Dec 7 JDN 2461017

As is commonly understood, there are two main branches of normative ethics:

• Deontology, on which morality consists in following rules and fulfilling obligations, and
• Consequentialism, on which morality consists in maximizing good consequences.

The conflict between them has raged for centuries, with Kantians leading the deontologists and utilitarians leading the consequentialists. Both theories seem to have a lot of good points, but neither can decisively defeat the other.

I think this is because they are both basically correct.

In their strongest forms, deontology and consequentialism are mutually contradictory; but it turns out that you can soften each of them a little bit, and the results become compatible.

To make deontology a little more consequentialist, let’s ask a simple question:

What makes a rule worth following?

I contend that the best answer we have is “because following that rule would make the world better off than not following that rule”. (Even Kantians pretty much have to admit this: What maxim could you will to be an absolute law? Only a law that would yield good outcomes.)

That is, the ultimate justification of a sound deontology would be fundamentally consequentialist.

But lest the consequentialists get too smug, we can also ask them another question, which is a bit subtler:

How do you know which actions will ultimately have good consequences?

Sure, if we were omniscient beings who could perfectly predict the consequences of our actions across the entire galaxy on into the indefinite future, we could be proper act utilitarians who literally choose every single action according to a calculation of the expected utility.

But in practice, we have radical uncertainty about the long-term consequences of our actions, and can generally only predict the immediate consequences.

That leads to the next question:

Would you really want to live in a world where people optimized immediate consequences?

I contend that you would not, that such a world actually sounds like a dystopian nightmare.

Immediate consequences say that if a healthy person walks into a hospital and happens to have compatible organs for five people who need donations, we should kill that person, harvest their organs, and give them to the donors. (This is the organ transplant variant of the Trolley Problem.)

Basically everyone recognizes that this is wrong. But why is it wrong? That’s thornier. One pretty convincing case is that a systematic policy of this kind would undermine trust in hospitals and destroy the effectiveness of healthcare in general, resulting in disastrous consequences far outweighing the benefit of saving those five people. But those aren’t immediate consequences, and indeed, it’s quite difficult to predict exactly how many crazy actions like this it would take to undermine people’s trust in hospitals, just how much it would undermine that trust, or exactly what the consequences of that lost trust would be.

So it seems like it’s actually better to have a rule about this.

This makes us into rule utilitarians, who instead of trying to optimize literally every single action—which requires information we do not have and never will—we instead develop a system of rules that we can follow, heuristics that will allow us to get better outcomes generally even if they can’t be guaranteed to produce the best possible outcome in any particular case.

That is, the output of a sophisticated consequentialism is fundamentally deontological.

We have come at the question of normative ethics from two very different directions, but the results turned out basically the same:

We should follow the rules that would have the best consequences.

The output of our moral theory is rules, like deontology; but its fundamental justification is based on outcomes, like consequentialism.

In my experience, when I present this account to staunch deontologists, they are pretty much convinced by it. They’re prepared to give up the fundamental justification to consequences if it allows them to have their rules.

The resistance I get is mainly from staunch consequentialists, who insist that it’s not so difficult to optimize individual actions, and so we should just do that instead of making all these rules.

So it is to those consequentialists, particularly those who say “rule utilitarianism collapses into act utilitarianism”, to whom the rest of the post is addressed.

First, let me say that I agree.

In the ideal case of omniscient, perfectly-benevolent, perfectly-rational agents, rule utilitarianism mathematically collapses into act utilitarianism. That is a correct theorem.

However, we do not live in the ideal case of omniscient, perfectly-benevolent, perfectly-rational agents. We are not even close to that ideal case; we will never be close to that ideal case. Indeed, I think part of the problem here is that you fail to fully grasp the depth and width of the chasm between here and there. Even a galactic civilization of a quintillion superhuman AIs would still not be close to that ideal case.

Quite frankly, humans aren’t even particularly good at forecasting what will make themselves happy.

There are massive errors and systematic biases in human affective forecasting.

One of the post important biases is impact bias: People systematically overestimate the impact of individual events on their long-term happiness. Some of this seems to be just due to focus: Paying attention to a particular event exaggerates its importance in your mind, and makes it harder for you to recall other events that might push your emotions in a different direction. Another component is called immune neglect: people fail to account for their own capacity to habituate to both pleasant and unpleasant experiences. (This effect is often overstated: It’s a common misconception that lottery winners are no happier than they were before. No, they absolutely are happier, on average; they’re just not as much happier as they predicted themselves to be.)

People also use inconsistent time discounting: $10 today is judged as better than $11 tomorrow, but $10 in 364 days is not regarded as better than $11 in 365 days—so if I made a decision a year ago, I’d want to change it now. (The correct answer, by the way, is to take the $11; a discount rate of 10% per day is a staggering 120,000,000,000,000,000% APR—seriously; check it yourself—so you’d better not be discounting at that rate, unless you’re literally going to die before tomorrow.)

Now, compound that with the fact that different human beings come at the world from radically different perspectives and with radically different preferences.

How good do you think we are at predicting what will make other people happy?

Damn right: We’re abysmal.

Basically everyone assumes that what they want and what they would feel is also what other people will want and feel—which, honestly, explains a lot about politics. As a result, my prediction of your feelings is more strongly correlated with my prediction of my feelings than it is with your actual feelings.

