Yesterday's link to the comprehensive list of chemical-free products led to some smiles, but also to some accusations of preaching to the choir, both on my part and on the part of the paper's authors. A manuscript mentioned in the blog section of Nature Chemistry is certainly going to be noticed mostly by chemists, naturally, so I think that everyone responsible knows that this is mainly for some comic relief, rather than any sort of serious attempt to educate the general public. Given the constant barrage of "chemical-free" claims, and what that does to the mood of most chemists who see them, some comedy is welcome once in a while.
But the larger point stands. The commenters here who said, several times, that chemists and the public mean completely different things by the word "chemical" have a point. But let's take a closer look at this for a minute. What this implies (and implies accurately, I'd say) is that for many nonscientists, "chemical" means "something bad or poisonous". And that puts chemists in the position of sounding like they're arguing from the "No True Scotsman" fallacy. We're trying to say that everything is a chemical, and that they range from vital to harmless to poisonous (at some dose) and everything in between. But this can sound like special pleading to someone who's not a scientist, as if we're claiming all the good stuff for our side and disavowing the nasty ones as "Not the kind of chemical we were talking about". (Of course, the lay definition of chemical does this, with the sign flipped: the nasty things are "chemicals", and the non-nasty ones are. . .well, something else. Food, natural stuff, something, but not a chemical, because chemicals are nasty).
So I think it's true that approaches that start off by arguing the definition of "chemical" are doomed. It reminds me of something you see in online political arguments once in a while - someone will say something about anti-Semitism in an Arab country, and likely as not, some other genius will step in with the utterly useless point that it's definitionally impossible, you see, for an Arab to be an anti-Semite, because technically the Arabs are also a Semitic people! Ah-hah! What that's supposed to accomplish has always been a mystery to me, but I fear that attempts to redefine that word "chemical" are in the same category, no matter how teeth-grinding I find that situation to be.
The only thing I've done in this line, when discussing this sort of thing one-on-one, is to go ahead and mention that to a chemist, everything that's made out of atoms is pretty much a "chemical", and that we don't use the word to distinguish between the ones that we like and the ones that we don't. I've used that to bring up the circular nature of some of the arguments on the opposite side: someone's against a chemical ingredient because it's toxic, and they know it's toxic because it's a chemical ingredient. If it were "natural", things would be different.
That's the point to drop in the classic line about cyanide and botulism being all-natural, too. You don't do that just to score some sort of debating point, though, satisfying though that may be - I try not to introduce that one with a flourish of the sword point. No, I think you want to come in with a slightly regretful "Well, here's the problem. . ." approach. The idea, I'd say, is to introduce the concept of there being a continuum of toxicity out there, one that doesn't distinguish between man-made compounds and natural ones.
The next step after that is the fundamental toxicological idea that the dose makes the poison, but I think it's only effective to bring that up after this earlier point has been made. Otherwise, it sounds like special pleading again: "Oh, well, yeah, that's a deadly poison, but a little bit of it probably won't hurt you. Much." My favorite example in this line is selenium. It's simultaneously a vital trace nutrient and a poison, all depending on the dose, and I think a lot of people might improve their thinking on these topics if they tried to integrate that possibility into their views of the world.
Because it's clear that a lot of people don't have room for it right now. The common view is that the world is divided into two categories of stuff: the natural, made by living things, and the unnatural, made by humans (mostly chemists, dang them). You even see this scheme applied to inorganic chemistry: you can find people out there selling makeup and nutritional supplements who charge a premium for things like calcium carbonate when it's a "natural mineral", as opposed (apparently) to that nasty sludge that comes out of the vats down at the chemical plant. (This is also one of the reasons why arguing about the chemist's definition of "organic" is even more of a losing position than arguing about the word "chemical").
There's a religious (or at least quasi-religious) aspect to all this, which makes the arguments emotional and hard to win by appeals to reason. That worldview I describe is a dualist, Manichean one: there are forces of good, and there are forces of evil, and you have to choose sides, don't you? It's sort of assumed that the "natural" world is all of a piece: living creatures are always better off with natural things. They're better; they're what living creatures are meant to consume and be surrounded by. Anything else is ersatz, a defective substitute for the real thing, and quite possibly an outright work of evil by those forces on the other side.
