Sunday, 21 January 2018


"We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time."

Curiosity is a virtue, and we should cultivate virtues. It's exciting that we live in an era when explanations for many of the most fundamental aspects of human existence are within reach. In particular, many age-old puzzles have been tackled using evolutionary arguments; for many more, we have tantalising hints and hypotheses but not full explanations. Below I've listed some questions in the latter category. Of course, a set of behaviours often has multiple advantages, and there may be no definitive way to weigh their relative contributions to its evolution. But I think it's likely that in many cases, compelling explanations will be found eventually; until then, it's worth reviewing some of the leading hypotheses.

  • A "false alarm" mechanism to reduce tension within groups?
  • A social bonding device? (e.g. a replacement for grooming in primates?)
Why do we age and die?
  • A group bonding mechanism?
  • A mating strategy?
  • Byproducts of the abilities to synchronise movements and notice subtle sounds?
  • A way to intimidate predators and induce an altered state of consciousness?
Why are humans instinctively monogamous?
Why do we find art attractive?
  • A side effect of adaptations which make us find bountiful landscapes and healthy humans aesthetically appealing?
  • As a status signal?
Why is there an instinct towards religion?
  • A byproduct of other traits such as being able to form theories of mind and causal narratives?
  • A group bonding mechanism which helped social hierarchies scale up to larger groups?
Why do we sleep and dream?
Why do fetishes exist?
  • Accidental cross-links between neighbouring areas in the human brain?
  • Skewed learning of sexually desirable features during childhood?
  • Standard mating strategies, simply amplified?
Why do women become infertile long before death (unlike almost all other mammals)?
  • The "grandmother hypothesis" that it's more effective to care for grandchildren than having more of your own?
  • So that they can be group leaders and repositories of knowledge?
Why does homosexuality exist?
  • Kin selection, with homosexuals better able to care for relatives' children?
  • Compensatory advantages of the relevant genes (e.g. making heterosexuals with those genes more attractive)?
  • The fact that historically, homosexuals have had children at reasonably high rates?
Are (low rates of) autism and depression evolutionarily favourable adaptions?
How did altruism evolve?
  • Mainly driven by kin selection?
  • As well as socially-enforced reciprocity?
How did life begin?
  • In tidal pools on volcanic islands?
  • In hydrothermal deep-sea vents?
  • Starting from RNA?
Those are all puzzles which hopefully will have a lot more light shed on them in the coming decades. Then there are the mysteries. I think of mysteries as big questions that we don't know how we could discover the answers to, even in principle. Before the theory of evolution, almost all of the questions above were such mysteries. Today, there are only a handful:

How did we evolve to use language?
What is consciousness?
Why did the universe begin?
Why does maths work?

Lastly, just to put you in the right frame of mind to cultivate curiosity, I want you to think about just how weird Earth is. Imagine if you'd grown up on a planet where the earth never randomly shook or poured out fire, where electricity and rocks and ice didn't shoot down from the sky, where water didn't form literally supersonic-speed waves, or float when frozen, or congeal into massive clumps in mid-air. Imagine a planet where the sun didn't just disappear from the mid-day sky at regular intervals, and where entire oceans didn't rise and fall by several metres every few hours. Imagine if your planet wasn't made up of enormous slabs of rock and molten metal crashing into each other. And then - then imagine you moved here. I bet you'd want to know why all these things happen. By that I don't just mean learning the technical mechanism, but also a deep explanation of the underlying reasons that it was this phenomenon and not another one. Does lightning occur in any sufficiently dense atmosphere? Is tectonic activity necessary to create conditions suitable for life? Or is it just a coincidence that both of these occur on our particular planet?

Is asking all these questions and learning all these explanations actually useful? Probably not. But think about how amazed our ancestors would have been that we're this close to figuring out answers to questions that seemed so intractable for so long. That sense of wonder, at least, is always worthwhile.

Sunday, 7 January 2018

Why vegetarianism?

