Rhetorica:
The Topoi,
I. Definition
By Gabriel Blanchard
Let us begin, like ancient philosophers, with being.
I Tell You a Mystery
The first of the four principal topoi is definition, a topic we have touched on here at the Journal once or twice before now. However, we are here dealing with something more than “what words mean”; in fact, we are touching on why we use words at all. There is philosophical debate about this, which the present author does not feel equal to wading into in full. The following will, he hopes, serve as a reasonably impartial sketch of the parts of that discussion that are relevant to our purpose here.
What we call a word consists in two things joined together:
- A sign, either audible (consisting in a set of one or more vocal sounds) or visual (consisting one or more gestures1 or characters of a script).
- A signified meaning, i.e. a concept attached by some agreed convention to that sign.
All words have both components. Any vocal or visual set that lacks the second element “doesn’t mean anything,” while any concept that lacks the first is something we “don’t have a word for” (though we may be able to describe it all the same). Generally, when we use the word definition, we’re talking about the process of lining up those two elements more precisely—something we achieve by using other words as a sort of calibration technique. The reason we can learn foreign languages is that, with enough time at our disposal, we can do either of two things: figure out what the speakers of a foreign language use their signs to mean the long way around, almost like children; or, appropriate the efforts of others who have done so before us. (The latter is by far the more usual method, and typically much better, since it means collaborating with said predecessors and therefore getting to use not just our own wisdom, but theirs as well.)
We Talk In a Society
However, the very nature of definition, as explained here, shows that we are dealing with something more and other than language; for it is of the nature of language to deal with other things than itself—that is what language, as a tool, is designed to do. Specifically, language is a tool intended to transport concepts (or strings of concepts) from one mind to another. This means there are two other things to discuss here: minds, i.e. people; and concepts, or ideas.
"So: they say all men have the same substantial form, am I right?"
"Of course," I said, proud of my knowledge, "men are animals but rational, and the property of man is the capacity for laughing."
"Excellent. But Thomas is different from Bonaventure, Thomas is fat while Bonaventure is thin, and it may even be that Hugh is bad while Francis is good, and Aldemar is phlegmatic while Agilulf is bilious. Or am I mistaken?"
"No, that is the case, beyond any doubt."
Language is a tool built by society in general, which is why the phrase “by some agreed convention” needs to be there in the explanation of the second element. If a person tried to behave like Lewis Carroll’s Humpty-Dumpty, redefining words purely on a whim, they would not succeed—not so much because people would stop them, more just because people wouldn’t even grasp what they were doing. Someone leaning out of a window and shouting “Horse! Horse!” because, by horse, they privately meant “fire,” would not get their meaning across to others, because there is already a consensus among English speakers that the sound sequence h-õ-ŕ-s does not point to that concept and does point to the celebrated equid. They couldn’t even get others to realize what their actual meaning was, except by resorting to the consensus meanings of terms.
Neologisms and changes in meaning are a different case. Sometimes the latter happen organically and more or less imperceptibly (for instance, it was probably via generations of increasingly sarcastic use that adjectives like pompous and sanctimonious became negative). That aside, individuals can and do try to coin words, or to redefine existing words. Sometimes they are successful; sometimes they are not; and sometimes they are half-successful—coiners may get the sign they wanted into common use, but with some other signified concept attached to it, while redefiners may manage to ruin a word for one or more uses without getting their preferred new usage accepted. (This, incidentally, is what is really meant by the academic expression “social construct.” Social constructs are not “fake,” any more than language is fake, but they don’t just grow spontaneously, the way a mushroom would—their development involves human decision, yet at a collective level exceeding anyone’s individual powers.)
We Have an Idea, And If You Don’t Like It We Have Others
And what is it we need to explore about ideas here? Simply this: Whatever our theory of ideas may be—Postmodern or Platonic or anything in between—the ideas conveyed by the signs of language are something other than those signs. The fact that we can “not have a word for” something points to the same reality. This means in turn that the language we use can be well- or ill-suited to the thought we are trying to express. It also means that coherence lies not in whether our signs are “the right ones” (whatever that may mean from one context to another), but in the ideas themselves.
Definition, as a rhetorical topos, is an appeal to those underlying ideas—not just to how words are defined in a dictionary sense. It is an appeal to a thing’s being, arguing that such-and-such a thing must, or cannot, be true of it. In fact, it is the sort of thing we may recollect from the square of opposition, especially from its universal statements, the A and E statements, “All S are P” and “No S are P.” It is exceedingly difficult to show by experiment that something is true about all the particulars of some category; you would have to first gather each of the particulars and then show that the something was true of each one in turn. Accordingly, most people don’t bother—they either employ inductive reasoning to make a guess that’s good enough for practical purposes, or they appeal to what something is by definition: in other words, this topos.
In principle, this is therefore the most potent of the four common topoi. An argument based on what is inherently true about something is, obviously, going to be more challenging than most to circumvent … if the inherent truth in question is accepted by all parties. However, that is its weakness. Arguments over how a word or idea should be defined are at least as common as effectively-deployed uses of the topos of definition. This does not mean it is useless or should be avoided—far from it!—but serves as a caution not to mistake it for an abracadabra.
1In the case of sign language.
Gabriel Blanchard may be provisionally defined as a rational animal employed by the Classic Learning Test as its editor at large, living in Baltimore, MD.
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Published on 5th June, 2025.