The book is about the importance for human life of the transmission of cultural practices, and how difficult it would have been for anyone trying to interrogate those cultural practices using (what we might describe as) pure reason.
The best example concerns manioc, a tuber native to the Americas that contains cyanide. "In the Americas, where manioc was first domesticated, societies who have relied on bitter varieties for thousands of years show no evidence of chronic cyanide poisoning. In the Colombian Amazon, for example, indigenous Tukanoans use a multistep, multiday processing technique that involves scraping, grating, and finally washing the roots in order to separate the fiber, starch, and liquid." If you don’t carry out these arduous and time-consuming steps then you die. You might think, if you were being critical about it, that these steps are really designed to make the tuber palatable. But if that is all you want to do then you can skip some of the steps and you will end up with a perfectly decent-tasting manioc product and have more time to spend on other things. But then - a long time later and in a way that you would find hard to link to the fact that you skimped on manioc processing - you would die. So your best bet is to follow all the steps of manioc preparation, even though you cannot understand why they are necessary and even though you could not understand them if you tried. Free-thinking rationalism is not your friend; blind obedience to tradition is.
You can see how this kind of story, a beefed-up Chesterton’s Fence, potentially explains lots of taboos and other cultural practices. You might think that it explains them away: once you see that, say, the dietary restrictions of Leviticus have health benefits (do they?) then you might say that you don’t need the hypothesis that God ordered them. (Not that that is a strictly logical conclusion: isn’t it more likely that a beneficent God would order you to follow rules that are beneficial to your health? I don’t think it is a disproof of the existence of my parents that I have discovered reasons for washing my hands independent of the fact that they told me to.)
But I want to go beyond this. Let’s go back to the manioc. One way of reading the story is that, by some means (trial and error, cultural evolution/memes, beneficent intervention of a deity), humans landed upon cultural practices that have practical benefits that they could not justify to themselves, but which "We", with the benefit our scientific knowledge of (e.g.) cyanide, can now understand. So now "We" can look critically at the cultural practices we have inherited - and of course "We" do so with a respectful and admiring eye, knowing that they are the result of centuries of cultural evolution, not just dismissing them as superstitious nonsense (as we would have done before we heard the manioc story) - and decide which to keep and which to throw away. So, for example, let’s say that we hear that people haven’t built in such and such an area despite humans having lived nearby for centuries. The locals say that the area is haunted or that it’s bad luck to live there. We don't just laugh. We have a look and maybe find out that it’s in a flood plain or has groundwater with some carcinogenic properties.
That’s all well and good. But we should take more from the manioc story than that. The moral I want to press on you is that even if "We" think we have understood the objective benefit of the taboo, we might be wrong. We might remove the bitterness of the manioc, so to speak, and then die - but without being able to understand the link between our deaths and our breaking of the taboo.
What I mean is this: even now our scientific knowledge is not sufficient to give us confidence that we understand the objective justifications for all our cultural practices. I’m not being dismissive of the hard sciences here: I’m sure "We" understand quite enough about which food taboos are worth keeping and which are not; there’s no replication crisis in chemistry. But our understanding of psychology and social science has not reached the same levels. Sure, we can throw out the rules of Leviticus on pork and mixed fibres if all we care about is our bodily health. But what about when it comes to our psychological and social health?
Let’s take just one example of a disturbing psychological/social development in a rich Western country, namely the alarming rise in self-harm in England: "Among 16 to 24-year-old women in 2014, 19.7% reported having self-harmed at some point in their life, compared with 11.7% in 2007 and 6.5% in 2000", says the BBC. (There are plenty of other such sad developments to choose from, e.g., "Life expectancy in Canada has stopped increasing for the first time in more than four decades, due largely to soaring overdose deaths in the Western provinces", but let’s just stick to one.) What has caused this?
The BBC’s article on self-harm says: "The triggers can be complex, but experts suggest academic pressures, and problems such as bullying or body image, are increasingly significant factors." Maybe. Or maybe those things are just the bitter taste of some underlying cyanide poisoning. Who is doing the bullying? Why are they doing it? Where does this body image problem come from?