Since I became mostly vegetarian a few months ago, it's been pretty common for people to ask why. By that they usually mean something like "Out of the standard reasons for becoming vegetarian, which one motivated you?" For me, that question doesn't really make sense, since having many reasons for a decision is much better than just having one, and in fact I'm not sure that any single reason would have swayed me by itself. But since there are more reasons to be vegetarian than people think, I want to discuss them briefly here.
  1. Animal welfare
    • I don't really mind the idea of animals dying, but the months or years of suffering that most farmed animals go through is pretty horrific. If I imagine what it is like to be a conscious being undergoing those conditions, that seems a particularly compelling reason to stop eating meat.
  2. Health
    • I think the evidence is fairly clear that many forms of meat are bad for you, particularly processed meat and red meat, and particularly at the usual high levels of consumption. (Conversely, vitamin B12 is the only dietary requirement you can't get from a vegan diet, although it is found in dairy).
  3. Global warming
    • Raising farm animals produces many times more emissions per calorie than plant-based food, and also leads to the destruction of forests on a massive scale.
  4. Infectious diseases
    • The widespread overuse of antibiotics on farm animals is leading to the evolution of antibiotic-resistant diseases; it's only a matter of time before one develops which severely affects humans.
  5. Preventing food crises
    • Producing meat requires much more land, feed, water and energy than equivalent amounts of plant-based foods. Producing less meat lessens vulnerability to sharp changes in any of those inputs.
Note that different arguments apply more to different types of meat. For example, chickens and fish are the worst to eat on animal welfare grounds (since they're so small, hundreds of chickens or fish need to be bred for the same amount of meat as one cow; perhaps we should value their welfare less than cows', but not hundreds of times lower). However, cows produce the most emissions, and they're the worst for you in terms of health. Pigs are somewhere in the middle on all those metrics. If you're not going to go entirely vegetarian, I'd recommend cutting out chicken entirely, and eating only small amounts of the others. Unfortunately, it's quite difficult to convert abstract arguments into practical commitments. Here are a couple of motivational tactics and arguments that I find particularly useful.
  1. Slavery
    • The justifications I used for eating meat are very similar to those which a slave owner might have used; I want to be morally better than that. Also, the attitudes of future generations towards carnivorism will probably be very similar to our current attitudes about slaveholding.
  2. Individual effects
    • It might not feel like individually stopping has much impact. But if nobody eats meat, all meat production will shut down. If consumption decreases by 10%, then about 10% of production will shut down. If consumption decreases by one factory-farm's output, then on average one factory farm will shut down. If that takes 1000 people giving up meat, then it's probably reasonable to think you've each saved 1/1000 of the animals that would have been raised there, i.e. roughly however many animals you ate.
  3. Realism
    • None of the arguments against eating meat are knock-down proofs it's bad in all cases. If you spend a lot of effort making sure all your meat is ethically sourced (unfortunately, the free-range label isn't enough to ensure that), from farmers who don't use antibiotics, and raised in places which aren't viable for other crops; if you also avoid red meat and processed meat, and pay for carbon credits to offset environmental impact - then you're probably not doing any harm. But realistically, you're not going to do that. Fortunately it's less effort (and a better example to others) simply to become vegetarian.
  4. Incrementalism
    • I'm currently cutting down on eggs, because the suffering that battery hens go through is comparable to the suffering of those raised for food. However, you don't need to do so in one swoop. A tactic my friends and I have been using is to stop eating any visible eggs, while ignoring those in cakes, etc. Similarly, halving your meat intake is about half as good as going entirely vegetarian (although it seems easier, motivationally, to stick to a clear line).
  5. Social pressure
    • Most of my close friends are vegetarian, which helped me put pressure on myself and made it a question of when, not if, I'd become vegetarian. In fact, at one point a friend became impatient and bet me that I couldn't go vegetarian for 6 months. I wouldn't have taken the bet if I hadn't wanted to be vegetarian anyway, but since I did it was excellent motivation.

