Arguing Absolute Velocities

CW: Analogies

You and a friend are arguing over a physics question: “You’re on a train speeding seventy miles per hour east, while you run 5 miles per hour west. How fast are you moving?”

That’s obvious, you think to yourself. The question says I’m running 5 miles per hour west, so I must be moving 5 miles per hour west. The extra stuff about the train is just there to confuse me.

Your friend is just as convinced: If the train’s moving 70 miles per hour east, and I’m running 5 miles per hour west, then my speed must be 65 miles per hour east, he reasons. I guess this guy must just be one of the slower kids at school. The next five minutes are spent in argument because you’re telepathic and can hear your friend’s mocking thoughts.

Then, because this was actually one of those dreams where you’re back in high school and don’t know any of the answers on the test, Galileo materializes in front of you.

“Forsake these notions of absolute velocity!” he booms. “Woe unto you, who have so quickly forgotten my doctrine of Galilean relativity! You are traveling 5 miles per hour west relative to the train, and 65 miles per hour east relative to the train tracks. You’re also going like a bajillion miles per hour around the sun.”

You are both deeply embarrassed, and have learned your lesson. You will never again forget that a measurement devoid of context is meaningless. What matters is the relationship between measurements. To talk about velocities, you need a reference point to compare to.

Galileo smiles at you both as he fades away into the abstract concept of experimentation.


It’s temptingly easy to argue absolute velocities.

Take Scott’s SSC post, “How Bad Are Things?”

This is also why I am wary whenever people start boasting about how much better we’re doing than back in the bad old days. That precise statement seems to in fact be true. [… But] I don’t think we have any idea how many people do or don’t have it pretty good.

Now, this is, strictly speaking, true. Just because the world’s improved, that doesn’t mean the average person’s life is good right now, because the question is wrong. Good or bad by what standard? How many people have it “Pretty good” depends almost entirely on what bar you pick, and not at all on how good people’s lives actually are.

Even if you think the right bar is obvious, it isn’t. You could put the bar for “a life worth living” at bare subsistence. After all, most people would rather be alive than dead, so it’s reasonable to assume their lives have some positive value. You could also set the bar at the average person’s quality of life. You could pick some “Acceptable” quality of living based on what you think constitutes a bare minimum. You could stop making me list examples since I’m running out. There’s infinitely many lines you could pick here, all at least somewhat arbitrary.

Or maybe you’re arguing about whether the world is fundamentally a good place or not. So imagine we find a moralometer, way out past Alpha Centauri, which can perfectly measure the amount of good in the universe. Having discovered this moralometer, you can now read off its precise output: The amount of good in the world is exactly equal to 1,276,642.

You might be a bit disappointed to hear that this number has changed exactly zero opinions on anything, because without having anything to compare it to, this number is meaningless.

This sounds pretty familiar, doesn’t it? We have two free variables, two questions we are trying to answer at the same time, but the answer to each depends on the other. “Is this possible world good” fails to be meaningful. Even if we agree on every ethical question and have zero disagreements about the state of the world, we haven’t set a reference point for what’s “Good.”

So the question of whether a possible world is good might be a meaningless one parsed literally. But nobody parses the question literally. Nobody tries to calculate the total amount of good before comparing it to a predetermined standard to see if it’s above or below it.

No, the truth is much worse. As soon as you’re discussing whether something is “Good” or “Bad” instead of “Better” or “Worse,” you’ve already failed. As soon as you start to argue about whether a policy, a choice, or anything else would be “Good,” you’ve left a free variable in the equations, and that way lies confusion.

Your subconscious is far better at tricking you than you give it credit for. Give it a single opening, leave a single definition unspecified, and it will immediately grasp for any positive affect that it can attach to help you win your argument; your brain is interested in winning arguments, even if they’re meaningless, not in being right. Without even noticing, your brain will seize on a reference point that lets you call your position “Good,” and anyone who dislikes your position will just as easily find a reference point to deny you this victory. After all, what could be more good than “Good” itself?


Just since I started writing this post, I’ve noticed at least half a dozen conversations falling into this failure mode. The most recent was a discussion on the US healthcare system where about thirty minutes in I realized with extreme embarrassment that the other person wasn’t actually disagreeing with me on whether some candidate’s particular healthcare plan was an improvement over the current US healthcare system—they just thought that this plan was worse than some other candidate’s healthcare plan.

There’s a couple suggestions I can make to help avoid this mistake.

The first is, beware of any words that convey , like “Good” or “Bad.” As soon as you hear these words come up in a discussion, start worrying. You will notice that the CBO score on bills does not include a section saying “this law contains an essence of goodness.”

Usually, the words you’re looking for are “Better” and “Worse.” “Democratic candidate# 247’s healthcare policy is better than #233’s” is far less likely to fall prey to this problem than “Democratic candidate #247’s healthcare policy is good.” None of this is to say that you can never use the words good/​bad (everyone knows what you mean when you say “Killing is bad”), but the situations where you’re disagreeing are rarely the same situations where you can afford even an ounce of vagueness.

At some point in the healthcare discussion laid out above, someone mentioned something along the lines of “Yeah, but better than the American healthcare system is a low bar to clear.” This is the smoking gun. As soon as you hear this, you know the conversation has gone off track.

There. Are. No. Objective. Bars. To figure out if a bar is high or low, you need another bar, and if you ask the first bar, it’s the other one that’s wrong. A bar can be bad at conveying information, i.e. “Passing this law would be better than starting a genocide,” but it can’t be wrong.

Even if you think the reference point you’re using is probably obvious, it is not. People will pick terrible reference points even when there’s a perfectly good reference point that the rest of the world uses; see Americans’ insistence that water must freeze at exactly 32 degrees. In my healthcare discussion, I thought that the reference point “The way things are right now” was obvious. It was not.

You’d better be damn sure that the reference point is obvious before you use it. Anything less clear than “Murder is bad” (reference point clearly intended to be not murdering people) should probably be avoided. Most importantly, if someone disagrees with a claim you’ve made along the lines “X is good/​bad,” proceed to set an explicit reference point.

After all, arguing absolute velocities is pretty bad.