Some might see no difficulty in saying that, obviously, growing up in the age of social media and Tinder is tougher on women than growing up in the age of Blockbuster video and landlines and so more self-harm is inevitable. But is that right? You don’t know and no one does. There is no proper, replicable, reliable science here. Think of the manioc again: you can deal with the readily observable bitterness without eradicating the long-term invisible threat of cyanide poisoning. Are mental illnesses not capable of being brought on as subtly as physical ones?
If 16-24 year-old women are in a bad way, and it seems that they are, then I’d blame the parents: maybe the cyanide here is something to do with parenting practices having changed in the last couple of generations. As a cultural conservative I might be interested in looking at, say, absent fathers or lack of church attendance. But there are left-wing alternatives too: changing work and income patterns arising from 1980s and 1990s privatisations, for example, or declines in trade union membership. Or it could be something completely different: increased male consumption of video games or pornography (which has not led to increased violence or sexual violence in societies proportionate to the increase in consumption - but might it have caused something else entirely?) or the long term effects of compulsory education and the end of child labour? I’m joking, but only a little: most of human history has seen 16-24 year old women making valuable contributions to the income or lives of their families, not just sitting in classrooms writing essays that no-one wants to write and no-one wants to read, and even "the experts" mentioned in the BBC article refer to academic pressures rather than the pressures of work or family life.
All we know for certain is that the last couple of generations have seen massive changes to a whole range of social practices: relations between the generations (teenage rebellion was invented and has now been un-invented again as parents and children get on better now - back to the olden days on this, I suspect), marriage and sexual relations, child-rearing, work-life patterns, gender roles, religious observance, public nudity, lengthy retirements, old people in old people’s homes, tattoos, not wearing hats, doing make-up on the train, using rude words - the list goes on. We are cooking the manioc of our minds in completely different ways. And what do we know about those minds? What was it we used to do that rinsed out the cyanide of self-harm? What can the scientists tell us?
This is the state of the art in the science of psychiatry (read the link - it’s fun). The psychological sciences have made a lot of progress from a standing start not long ago, but they are not yet at the stage where they can even tell us what makes an attractive woman attractive to a heterosexual man: it’s not the waist to hips ratio; is it nubility? Or do we have no idea (other than not looking like a man)?
I don’t think increasing self-harm is related to the fact that men don’t wear hats any more or are prepared to spend large sums of money on cups of coffee. But these things can be pretty complicated. If you read the link to Alexander’s review at the top of this piece then you will see why divination using birds or bones is in fact a good idea for hunting caribou or planting crops. If you haven’t yet read the link, try to work out why that might be before you do so. This stuff is tricky, even when we do understand what is going on.
Note also that being half-right about what is going on is not necessarily any better than blindly following tradition. Imagine visiting the Tukanoans with a feminist sensibility, seeing their women working hard on the manioc (Tukanoan women spend about a quarter of the day detoxifying manioc) and concluding that the social purpose of manioc preparation from an objective standpoint is the subjection of women in a patriarchal society. You might be half-right about that: it might be that women are forced to do the work in order to keep them down while the men swan about writing blog posts. But you’d be wrong if you thought no one needed to do the work. Liberate the women by stopping intensive manioc preparation and you would condemn everyone to cyanide poisoning. Let’s take the analogy back to England: maybe a woman’s place isn’t in the home and a man doesn’t need to wear a hat; but perhaps, for psychological health, someone needs to be in the home or someone needs to wear a hat (or someone needs to [your theory here]).
The manioc story has a sad epilogue: "At the beginning of the seventeenth century, the Portuguese transported manioc from South America to West Africa for the first time. They did not, however, transport the age-old indigenous processing protocols or the underlying commitment to using those techniques. ... Even after hundreds of years, chronic cyanide poisoning remains a serious health problem in Africa." Will an African one day write a book that explains the causes of self-harm and then sadly concludes: "Even after hundreds of years, self-harm among young women remains a serious health problem in England"?
