Argument to Extreme Moderation

EssenseOfThought has already covered the way Rationality Rules plunges head-first into this fallacy, but I don’t think they truly captured how far he takes it. I mean, he said this with a straight face:

[2:53] The truth on the matter, however, as where it normally is, between the two extremes, and within this video I’m going to do my utmost best to show this to be the case.


According to Newtonian Mechanics, the International Space Station orbits the Earth because all mass has an attractive force associated with it. This causes two masses to accelerate towards each other, absent any external influence. The Earth’s acceleration towards the ISS is so weak that it can be safely ignored, and at any rate to someone standing on Earth it looks like the Earth alone is tugging on the ISS. As luck would have it, the ISS has a substantial velocity perpendicular to Earth’s average gravitational force vector. It is accelerated towards the Earth, but it travels so far horizontally that the distance it falls is approximately the same amount as the Earth’s surface curves away with it. To borrow Douglas Adams, the ISS is essentially throwing itself at the Earth and missing.

According to General Relativity, the ISS orbits the Earth because all mass causes curvature in space-time. There is no gravitational force between two objects, instead absent any external influence they only follow straight lines. A straight line through a curved space appears curved, or at least it does if the patch of space you’re standing on isn’t that curved itself. So why doesn’t the ISS just straight-line itself into the planet? Think of tossing a skateboard into the bowl of a skate park; while the skateboard usually winds up gently rocking in the bottom, there are also trajectories where you can launch it over the lip. This implies that if we could somehow partly disable friction, and your aim was supernaturally good, you can get the skateboard to neither rock at the bottom nor launch over the lip, but orbit around the bowl. As luck would have it, the ISS was precisely aimed to follow along the local space-time curvature, and more-or-less orbit around the Earth.

These two pictures of gravity could be no different. Both are wrong; GR depends on locality and realism, and we know one of those two is contrary to reality. So what theory is between them? What is part way between “a force pulls on matter” and “space-time is curved?”

We can go right down the line on this: what’s between “light travels infinitely fast” and “light has a finite speed?” Or “the Sun orbits the Earth” and “the Earth orbits the Sun?” Or “fossils were laid down during flood that happened 6,000 years ago” and “fossils were gradually laid down oven hundreds of millions of years?” Or “heat is a fluid” and “heat is the average motion of particles?” Even wave-particle duality, which might seem like an exception on the surface, falls into this pattern once you start delving into the details.

There’s nothing mysterious about why this is the case. It’s a good bet that there are four fundamental forces on your side of the fence, six types of both quarks and leptons, and that atoms are a thing. Reality seems to have some sort of consistency to it. When we sit down and try to work out that consistency, our explanations and descriptions will either perfectly describe that consistency, or they won’t. This implies one of two cases: there is either one description of reality that is as consistent as reality, or multiple descriptions which are equally consistent. Every other description will be less consistent, and therefore disfavoured. We add some additional constraints to these descriptions, such as internal consistency and compactness, which aren’t strictly necessary but help get around our physical limitations.

The upshot is that this leads to two ways for how our descriptions of reality develop. Either our preferred description is slowly refined over time

My answer to him was, “John, when people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together.” […]

In short, my English Lit friend, living in a mental world of absolute rights and wrongs, may be imagining that because all theories are wrong, the earth may be thought spherical now, but cubical next century, and a hollow icosahedron the next, and a doughnut shape the one after.

What actually happens is that once scientists get hold of a good concept they gradually refine and extend it with greater and greater subtlety as their instruments of measurement improve. Theories are not so much wrong as incomplete.

… or we hit the limits of refinement, and are forced to leap to an entirely different description of reality.

Kuhn’s version of how science develops differed dramatically from the Whig version. Where the standard account saw steady, cumulative “progress”, he saw discontinuities – a set of alternating “normal” and “revolutionary” phases in which communities of specialists in particular fields are plunged into periods of turmoil, uncertainty and angst. These revolutionary phases – for example the transition from Newtonian mechanics to quantum physics – correspond to great conceptual breakthroughs and lay the basis for a succeeding phase of business as usual. The fact that his version seems unremarkable now is, in a way, the greatest measure of his success.

In sum, reality is never found between two extremes, and there’s a sound philosophical argument that explains why. Rationality Rules is so desperate to play the argument to moderation fallacy, he’s lost his grip on reality.