Update: Vegetarianism and veganism are great, but it's important to be aware that there may be much more impactful ways to help animals. I recently took part in a workshop where, amongst other things, we made very rough estimates of the value of donating to the Good Food Institute, a charity which funds attempts to create synthetic meat. Even using conservative numbers, it comes out shockingly high. Let's say ten million dollars donated now could speed up the end of factory farming by a month - a plausible estimate, since there's so little funding for research in this area right now, but also little reason to think we can't eventually create cheaper and better alternatives to farmed meat. There are perhaps 25 billion factory-farmed animals alive at any time, so this would save around 2 billion animal-years of suffering. So according to this estimate you could prevent 200 years of animal suffering per dollar. The point is not that this estimate is robust - it's largely speculative - but that whether you're vegetarian or not, there are probably very important things you could do to help animals very easily.

Is death bad?

This is a question close to my heart; I've been viscerally horrified by death for as long as I can remember. When I was young I refused to explain this fear to my parents, since I thought that if they really understood it, they'd suffer the same dread as I was undergoing. Now I've become quite good at ignoring it, but there are still certain strands of thought that make my stomach twist every time I contemplate them.

This longstanding emotional instinct has obviously shaped my philosophical views on death; however, it's a rather complex issue about which my opinions are still evolving. To be clear, I interpret the claim that death is bad not to mean that compulsory immortality is good, but rather that it would be good for individuals to be able to choose to postpone death, perhaps indefinitely. Nor do I desire the fate of the Cumaean Sibyl who, being granted by Apollo extended life but not extended youth, eventually shriveled away until only her voice remained. Rather, radical life extension technologies should increase the length of healthy life at least proportionately to how much they increase total lifespan (for example, by slowing or halting biological ageing). Given all of that, it is most natural to evaluate death by answering two distinct questions: whether individuals' deaths are bad for those individuals who die, and whether their deaths are bad overall. While it's difficult to draw firm conclusions, my best guess is that death is bad for most individuals, and is bad overall in most situations we will encounter, but may be ethically good when we abstract away from practical considerations. In this essay I'll explain the considerations that led me to those beliefs, and explore how to deal with this apparent paradox.

Is death bad for individuals?

The most basic argument in favour of answering yes is simply that there are certain things which make our lives good, and death prevents us from having more of those. It doesn't really matter whether you think that life gains most meaning from relationships, or achievements, or memories, or virtues, or enlightenment - the pursuit of each is cut short by untimely mortality. There's no technical or scientific reason why humans should not eventually be able to live for hundreds or thousands of years, which would allow us many times our current allotment of those joys. If we think that somebody dying very young is a tragedy compared with a 90-year life, then the most logical conclusion is that a 90-year life is also a tragedy compared with the prospect of living ten times as long.

In response to this I've heard some argue that, given more time, we'd be less motivated to work towards those valuable things, and would procrastinate our (extended) lives away. However, I think it's more difficult than that to change human psychology - if we dectuple the human lifespan, people's long-term goals would change, but much of day-to-day life would remain the same. Besides, even if people lose the willpower to pursue more difficult goals, they will still want to seize everyday happiness - and who's to say such a life is not worthwhile?

A second counterargument is the claim that our lives suffer from significant diminishing marginal returns. After all, many of us place great value on seeing new places and experiencing new things; if we ran out of those, wouldn't life become much less worthwhile? I'm skeptical that such reductions are significant enough to make this argument work, but I'll discuss it more later in this essay.

Perhaps the most sophisticated challenge to the badness of death on an individual level comes from Derek Parfit. In Reasons and Persons, he argues persuasively that we should think of personal identity as a matter of degree, not a binary relation. That is, my current self is the "same person" as my 25-year-old self to a certain extent, but only the same as my 40-year-old self to a lesser extent, and as my 80-year-old self to an even lesser extent. If I change greatly over my life then someone else who's currently similar to me might even be more "me" than my 80-year-old self is. In that case, my current attitude towards my death many decades from now should be fairly similar to my attitude towards the deaths of people similar to me - and yet while the thought of someone else dying is sad, it's not personally terrifying.

Notice, though, that this argument doesn't help old people very much; and it helps young people only by taking away any prospect of longevity. Essentially, it claims that you shouldn't be worried about dying in a few decades' time because by that time "you" will mostly have ceased to exist anyway. But even if we accept this conclusion, it's not clear why that should make us less worried about death, instead of more worried about ageing. And of course it may be psychologically impossible, or at the very least cause internal conflict, to truly treat your future self as a different person.

