Handbook of the History of Logic: - Fordham University Faculty

Logic and Theories of Meaning . . . 367
the equivocation: (1) resemblance (similitudo), (2) proportion (proportio, Greek:
analogia), (3) “of one origin” (ab uno) and (4) “in relation to one ” (ad
unum). Boethius’ example of a term that falls within the second group is ‘principle’
(principium), which designates unity in relation to number or point in relation
to line. 103 This example shows that analogia in the Aristotelian sense refers to a
similarity of two proportions involving at least four items. In the thirteenth century,
however, what came to be called analogia (Latin: proportio) covered what
Aristotle called pros hen equivocation, which corresponds to the last two items in
Boethius’ division, with the result that the term ‘analogia’ became ambiguous. 104
In the first sense the analogy consists in a comparison of two proportions (as in:
A is to B as C is to D). Late 13 th -century logicians do not seem to be interested in
this kind of analogy, also called ‘analogy of proportionality’. 105 The focus is solely
on the second kind of analogy, or ‘analogy of proportion’, that occurs when one
term signifies two or more objects in a prior and a posterior way (secundum prius
et posterius) and according to attribution (secundum attributionem), because of a
relationship between the primary and secondary significate. 106
Another framework for discussion was Aristotle’s De sophisticis elenchis, especially
the passage where he distinguishes between three modes of equivocation and
amphiboly: “(1) When either the expression or the name has strictly more than
one meaning (...); (2) when by custom we use them so; (3) when words that have
a simple sense taken alone have more than one meaning in combination.” 107 In
one of the logical handbooks that were used in the thirteenth century, Peter of
Spain’s Tractatus, 108 Aristotle’s division is interpreted as follows:
1. the first mode of equivocation occurs when one word signifies several things,
for example ‘dog’ signifying a barking animal, a marine animal and a constellation
of stars,
2. the second mode occurs when one word signifies one thing primarily and
another secondarily (secundum prius et posterius), for example ‘healthy’ can
be said of a person and in a derivative way of urine,
3. the third mode occurs when a word has several consignifications. In this case,
the noun or expression signifies several things in a context, isolated however,
only one. The standard example of the third mode of equivocation is that of
laborans, as it appears in the syllogism: “Whoever was being cured is healthy,
the sufferer (laborans) was being cured; therefore the sufferer is healthy.” A
standard example of the third mode of amphiboly is: “The bishops (episcopi)
are priests, these asses are the bishop’s (episcopi); therefore these asses are
priests.” In Peter’s view the definition of equivocation applies more in the
103For references, see Ashworth [1996, pp. 234–6].
104Ashworth [1991, p. 41] and [1996, p. 236].
105Thomas Aquinas, De veritate, qu. 2, a. 11.
106Ashworth [1996, p. 237].
107166a15-20. 108Peter of Spain, Tractatus VII, De fallaciis, [ed. De Rijk, pp. 99–104].