undoubtedly contains some truth, but for which there is no direct confirmation in the Aristotelian texts, where the derivation of the categories always has a distinctly theoretical setting and must therefore be traced back to metaphysics (Bonitz, Brentano, Ragnisco, Ross, along with the realist school).
The categories are grounded in and refer to ‘being’, of which they express, first in concepts and then in words, the different forms accessible in experience. Therefore, it is foreign to Aristotle’s mind even to attempt, as O. Apelt does, to see in the categories the ‘formal functions’ that the ‘is’ performs as the copula of judgment: an exegesis that is moreover constantly contradicted by the texts, which distinctly separate the logical and real meanings (v. : *Met.*, V, 7, 1017 a 8 ff; X, 10, 1051 a 35 ff., etc). One must adhere to Aristotle’s strong expression of ‘categories of being’, of ‘genera of being’, and to the declaration that ‘as many are the ways in which being is said, so many are its meanings’ (*Met.*, V, 7, 1017 a 8 ff.). The categories are ‘genera’, that is, determinations that are not further resolvable in content but in which all others of denser content within their own sphere are resolved, as can be well observed by tracing Porphyry’s tree from the bottom up. Moreover, they are called categories and genera of ‘being’, and with this it is indicated both the content and the principle of division. The categories classify real being and not the mental concepts of being, the predicables. But since they classify it in a defined, and therefore limited and univocal, form, they are no less distinct from the divisions that belong to being in the breadth of analogy: finite and infinite, act and potency, essence and existence...
Between this essentially ontological division and the purely logical division of the predicables (v.) stands the division of the categories, which thus partakes of the nature of both and can accordingly serve as a mediator between the two. And since, for Aristotle, the forms of being and their actual connection precede and ground the mind’s apprehension and connection of them, this mediation or ambivalence of the categorical classification at once ensures the rational character of his metaphysics and the realistic background of his logic. Having as their content and principle of derivation real being, that is, the composite of essence and act of being, the derivation expresses the manner in which a real nature comes to have the act of being: that nature which has so much consistency as to be able to have the act of being directly in itself, and is therefore a subsistent subject, is *substance* (v.); what instead can only be ‘in another’, as a modification of the nature of the same, is an *accident*; the accidents are then further divided according to the nature and modalities of this belonging to substance. Therefore, attempts to place at the center of the classification either movement (Bröcker), or relation (Zeller), or pure ‘essence’ as such (N. Hartmann), remain outside the Aristotelian-Thomistic realism.
Since the categories must express the economy of thought in determining reality with respect to mutable and manifold experience, the meaning and determination of the categories themselves depend on the concept of reality that a philosophy assumes at its outset. Therefore, in philosophies for which being is ‘given’ and offered to the contemplating mind (objectivism), the categories are determinations of being before they are of thought, and qualify thought only in dependence on being, whether reality is made to consist in pure subsistent forms (Platonism), or in the modalities of material concreteness (Stoic and Epicurean materialism), or in the modalities of being as such (Aristotelianism).
When, however, with Kant the ‘thing in itself’ was declared inaccessible and the judgments of truth could
More closely coinciding with those of reality, the category was reduced to a determination of thought itself: the categories express the a priori possibility of the judgments of experience that constitute the physical and mathematical sciences (synthetic a priori judgments). Kant identified twelve of these, which he divided into four groups of three each, namely according to quantity, quality, relation, and modality (Kritik der reinen Vernunft, B. 107, ed. Kehrbach 97). When viewed in their root, the categories for Kant had to express the forms according to which the spontaneity of the transcendental “I think” is realized, which, as Hegel observed, was in contradiction with the first derivation from the traditional table of judgments: the categories must be deduced with necessity from the internal and exclusive development of the subject or of thought itself (Enc., I, §§ 42-44). Thus, in the tangle of post-Kantian philosophical vegetation, the problem of the categories lost its specific meaning and receded into the background, until it was entirely eliminated in Gentilian actualism, where the “act” is everything and every thing, and always itself in every thing, in the infinite process of becoming (G. Gentile, La riforma della dialettica hegeliana, 2nd ed., Messina 1923, p. 245).
In contemporary thought, the notion of the category tends toward increasingly vague and extended uses and is applied to indicate any classification in any order: one speaks, therefore, of categories of knowing, of being, of essential, existential, logical, psychological, ethical, economic, political, religious categories, and so on; but in this way the theoretical problem that was bound up with this notion is also lost.