#jack cohen

How many times have you been in a discussion in which somebody says 'We have to decide where to draw the line'? For instance, most people seem to accept that in general terms women should be permitted abortions during the earliest stages of pregnancy but not during the very late stages. 'Where you draw the line' , though, is hotly debated - and of course some people wish to draw it and one extreme or the other. There are similar debates about exactly when a developing embryo becomes a person, with legal and moral rights. Is it at conception? When the brain first forms? At birth? Or was it always a potential person, even when it 'existed' as one egg and one sperm?

The 'draw a line' philosophy offers a substantial political advantage to people with hidden agendas. The method for getting what you want is first to draw the line somewhere that nobody would object to, and then gradually move it to where you really want it, arguing continuity all the way. For example, having agreed that killing a child is murder, the line labelled 'murder' is then slid back to the instant of conception; having agreed that people should be allowed to read whichever newspaper they like, you end up supporting the right to put the recipe for nerve gas on the Internet.

If we were less obsessed with labels and discontinuity, it would b much easier to recognize that the problem here is not where to draw the line: it is that the image of drawing a line is inappropriate. There is no sharp line, only shades of grey that merge unnoticed into one another- - despite which, one end is manifestly white and the other is equally clearly black. An embryo is not a person, but as it develops it gradually becomes one. There is no magic moment at which it switches from non-person to person - instead, it merges continuously from one into the other. Unfortunately our legal system operates in rigid black-and-white terms - legal or illegal, no shades of grey - and this causes a mismatch, reinforced by our use of words as labels. A kind of triage might be better: this end of the spectrum is legal, that end of the spectrum is illegal, and in between is a grey area which we do our best to avoid if we possibly can. if we can't avoid it, we can at least adjust the degree of criminality and the appropriate penalty according to whereabouts in the spectrum the activity seems to lie.

Even such obviously black-and-white- distinctions as alive/dead or male/female turn out, on close examination, to be more like a continuous merging than a sharp discontinuity. Pork sausages from the butcher's contain many live pig cells. With today's techniques you might even clone an adult pig from one. A person's brain can have ceased to function but their body, with medical assistance, can keep going. There are at least a dozen different combinations of sex chromosomes in humans, of which only XX represent the traditional female and XY the traditional male."

The Science of Discworld IV: Judgement Day - Terry Pratchett, Ian Stewart, and Jack Cohen

In brief: Roundworld’s being threatened—by Omnian fundamentalists! Will the wizards save it this time? And what is the nature of belief anyway? How do we know anything? Fourth in a series, part of a larger universe.

Thoughts: This is not my favourite of the Science of Discworld books, but I’m not all that surprised by that, given that Pratchett was in his final years when he helped write it. (The vim and brio are lacking for me in a lot of his later work.) The science chapters are probably about the same quality as they’ve always been, but the framing Discworld story felt even looser and more didactic than the others have.

Bear in mind it’s been years since my last Science of Discworld so I might just be misremembering things. It happens. And that I read this primarily on long-distance transit while not completely awake, so there’s that too.

Science first, because why not. I liked that the authors tackled belief systems and knowledge to cap off the series. I didn’t learn much—which might be part of what was lackluster, come to think of it—but it felt like a very fitting way to end things, to talk about what’s known, what knowing things means, how we’ve come to know fundamental things about the earth, the universe, and physics in general, and how religions fit into the picture. It’s as encompassing and inclusive as Discworld and the Science of Discworld books usually are.  They’re not saying that religion is wrong or untruthful, just that it’s different sort of truth than science provides. (There are also some discussions that continue from past books a bit, such as evolution, in that we’ve learned more since they were written.)

The Discworld segments, though… They’re a bit one-note and they felt slow. There’s not much going on besides the trial, which takes a while to get to and get through, and even though the Wizards are collecting evidence in the meantime, we don’t see that much of their work. They also don’t really feel like themselves? Sort of a watered-down version? None of that got to me really, though. What bugged me most was the addition of Marjorie Daw.

I can see the narrative point of bringing her in as an outsider POV in the chaos of the Wizards, but she didn’t seem to have much to do besides that. Ask a few questions in a quasi-Socratic dialogue and occasionally make outbursts, but that was it. Oh, and provide a little bit of atheist/librarian humour. She didn’t feel believable to me, let alone rounded the way I’m used to, and it make the whole thing feel a bit flat as a result. Like adding her was a cop-out.

So now I come down to my usual questions of whether I’d recommend this and to whom. I’m not sure. The science sections are interesting with some good food for thought but I didn’t find them enlightening or mind-blowing, but the Discworld parts are nothing to write home about. I guess if you’re a completist Discworld fan? If you’ve read the other Science of Discworlds? But this isn’t the one to start with, by any means.

Warnings: Sexism. Religious extremists, slightly mocked. Possible shaking of one’s beliefs about the world and one’s role in it, though probably not to the point of existential crisis.

*Lord Vetinari, the Patrician and supreme ruler of the city, took proper food labelling very seriously. Unfortunately, he sought the advice of the wizards of Unseen University on this one, and posed the question thusly: “Can you, taking into account multi-dimensional phase space, meta-statistical anomaly and the laws of probability, guarantee that anything with absolute certainty contains no nuts at all?” After several days, they had to conclude that the answer was “no.” Lord Vetinari refused to accept “Probably does not contain nuts” because he considered it unhelpful.