Is death bad overall?

When we start to consider more than just individual lives, however, a number of other concerns emerge. Roughly speaking, these fall into two categories: those which are based on population size and welfare; and those which appeal to more standard liberal intuitions about the qualities of just and equitable societies. Starting with the former: it seems very likely that radically increased longevity would also radically decrease the birth rate, for a number of reasons. Firstly, somebody living five times as long probably won't want five times as many children. Secondly, if they did, the population would rise dramatically, to the point where Earth would likely have difficulty sustaining them, quality of life would significantly decrease, and population control would be implemented. Philosophers who accept the Repugnant Conclusion may well hold that the latter scenario would be good. However, it’s difficult to predict how the Earth’s carrying capacity will change over time, and whether its population will stay beneath it without enduring severe hardships such as widespread famine. In particular, if we solve global warming before we get longevity technology, then an increased population could be good; but if not, it would likely be a disaster. For simplicity, let's consider the case where every couple has exactly 2 children no matter how long they live. Then we face the following conundrum: is it better to have x people living for y years each, or increase longevity and have x/n people living for y*n years each? The population at each time is the same either way, it's merely the distribution of those lives which changes.

This puts the argument from diminishing marginal returns in a new light. For death to be good on a population level, it's not necessary that our lives end up with negative value as our lifespans increase. Instead, it simply needs to be the case that our longer lives end up worse, on average, than those of the children who would have replaced us. Is that likely? Anders Sandberg argues that with longer lives we would "waste" less time, proportionately, in early childhood and in ill health during old age. However, less of our lives would be spent on new and exciting experiences. The importance of the latter effect depends on whether what we value is more like life satisfaction or more like hedonic experiences. If the former, then repeating experiences probably won't provide much more satisfaction in the overall picture - winning Olympic gold twice is probably not twice as satisfying as winning once. Perhaps we could even get a rough idea of the drop-off in marginal value by asking people questions like whether they prefer another 25 years of healthy life for certain over a 50% chance of another 60 years of healthy life and a 50% chance of imminent death. (However, it's unclear how much of a bias towards the former would be introduced by risk aversion.) On the other hand, if hedonic experiences are what we care about, then it's very salient that people actually report being happiest around their 70s, and so it seems plausible that we could be equivalently happy for much longer than the normal lifespan.

It's also plausible that many people would be significantly happier than that, because a great deal of sorrow usually accompanies both the deaths of loved ones and the contemplation of one's upcoming death. However, this grief seems to usually be manageable when such deaths come at a "natural age"; also, it seems that most people don't actually worry very much about their mortality. Perhaps that is due to an irrational acceptance of death; but it feels circular to argue that death is bad partly because, if people were rational about how bad death is, they would be very sad.

I will consider three more effects, each linked to standard liberal concerns. The first is that longevity allows for greater concentration of power and wealth, which leads to the harmful sort of inequality. If dictators lived for centuries, there'd be far fewer opportunities to transition out of repressive regimes. Even in democracies, certain dynasties already have very disproportionate influence in politics - see the Gandhis in India, the Kennedys and Bushes in America, chaebols in Korea - and business. However, this has been balanced by regression to the mean - the descendants of a particularly successful individual are usually not as talented or driven as they were, and so end up squandering their opportunities (see, for instance, the dissipated fortunes of America's robber barons). But if the best businesspeople had not only vast capital accumulated over time, but also a wealth of experience and an "old-boys network" developed over centuries, they might well be impossible to displace. Some also argue that elites will get much better access to longevity technology, adding a new dimension of inequality. Overall it seems much more likely to me that longevity technology becomes like laptops or smartphones or pharmaceuticals, which all quickly became widely affordable. However, there's no denying that the people at the very bottom would lose out - in particular, there will likely be significant international inequality in access to longevity technology.

There are, however, advantages to society from similar mechanisms. For example, the best scientists will be around longer, able to learn more and contribute more; the same will be true for great leaders. Meanwhile the average citizen will be significantly more mature and well-informed than they are now. But , it doesn't seem like these advantages scale up to the same degree as the disadvantages: scientists generally do their best work while young (to the extent that studies have argued that science advances "one funeral at a time"); we are rightly suspicious of even good leaders who hold on to power too long; and there's no clear trend of older people making better political choices (in fact, by the standards of the young, it's the opposite).

