For Cameron Neylon, because he kept asking me for this…

The Sapir-Whorf hypothesis1 states that language affects thought — how we speak influences how we think. Or, at least, that’s one form of the hypothesis, the weak form. The strong form of Sapir-Whorf says that language determines thought, that how we speak forms a hard boundary on how and what we think. The weak form of Sapir-Whorf says that we drive an ATV across the terrain of thought; language can smooth the path in some areas and create rocks and roadblocks in others, but it doesn’t fundamentally limit where we can go. The strong form, in contrast, says we drive a steam train of thought, and language lays down the rails. There’s an intricate maze of forks and switchbacks spanning the continent, but at the end of the day we can only go where the rails will take us — we can’t lay down new track, no matter how we might try.

Most linguists today accept that some form of the weak Sapir-Whorf hypothesis must be true: the language(s) we speak definitely affect how we think and act. But most linguists also accept that the strong Sapir-Whorf hypothesis can’t be true, just as a matter of empirical fact. New words are developed, new concepts formed, new trails blazed on the terrain of thought. Some tasks may be easier or harder depending on whether your language is particularly suited for them — though even this is in dispute. But it’s simply not the case that we can’t think about things if we don’t have the words for them, nor that language actually determines our thought. In short, while the weak form of Sapir-Whorf is probably correct, the strong form is wrong. And this makes some sense: it certainly seems like language affects our thoughts, but it doesn’t seem like language wholly determines our thoughts.

But the Sapir-Whorf hypothesis isn’t the only theory with strong and weak forms — in fact, there’s a whole pattern of theories like this, and associated rhetorical dangers that go along with them. The pattern looks like this:

1. Start with a general theoretical statement about the world, where…
2. …there are two forms, a weak form and a strong form, and…
3. …the weak form is obviously true — how could it not be? — and…
4. …the strong form is obviously false, or at least much more controversial. Then, the rhetorical danger rears its head, and…
5. …arguments for the (true) weak form are appropriated, unmodified or nearly so, as arguments for the strong form by the proponents of the latter. (You also sometimes see this in reverse: people who are eager to deny the strong form rejecting valid arguments for the weak form.)

I don’t know why (5) happens, but I suspect (with little to no proof) that this confusion stems from rejection of a naive view of the world. Say you start with a cartoonishly simple picture of some phenomenon — for example, say you believe that thought isn’t affected by language in any way at all. Then you hear (good!) arguments for the weak form of the Sapir-Whorf hypothesis, which shows this cartoon picture is too simple to capture reality. With your anchor line to your old idea cut, you veer to the strong form of Sapir-Whorf. Then, later, when arguing for your new view, you use the same arguments that convinced you your old naive idea was false — namely, arguments for the weak form. (This also suggests that when (5) happens in reverse, this is founded in the same basic confusion: people defend themselves from the strong form by attacking the weak form because they would feel unmoored from their (naive) views if the weak form were true.) But why this happens is all speculation on my part. All I know for sure is that it does happen.

Cultural relativism about scientific truth is another good example. The two forms look something like this:

Weak form: Human factors like culture, history, and economics influence the practice of science, and thereby the content of our scientific theories.

Strong form: Human factors like culture, history, and economics wholly determine the content of our scientific theories.

It’s hard to see how the weak form could be wrong. Science is a human activity, and like any human activity, it’s affected by culture, economics, history, and other human factors. But the strong form claims that science is totally disconnected from anything like a “real world,” is simply manufactured by a variety of cultural and social forces, and has no special claim to truth. This is just not true. In her excellent book Brain Storm — itself about how the weak form of this thesis has played out in the spurious science of innate gender differences in the development of the human brain — Rebecca Jordan-Young forcefully rejects the strong form of relativism about science, and addresses both directions of the rhetorical confusion that arises from confounding the weak form with the strong:

