[91] See Metaphysic. Δ. p. 1020, b. 26, p. 1021, b. 10. Trendelenburg observes (Gesch. der Kategorienlehre, pp. 118-122, seq.) how much more the description given of πρός τι in the Categoriæ is determined by verbal or grammatical considerations, than in the Metaphysica and other treatises of Aristotle.
[92] See Ethic. Nikomach. i. p. 1096, a. 20: τὸ δὲ καθ’ αὑτὸ καὶ ἡ οὐσία πρότερον τῇ φύσει τοῦ πρός τι· παραφυάδι γὰρ τοῦτ’ ἔοικε καὶ συμβεβηκότι τοῦ ὄντος, ὥστε οὐκ ἂν εἴη κοινή τις ἐπὶ τούτων ἰδέα. (The expression παραφυάδι was copied by Andronikus; see a [note] on the preceding page.) Metaphys. N. p. 1088, a. 22-26: τὸ δὲ πρός τι πάντων ἥκιστα φύσις τις ἢ οὐσία τῶν κατηγοριῶν ἐστί, καὶ ὑστέρα τοῦ ποιοῦ καὶ ποσοῦ· καὶ πάθος τι τοῦ ποσοῦ τὸ πρός τι, ὥσπερ ἐλέχθη, ἀλλ’ οὐχ ὕλη, εἴ τι ἕτερον καὶ τῷ ὅλως κοινῷ πρός τι καὶ τοῖς μέρεσιν αὐτοῦ καὶ εἴδεσιν. Compare Bonitz in his note on p. 1070, a. 33.
The general doctrine laid down by Aristotle, Metaphys. N. p. 1087, b. 34, seq., about the universality of μέτρον as pervading all the Categories, is analogous to the passage above referred to in the Politicus of Plato, and implies the Relativity involved more or less in all predicates.
[93] Aristot. Metaph. N. p. 1088, a. 29: σημεῖον δὲ ὅτι ἥκιστα οὐσία τις καὶ ὄν τι τὸ πρός τι τὸ μόνον μὴ εἶναι γένεσιν αὐτοῦ μηδὲ φθορὰν μηδὲ κίνησιν, ὥσπερ κατὰ τὸ ποσὸν αὔξησις καὶ φθίσις, κατὰ τὸ ποιὸν ἀλλοίωσις, κατὰ τόπον φορά, κατὰ τὴν οὐσίαν ἡ ἁπλῆ γένεσις καὶ φθορά. Compare K. p. 1068, a. 9: ἀνάγκη τρεῖς εἶναι κινήσεις, ποιοῦ, ποσοῦ, τόπου. κατ’ οὐσίαν δ’ οὔ, διὰ τὸ μηθὲν εἶναι οὐσίᾳ ἐναντίον, οὐδὲ τοῦ πρός τι. Also Physica, v. p. 225, b. 11: ἐνδέχεται γὰρ θατέρου μεταβάλλοντος ἀληθεύεσθαι θάτερον μηδὲν μετάβαλλον. See about this passage Bonitz and Schwegler’s notes on Metaphys. p. 1068.
[94] Hobbes observes (First Philosophy, part ii. ch. xi. 6): “But we must not so think of Relation as if it were an accident differing from all the other accidents of the relative; but one of them, namely, that by which the comparison is made. For example, the likeness of one white to another white, or its unlikeness to black, is the same accident with its whiteness.� This may be true about the relations Like and Unlike (see Mr. John Stuart Mill, Logic, ch. iii. p. 80, 6th ed.) But, in Relations generally, the fundamentum may be logically distinguished from the Relation itself.
Aristotle makes the same remarks upon τὸ συμβεβηκὸς as upon τὸ πρός τι:— That it verges upon Non-ens; and that it has no special mode of being generated or destroyed. φαίνεται γὰρ τὸ συμβεβηκὸς ἐγγύς τι τοῦ μὴ ὄντος· τῶν μὲν γὰρ ἄλλον τρόπον ὄντων ἔστι γένεσις καὶ φθορά, τῶν δὲ κατὰ συμβεβηκὸς οὐκ ἔστιν. (Metaphys. E. p. 1026, b. 21.)
