Wittgenstein’s Ruler (McCarthy’s Maxim)

[Updated 10/12/2016]

I was originally going to call this site “Wittgenstein’s Ruler.”

What Wittgenstein’s Ruler says is, “Unless you have confidence in the ruler’s reliability, if you use a ruler to measure a table you may also be using the table to measure the ruler.” It’s a fun metaphor about the role of measurement and observation in how we learn and think. With enough data on our political leanings, our educational background, and a few other factors, it’s easy to extrapolate what we think about any particular issue with accuracy.

Nassim Taleb, author of Fooled by Randomness, coined the term Wittgenstein’s Ruler, but the concept itself is derived from the writings of early 20th-century philosopher Ludwig Wittgenstein, who has always been a favorite of mine. I believe the reference from Wittgenstein where Taleb adopted the expression is on p. 191 of the Philosophical Investigations, which says:

One judges the length of a rod and may look for and find some method of judging it more exactly or more reliably. So – you say – what is judged here is independent of the method of judging it. What length is cannot be defined by the method of determining length. To think like this is a mistake. . . . And one wants to compare ‘ever more accurate measurements of length’ with the nearer and nearer approach to an object. But in certain cases it is, and in certain cases it is not, clear what ‘approaching nearer to the length of the object” means.

Wittgenstein’s writing can be fairly obtuse, but what this says to me is that the object that’s doing the measuring determines the output of measurement.

My preferred articulation of the issue is this: Most of the time, people’s observations about something else reveal more about the observer than what’s being observedI’m not sure if this is the same concept that Wittgenstein or Taleb are driving at, but it’s a central focus of my thinking. So at the risk of narcissism, I’ll call this McCarthy’s Maxim.

Taleb calls this an authority question, but to me, it’s more of a critical thinking question. An essay by Paul Krugman on gun control will be more instructive on what an exceedingly intelligent, east coast liberal thinks about guns than the issue of gun control itself. An essay by Paul Krugman on the Japanese recession will say more about what a traditional Keynesian thinks about economic policy than the nuances of the Japanese recession. And so on.

That’s what most of us do. We bring our biases everywhere we go and apply to them to every problem.

The expression, “To a man with a hammer everything looks like a nail,” basically says the same thing as McCarthy’s Maxim. The hammers are our pre-existing beliefs, which are basic inputs we acquire from genetics and environment The nails are the simple, predictable outputs we produce based on those inputs.

To use a couple of easy examples: If we know that someone is a 60-year-old, white male, practicing Baptist from rural Alabama, we could predict with high probability whether that person has a favorable opinion of President Obama. If we know that someone is a 32-year-old, Hispanic, liberal arts graduate from Massachusetts, we could predict with high probability whether that person has a favorable opinion of Donald Trump.

That’s all too easy. Yet few of us stop to ponder how terribly predictable we are in our own beliefs. When we explain why we believe what we believe, it’s usually confabulation. Most Mormons are Mormons because their parents were Mormons. Most Muslims are Muslims because their parents were Muslims. And if your beliefs aren’t a reflection of your family, they’re probably a reflection of your peer group. Once someone locks in a set of beliefs, it doesn’t matter what new inputs are produced, the output is always the same.

Most of us are just hammers looking for nails.

Physics, chemistry, evolutionary biology, economics, philosophy, alchemy, astrology, Roman Catholicism, politics, and phrenology are all different “tools” that people have used of to answer hard questions.

Which tool you use to solve any particular problem says something about you. If you use the same tool every time, it makes you very predictable. If you use classic liberal or classic conservative ideology to scrutinize Donald Trump’s presidential campaign, you’re not likely to be very interesting. If you use superstring theory to assess Donald Trump’s presidential campaign, you would probably be interesting, but you might not be very useful. If you analyzed Donald Trump’s presidential campaign under the lens of evolutionary biology, economics, and game theory, then you’d have a few different ways to explain what was happening.

It is possible to expand the toolkit, so to speak. And if we want to get good answers to different kinds of questions, it’s essential to expand our toolkits. Expanding the toolkit merely requires us to read about lots of different stuff and to know that there are many different ways to approach a problem.

But an expansive toolkit doesn’t do you any good if aren’t willing to adjust your own biases to reflect new circumstances, rather than try to fit new circumstances into your old biases. That’s the essence of Wittgenstein’s Ruler, McCarthy’s Maxim, and its corollaries: The ability to adjust one’s thinking to new problems.

Regardless of what this blog is named, that is the main theme of this blog.