What is the meaning of “meaning”?
This apparently recondite question, posed by the philosopher Hilary Putnam in a seminal 1975 paper, actually lies at the core of the branch of linguistics known as semantics. How we answer this question will have important implications for a variety of issues that are currently hotly debated in linguistics, such as whether some concepts are innate, whether different languages create different styles of thought or experience (linguistic determinism), how languages are learned, and so on. In the second half of the 20th century, the prevalent commonsense view of meaning faced a number of serious challenges, but none was as potentially revolutionary as that raised by Putnam and other similarly minded philosophers of language.
I always begin my Philosophy of Language course by asking students what they take to be “the meaning of ‘meaning,’” and the most common initial response is, in short, that meaning is something in the head. The meaning of a sentence like “It’s six pm in Denver now” is a thought in the mind of the speaker, presumably the thought that right now the time in Denver is six pm; the meaning of a word, for instance “cauliflower,” is the speaker’s concept of that thing. This view is a very commonsensical one for us today, and also one with a long historical pedigree.
The 17th century philosopher John Locke held that a man’s words “stand as marks for the ideas in his own mind, whereby they might be made known to others, and the thoughts of men’s minds be conveyed from one to another.”
But Putnam and other philosophers, such as Saul Kripke, raised deep-seated objections to the idea theory, objections whose implications philosophers and linguists are still trying to unravel. Putnam’s challenge takes the form of a thought experiment involving a make-believe planet called “Twin Earth.” Imagine, he says, that somewhere in the universe there is a planet that is, with one exception, molecule for molecule identical with Earth. On Twin Earth there are twin trees and twin rocks. There are even doppelgangers of you and me, who speak something that sounds just like English. The only difference between the two planets is that on Twin Earth, the lakes and rivers don’t contain H2O, but a substance with a different chemical formula we can abbreviate XYZ. XYZ is, to the naked eye, indistinguishable from H2O, and Twin Earthians drink it, cook with it, and even call it by the same sound we use, “water.”
But, Putnam asks, what does the Twin Earthian word “water” mean? Clearly, it does not mean water. After all, water is H2O, not XYZ; a substance with a different chemical formula would not be called water. But—and here’s the rub—this difference of meaning would exist even if Person A on Earth and Twin Person A on Twin Earth were exactly identical in terms of what’s “in their heads.” Suppose that it’s the year 1750 (Earth time), and no one on either Earth or Twin Earth has any understanding of chemical composition. Person A and Twin Person A will then share all the same beliefs about their respective liquids: that it’s clear, odorless, thirst-quenching on a summer’s day, and so on. But even so, the meaning of Twin Person A’s term “water” cannot be water, for this term refers to XYZ, not H2O. Person A’s and Twin Person A’s “concepts” of these substances are identical, and yet the meanings of their terms are different. So meanings cannot just be concepts. As Putnam puts it, “Cut the pie any way you like, ‘meaning’ just ain’t in the head!”
Or, at any rate, not wholly in the head. Putnam’s proposal is actually that the meaning of most words includes two components: one that is not in the head, the word’s extension, or the things to which it applies (in the case of water, H2O); and one that is in the head, the word’s “stereotype.” This may seem, to put it mildly, surprising. How could H2O itself be part of the meaning of “water” in 1750, before anyone knew that water was H2O? Putnam’s idea is that “water”, and indeed most words, are actually akin to indexical words like “this,” “that,” and “now,” whose meaning depends on context. What I mean when I say “that” depends on whether I’m pointing to my cat or my car, and if I’m pointing to my cat, what I mean is the cat itself. In a similar way, the meaning of “water” “reaches out” to encompass the actual stuff in the world to which the word refers, even if the speaker doesn’t fully know the nature of that stuff.
Putnam’s view of meaning has sparked a great deal of controversy since it was proposed, but it has had a tremendous influence. What are its implications? What it means for broader questions concerning, for instance, the innateness of language and linguistic determinism, is still very much a subject of debate. However these specific issues are decided, this new perspective has suggested to many a broad reorientation of our way of thinking about the relationship between the mind and the world. The idea theory of meaning, by picturing meaning as something wholly within the speaker’s head, in a sense separates the mind from the world. On Putnam’s view, the meanings we grasp with our minds encompass things outside the mind, which suggests we should think of the mind as fundamentally open to the world, rather than closed in on itself.
For those who accept Putnam’s argument, there is much work to be done in order to understand what exactly this means about the nature of human subjectivity and its relation to the world.
John Spackman is an associate professor of philosophy. He teaches a course at Middlebury titled “Philosophy of Language.”