Those among the Aristotelian commentators who denied the title of Ad Aliquid to a place among the Categories or Summa Genera of predicates, might support their views from passages where Aristotle ranks the Genus as a Relatum, though he at the same time declares that the Species under it are not Relata. Thus scientia is declared by him to be a Relatum; because it must be of something—alicujus scibilis; while the something thus implied is not specified.[95] But (scientia) musica, grammatica, medica, &c., are declared not to be Relata; the indeterminate something being there determined, and bound up in one word with the predication of Relativity. Now the truth is that both are alike Relata, though both also belong to the Category of Quality; a man is called Talis from being sciens, as well as from being grammaticus. Again, he gives as illustrative examples of the Category Ad Aliquid, the adjectives double, triple. But he ranks in a different Category (that of Quantum) the adjectives bicubital, tricubital (διπῆχυς, τριπῆχυς). It is plain that the two last of these predicates are species under the two first, and that all four predicates are alike relative, under any real definition that can be given of Relativity, though all four belong also to the Category of Quantum. Yet Aristotle does not recognize any predicates as belonging to Ad Aliquid, except such as are logically and grammatically elliptical; that is, such as do not include in themselves the specification of the Correlate, but require to be supplemented by an additional word in the genitive or dative case, specifying the latter. As we have already seen, he lays it down generally, that all Relata (or Ad Aliquid) imply a Correlatum; and he prescribes that when the Correlatum is indicated, care shall be taken to designate it by a precise and specific term, not of wider import than the Relatum,[96] but specially reciprocating therewith: thus he regards ala (a wing) as Ad Aliquid, but when you specify its correlate in order to speak with propriety (οἰκείως), you must describe it as ala alati (not as ala avis), in order that the Correlatum may be strictly co-extensive and reciprocating with the Relatum. Wing, head, hand, &c., are thus Ad Aliquid, though there may be no received word in the language to express their exact Correlata; and though you may find it necessary to coin a new word expressly for the purpose.[97] In specifying the Correlatum of servant, you must say, servant of a master, not servant of a man or of a biped; both of which are in this case accompaniments or accidents of the master, being still accidents, though they may be in fact constantly conjoined. Unless you say master, the terms will not reciprocate; take away master, the servant is no longer to be found, though the man who was called servant is still there; but take away man or biped, and the servant may still continue.[98] You cannot know the Relatum determinately or accurately, unless you know the Correlatum also; without the knowledge of the latter, you can only know the former in a vague and indefinite manner.[99] Aristotle raises, also, the question whether any Essence or Substance can be described as Ad Aliquid.[100] He inclines to the negative, though not decisively pronouncing. He seems to think that Simo and Davus, when called men, are Essences or Substances; but that when called master and slave, they are not so; this, however, is surprising, when he had just before spoken of the connotation of man as accidents (συμβεβηκότα) belonging to the connotation of master. He speaks of the members of an organized body (wing, head, foot) as examples of Ad Aliquid; while in other treatises, he determines very clearly that these members presuppose, as a prius naturâ, the complete organism whereof they are parts, and that the name of each member connotes the performance of, or aptitude to perform, a certain special function: now, such aptitude cannot exist unless the whole organism be held together in co-operative agency, so that if this last condition be wanting, the names, head, eye, foot, can no longer be applied to the separate members, or at least can only be applied equivocally or metaphorically.[101] It would seem therefore that the functioning something is here the Essence, and that all its material properties are accidents (συμβεβηκότα).
[95] Categor. p. 6, b. 12, p. 11, a. 24; Topic. iv. p. 124, b. 16. Compare also Topica, iv. p. 121, a. 1, and the Scholia thereupon, p. 278, b. 12-16, Br.; in which Scholia Alexander feels the difficulty of enrolling a generic term as πρός τι, while the specific terms comprised under it are not πρός τι; and removes the difficulty by suggesting that ἐπιστήμη may be at once both ποιότης and πρός τι; and that as ποιότης (not as πρός τι) it may be the genus including μουσικὴ and γεωμετρία, which are not πρός τι, but ποιότητες.
[96] Categor. p. 6, b. 30, p. 7, b. 12.
[97] Categor. p. 7, a. 5. ἐνίοτε δὲ ὀνοματοποιεῖν ἴσως ἀναγκαῖον, ἐὰν μὴ κείμενον ᾖ ὄνομα πρὸς ὃ οἰκείως ἂν ἀποδοθείη.