The fact that science is not, and can never be, a simple mirror of the world also does not imply that science is simply “made up” and is not constrained by material phenomena that actually exist—the material world “pushes back” and exerts its own effects in science, even if we accept the postmodern premise that we humans have no hope of a direct access to that world that is unmediated by our own practices and culturally determined cognitive and linguistic structures. There is no need to dogmatically insist (against all evidence) that science really is objective in order to believe in science as a good and worthwhile endeavor, and even to believe in science as a particularly useful and trustworthy way of learning about the world.2

Successful scientific theories, in general, must bear some resemblance to the world at large. Indeed, the success of scientific theories in predicting phenomena in the world would be nothing short of a miracle if there were absolutely no resemblance between the content of those theories and the content of the world.3 That’s not to say that our theories are perfect representations of the world, nor that they are totally unaffected by cultural and political factors: far from it. I’m writing a book right now that’s (partly) about the cultural and historical factors influencing the debate on the foundations of quantum physics. But the content of our scientific theories is certainly not solely determined by human factors. Science is our best attempt to learn about the nature of the world. It’s not perfect. That’s OK.

There are many people, working largely in Continental philosophy and critical theory of various stripes, who advocate the strong form of relativism about science.4 Yet most of their arguments which are ostensibly in favor of this strong form are actually arguments for the weak form: that culture plays some role in determining the content of our best scientific theories.5 And that’s simply not the same thing.

Another, much more popular example of a strong and weak form problem is the set of claims around the “power of positive thinking.” The weak form suggests that being more confident and positive can make you happier, healthier, and more successful. This is usually true, and it’s hard to see how it couldn’t be usually true — though there are many specific counterexamples. For example, positive thinking can’t keep your house from being destroyed by a hurricane. Yet the strong form of positive-thinking claims — known as “the law of attraction,” and popularized by The Secret — suggests exactly that. This states that positive thinking, and positive thinking alone, can literally change the world around you for the better, preventing and reversing all bad luck and hardship.6 Not only is this manifestly untrue, but the logical implications are morally repugnant: if bad things do happen to you, it must be a result of not thinking positively enough. For example, if you have cancer, and it’s resistant to treatment, that must be your fault. While this kind of neo-Calvinist victim-blaming is bad enough, it becomes truly monstrous — and the flaw in the reasoning particularly apparent — when extended from unfortunate individual circumstances to systematically disadvantaged groups. The ultimate responsibility for slavery, colonialism, genocide, and institutionalized bigotry quite obviously does not lie with the victims’ purported inability to wish hard enough for a better world.

In short, easily-confused strong and weak forms of a theory abound. I’m not claiming that this is anything like an original idea. All I’m saying is that some theories come in strong and weak forms, that sometimes the weak forms are obviously true and the strong obviously false, and that in those cases, it’s easy to take rhetorical advantage (deliberately or not) of this confusion. You could argue that the weak form directly implies the strong form in some cases, and maybe it does. But that’s not generally true, and you have to do a lot of work to make that argument — work that often isn’t done.

Again, I strongly suspect other people have come up with this idea. When I’ve talked with people about this, they’ve generally picked it up very quickly and come up with examples I didn’t think of. This seems to be floating around. If someone has a good citation for it, I’d be immensely grateful.

Image credit: Zink Dawg at English Wikipedia, CC-BY 3.0. I was strongly tempted to use this image instead.

1. This is apparently a historical misnomer, but we’ll ignore that for now. [↩]
2. Rebecca M. Jordan-Young, in Brain Storm: The Flaws in the Science of Sex Differences, Harvard University Press, 2011, pp. 299-300. Emphasis in the original. [↩]
3. See J.J.C. Smart, Philosophy and Scientific Realism, and Hilary Putnam, Mathematics, Matter, and Method. [↩]
4. Bruno Latour is the first name that comes to mind. [↩]
5. See, for example, Kuhn, who even seems to have confused himself about whether he was advocating the strong or the weak version. [↩]
6. The “arguments” in favor of this kind of nonsense take advantage of more than just the confusion between the strong and weak forms of the thesis about positive thinking. They also rely on profound misunderstandings about quantum physics and other perversions of science. But let’s put that aside for now. [↩]