The impact bias is especially strong when forecasting other people’s feelings in response to our own actions: We tend to assume that other people care more about what we do than they actually care—and this seems to be a major source of social anxiety.

People also tend to overestimate the suffering of others, and are generally willing to endure more pain than they are willing to inflict upon others. (This one seems like it might be a good thing!)

Even when we know people well, we can still be totally blindsided by their emotional reactions. We’re just really awful at this.

Does this just mean that morality is hopeless? We have no idea what we’re doing?

Fortunately, no. Because while no individual can correctly predict or control the outcomes of particular actions, the collective action of well-designed institutions can in fact significantly improve the outcomes of policy.

This is why we have things like the following:

• Laws
• Courts
• Regulations
• Legislatures
• Constitutions
• Newspapers
• Universities

These institutions—which form the backbone of liberal democracy—aren’t simply arbitrary. They are the result of hard-fought centuries, a frothing, volatile, battle-tested mix of intentional design and historical evolution.

Are these institutions optimal? Good heavens, no!

But we have no idea what optimal institutions look like, and probably never will. (Those galaxy-spanning AIs will surely have a better system than this; but even theirs probably won’t be optimal.) Instead, what we are stuck with are the best institutions we’ve come up with so far.

Moreover, we do have very clear empirical evidence at this point that some form of liberal democracy with a mixed economy is the best system we’ve got so far. One can reasonably debate whether Canada is doing better or worse than France, or whether the system in Denmark could really be scaled to the United States, or just what the best income tax rates are; but there is a large, obvious, and important difference between life in a country like Canada or Denmark and life in a country like Congo or Afghanistan.

Indeed, perhaps there is no better pair to compare than North and South Korea: Those two countries are right next to each other, speak the same language, and started in more or less the same situation; but the south got good institutions and the north got bad ones, and now the difference between them couldn’t be more stark. (Honestly, this is about as close as we’re ever likely to get of a randomized controlled experiment in macroeconomics.)

People in South Korea now live about as well as some of the happiest places in the world; their GDP per capita PPP is about $65,000 per year, roughly the same as Canada. People in North Korea live about as poorly as it is possible for humans to live, subject to totalitarian oppression and living barely above subsistence; their GDP per capita PPP is estimated to be $600 per year—less than 1% as much.

The institutions of South Korea are just that much better.

Indeed, there’s one particular aspect of good institutions that seems really important, yet is actually kind of hard to justify in act-utilitarian terms:

Why is freedom good?

A country’s level of freedom is almost perfectly correlated with its overall level of happiness and development. (Yes, even on this measure, #ScandinaviaIsBetter.)

But why? In theory, letting people do whatever they want could actually lead to really bad outcomes—and indeed, occasionally it does. There’s even a theorem that liberty is incompatible with full Pareto-efficiency. But all the countries with the happiest people seem to have a lot of liberty, and indeed the happiest ones seem to have the most. How come?

My answer:

Personal liberty is a technology for heuristic utility maximization.

In the ideal case, we wouldn’t really need personal liberty; you could just compel everyone to do whatever is optimal all the time, and that would—by construction—be optimal. It might even be sort of nice: You don’t need to make any difficult decisions, you can just follow the script and know that everything will turn out for the best.

But since we don’t know what the optimal choice is—even in really simple cases, like what you should eat for lunch tomorrow—we can’t afford to compel people in this way. (It would also be incredibly costly to implement such totalitarian control, but that doesn’t stop some governments from trying!)

Then there are disagreements: What I think is optimal may not be what you think is optimal, and in truth we’re probably both wrong (but one of us may be less wrong).

And that’s not even getting into conflicts of interest: We aren’t just lacking in rationality, we’re also lacking in benevolence. Some people are clearly much more benevolent than others, but none of us are really 100% selfless. (Sadly, I think some people are 100% selfish.)

In fact, this is a surprisingly deep question:

Would the world be better if we were selfless?

Could there be actually some advantage in aggregate to having some degree of individual self-interest?

Here are some ways that might hold, just off the top of my head:

• Partial self-interest supports an evolutionary process of moral and intellectual development that otherwise would be stalled or overrun by psychopaths—see my post on Rousseaus and Axelrods
• Individuals have much deeper knowledge of their own preferences than anyone else’s, and thus can optimize them much better. (Think about it: This is true even of people you know very well. Otherwise, why would we ever need to ask our spouses one of the most common questions in any marriage: “Honey, what do you want for dinner tonight?”)
• Self-interest allows for more efficient economic incentives, and thus higher overall productivity.

Of course, total selfishness is clearly not optimal—that way lies psychopathy. But some degree of selfishness might actually be better for long-term aggregate outcomes than complete altruism, and this is to some extent an empirical question.

Personal liberty solves a lot of these problems: Since people are best at knowing their own preferences, let people figure out on their own what’s good for them. Give them the freedom to live the kind of life they want to live, within certain reasonable constraints to prevent them from causing great harm to others or suffering some kind of unrecoverable mistake.

This isn’t exactly a new idea; it’s basically the core message of John Stuart Mill’s On Liberty (which I consider a good candidate for the best book every written—seriously, it beats the Bible by a light-year). But by putting it in more modern language, I hope to show that deontology and consequentialism aren’t really so different after all.

And indeed, for all its many and obvious flaws, freedom seems to work pretty well—at least as well as anything we’ve tried.