In Boethius’s Latin translation of Porphyry’s Isagoge, “aph’enos” and “pros hen” are rendered respectively as “ab uno” (the term “medical” used both for the doctor himself and for the doctor’s potions and instruments) and “ad unum” (the classical example of “healthy” said of the body, the medicine, and the urine). Clearly, however, the first example is a relatively weak one, since it could be reduced to a case of paronymy. In fact the concept that remains central in Aristotle is that of pros hen. Briefly put, to be named for the cause one proceeds from or for the end toward which one tends is to all intents and purposes the same thing (we could say that the relationship is based on a common cause, whether it be efficient or final). What we have, then, are two forms of equivocity, pros hen, which the scholastic tradition will dub analogy of proportion (and, in the case of Cajetanus, of attribution), and that by analogy, which the scholastic tradition will dub analogy of proportionality. For convenience sake, from now on we will use the two terms attribution, which for Aristotle was not a form of analogy, and proportionality, which for Aristotle was the only form of analogy.
Aristotle explains the attribution in the Metaphysics (K. 3, 1060b 36–1061a 7) where he takes as examples of speaking “in several ways” the adjectives medical and healthy: they are used in reference to (pros) the same thing: a medical discourse and an instrument are both called “medical” because the medical discourse proceeds from medical science and the instrument is useful to that science; in like manner, things that are signs or causes of health are termed “healthy.” Now, health is something that is only found in a body and is not present in the color of the urine or that of the medicine (we ought to speak, then, of a patently equivocal situation in which a single term is referred to things that have different definitions). Both the urine and the medicine, however, refer to health. Just as the term being is used in various senses but with reference to one central idea (pros hen), and is therefore not equivocal, the same goes for the term “healthy.” Both express a common notion (legonthai kath’en).
Attribution is a relationship involving two terms: medicine is healthy because it causes health, and we cannot say that medicine is to the sick body as health is to the healthy body. The case of analogy is different. Here four terms are required, as we are also reminded in the Poetics and the Rhetoric. The stone is shameless because it is to Sisyphus as the shameless man is to his victim (Rhetoric, III, 11, 1412a 5, in Bollingen ed., p. 2253). Now, whereas the examples of attribution are always given as instances of the stereotyped use of language (healthy medicine, healthy urine), for Aristotle the analogy is an instrument of knowledge, and he makes use of it, when it serves him, in his books on nature too. “The underlying nature can be known by analogy” (Physics I, 7, 191a, in Bollingen ed., p. 326).
At this point let us reconsider the very nature of metaphor. As proposed in Eco (1984a: sect. 3.8.3), let us suppose that metaphor and metonymy can be explained on the basis of a componential analysis in the form of an encyclopedia which in the definition of a given term includes its form (or morphological aspect), cause, matter, and end (or function).
Property 1, form
Sememe A
Property 2, cause
Property 3, matter
Property 4, end or function
The idea was already present among the Scholastics: see, for instance, how Thomas (De principiis naturae, 6) admits that sometimes the like properties are predicated with respect to the cause, and at others with respect to the end.
To formulate the metonymy drink a glass (container for content), it is not necessary to compare two terms: one identifies in the encyclopedic definition of the glass the fact that it contains wine; the substitution is therefore one of semic interdependence within the same sememe. To call the glass the shield of Dionysus on the other hand I must compare the properties of Dionysus and the god of war Ares, recognize that in both the same morphological property appears (a typical instrument or emblem), identify a property that the two instruments have in common (both being round and concave in form), and activate the exchange. In both cases the substitution first occurs on account of the semic identity among sememes, then two sememes are crossed with two semes.
Now, it appears that metaphor imposes a comparison between two entities that were previously separate, thereby increasing our knowledge, whereas metonymy presumes prior knowledge of the thing played upon. Hence the greater cognitive power of metaphor.
Attribution seems to be akin to metonymy: we call medicine “healthy” because we already know that the property of medicine is to procure health. But if this is the case, then many of the metaphors cited by Aristotle, from genre to species and vice versa, are in fact forms of metonymy or synecdoche, given the fact that genre ought to be a property of the species. Just as being an animal is a property of mankind, and makes it possible for Francesca da Rimini to address Dante with the vocative “O aminal grazioso e benigno,” similarly standing still is a property of being at anchor. We have only to look at Emanuele Tesauro’s Cannocchiale aristotelico ([1670]1968: 284). He has no qualms about calling metaphors from genre to species and vice versa “analogiae attributionis.”
On the other hand, when Aristotle calls the stone shameless, he is attributing to it a property (certainly justified by the context) that had not previously been recognized. Let us take another look at the example calling pirates commercial purveyors. First of all, a four-term analogy is set up: the pirates are to the transportation of stolen property as merchants are to that of the goods they acquire. The impression of identifying a genre X, of which pirates and purveyors are both species, is a consequence of the analogical operation. In fact it takes two independent sememes and identifies in them a common property (that of being transporters of goods). Only when we have understood the metaphor can we say that pirates and purveyors belong (unexpectedly) to the same genre, or the same whole. The property they share, surprisingly brought to the fore, becomes a common genre.
purveyors
transporters
pirates
The entire Scholastic discussion of the analogia entis (despite the great variety of its outcomes) is fundamentally based on a choice between analogy of attribution and analogy of proportionality, and the examples are similar to those given by Aristotle when it comes to finding attributions or proportions between medicine and health and meadows and smiles.
The real problem, already looming in Dionysius, arises when the divine names come into play. When we say that medicine is healthy is that the same kind of attribution as saying that God is Good? We recognize the properties of health and we are familiar with the properties of both medicine and urine (one causes health, the other reveals it). Combining together known properties, we perform the attribution. What happens, however, in the case of the divine names?
There are only two possible solutions.35