Note that we're heading into some very deep things in many human cultures here, which is another reason that this is never an easy or simple argument to have. That split between natural and unnatural means that there was a time, before all this industrial horror, when people lived in the natural state. They never encountered anything artificial, because there was no such thing in the world. Now, a great number of cultures have a "Golden Age" myth, that distant time when everything was so much better - more pure, somehow, before things became corrupted into their present regrettable state. The Garden of Eden is the aspect this takes in the Christian religion, but you find similar things in many other traditions. (Interestingly, this often takes the form of an ancient age when humans spoke directly with the gods, in whatever form they took, which is one of the things that led Julian Jaynes to his fascinating, although probably unprovable hypotheses in The Origin of Consciousness in the Breakdown of the Bicameral Mind).
This Prelapsarian strain of thinking permeates the all-natural chemical-free worldview. There was a time when food and human health were so much better, and industrial civilization has messed it all up. We're surrounded by man-made toxins and horrible substitutes for real food, and we've lost the true path. It's no wonder that there's all this cancer and diabetes and autism and everything: no one ever used to get those things. Note the followup to this line of thought: someone did this to us. The more hard-core believers in this worldview are actually furious at what they see as the casual, deliberate poisoning of the entire population. The forces of evil, indeed.
And there are enough small reinforcing bars of truth to make all of this hold together quite well. There's no doubt that industrial poisons have sickened vast numbers of people in the past: mercury is just the first one that's come to mind. (I'm tempted to point out that mercury and its salts, by the standards of the cosmetics and supplements industries, are most certainly some of those all-natural minerals, but let that pass for now). We've learned more about waste disposal, occupational exposure, and what can go into food, but there have been horrible incidents that live on vividly in the imagination. And civilization itself didn't necessarily go about increasing health and lifespan for quite a while, as the statistics assembled in Gregory Clark's A Farewell to Alms make clear. In fact, for centuries, living in cities was associated with shorter lifespans and higher mortality. We've turned a lot of corners, but it's been comparatively recently.
And on the topic of "comparatively recently", there's one more factor at work that I'd like to bring up. The "chemical free" view of the world has the virtue of simplicity (and indeed, sees simplicity as a virtue itself). Want to stay healthy? Simple. Don't eat things with chemicals in them. Want to know if something is the right thing to eat, drink, wear, etc.? Simple: is it natural or not? This is another thing that makes some people who argue for this view so vehement - it's not hard, it's right in front of you, and why can't you see the right way of living when it's so, so. . .simple? Arguing against that, from a scientific point of view, puts a person at several disadvantages. You necessarily have to come in with all these complications and qualifying statements, trying to show how things are actually different than they look. That sounds like more special pleading, for one thing, and it's especially ineffective against a way of thinking that often leans toward thinking that the more direct, simple, and obvious something is, the more likely it is to be correct.
That's actually the default way of human thinking, when you get down to it, which is the problem. Science, and the scientific worldview, are unnatural things, and I don't mean that just in the whole-grain no-additives sense of "natural". I mean that they do not come to most people as a normal consequence of their experience and habits of thought. A bit of it does: "Hey, every time I do X, Y seems to happen". But where that line of thinking takes you starts to feel very odd very quickly. You start finding out that the physical world is a lot more complicated than it looks, that "after" does not necessarily mean "because", and that all rules of thumb break down eventually (and usually without warning). You find that math, of all things, seems to be the language that the universe is written in (or at least a very good approximation to it), and that's not exactly an obvious concept, either. You find that many of the most important things in that physical world are invisible to our senses, and not necessarily in a reassuring way, or in a way that even makes much sense at all at first. (Magical explanations of invisible forces at least follow human intuitions). It's no wonder that scientific thinking took such a long, long time to ever catch on in human history. I still sometimes think that it's only tolerated because it brings results.
So there are plenty of reasons why it's hard to effectively argue against the all-natural chemical-free worldview. You're asking your audience to accept a number of things that don't make much sense to them, and what's worse, many of these things look like rhetorical tricks at best and active (even actively evil) attempts to mislead them at worst. And all in the service of something that many of them are predisposed to regard as suspicious even from the start. It's uphill all the way.