That leads us to the second effect, which is the potential for slowed cultural evolution, or else a vast cultural gap. We tend to think of the cultural and moral developments that have taken place over the last few millennia to be largely a good thing. Obviously we're massively biased in thinking this, since all of this development has led to the societies that produced us. However, there are still plenty of changes in mindset which seem likely to occur eventually, if trends continue, and which we should look forward to. These include increased concern for the moral status of animals (and the end of factory farming), decreased racism, more freedom for individuals to be nonconformist, opener borders and a greater focus on reducing global poverty. With longer lifespans, it'll take more time for these to come about. Of course, there are ongoing negative changes (such as increasing atomisation and political polarisation) which may also be slowed, but on balance slowing change seems harmful. There's also the possibility that younger segments of the population will end up with a significantly different cultural outlook to their elders, which will foster unrest and perhaps even violent conflict (imagine, for instance, the elite eating meat when much of the population sees this as equivalent to slavery).

A third effect which seems likely is a greater focus on long-term issues such as climate change and existential risk. When people are more likely to experience severe effects from these issues first-hand, it seems obvious that they will do more to prevent them. However, I'm not convinced that people currently ignore these issues because of lack of motivation, since many claim that they value the quality of life of their children or grandchildren very highly. I suspect that even if human lifespans drastically increase, people are just so bad at emotionally connecting with the long-term future that their behaviour won't change much.

So what?

The difficulty in weighing the comparative magnitude of these effects is that we cannot reason about a major change to society while assuming that all else remains the same. It's conceivable that in the next few decades, the specific mechanisms behind ageing will be identified and reduced in roughly the same way that we've previously targeted diseases. However, it's far more likely that defeating ageing requires a technological breakthrough which will vastly reshape society independent of its effect on ageing. The main candidates are genetic modification, nanotechnology, brain emulation technology and superintelligent AI. The arguments above are most relevant if it's the first of those, but even in that case it's difficult to guess how much they will still apply if people can also engineer themselves to be smarter and happier, or engineer the biosphere so that the Earth can support dozens of times the current population.
Yet even hundreds of billions of people pale in comparison to the potential trillions upon trillions who could arise if humanity continues to flourish into the far future. And the same technologies which might allow us to cure ageing would also allow us to destroy ourselves with bioengineered pandemics and unsafe AI, especially if we develop them before measures are in place to mitigate those risks. So even if ending death is an urgent moral priority, it is better to focus on ensuring the safety of these technologies first. On the purely philosophical side of things, I find myself stuck. I cannot displace the intuition that death is the worst thing that will ever happen to me - on an individual level, a moral atrocity - and that I should delay it as long as possible. However, from the standpoint of population ethics it's quite plausibly better that more people live shorter lives than that fewer people live longer lives. This gives us the strange result that we could prefer a world in which many moral atrocities occur to a world in which very few do, even if the total number of years lived is the same, and the average welfare of those years is very similar. More technically, this is a conflict between a population ethics intuition which is person-affecting (roughly, the view that acts should only be evaluated by their effects on people who already exist) and one which is not. I think there are very good reasons not to subscribe to person-affecting moral theories - since, for example, they can relatively easily endorse human extinction. The problem is that our normal lives are so much based on person-affecting beliefs that being consistent is very difficult - for example, it feels like the moral value of having a child is almost negligible, even though it's roughly consequentially equivalent to saving a life.

To conclude: I don't really know. I'm going to sign up for cryonics, at least. While I still hate the thought of dying, I don't think that I'll spend much time on longevity-specific topics in the coming years - it's more important to explore ways to safely harness new technology in general. But in the best possible future - if you'll indulge me for a minute - there won't be a trade-off between looking out for our descendants and living longer ourselves. Humanity will multiply and stretch out to encompass the galaxy and beyond. And then? Well, as Donne said: "death shall be no more; Death, thou shalt die."