When people are bad at math, they know it, because they get the wrong answers on tests. But when people are bad at open-mindedness, they don’t know it. In fact they tend to think the opposite. Remember, it’s the nature of fashion to be invisible. It wouldn’t work otherwise. Fashion doesn’t seem like fashion to someone in the grip of it. It just seems like the right thing to do. It’s only by looking from a distance that we see oscillations in people’s idea of the right thing to do, and can identify them as fashions.

Time gives us such distance for free. Indeed, the arrival of new fashions makes old fashions easy to see, because they seem so ridiculous by contrast. From one end of a pendulum’s swing, the other end seems especially far away.

To see fashion in your own time, though, requires a conscious effort. Without time to give you distance, you have to create distance yourself. Instead of being part of the mob, stand as far away from it as you can and watch what it’s doing. And pay especially close attention whenever an idea is being suppressed. Web filters for children and employees often ban sites containing pornography, violence, and hate speech. What counts as pornography and violence? And what, exactly, is “hate speech?” This sounds like a phrase out of 1984.

Labels like that are probably the biggest external clue. If a statement is false, that’s the worst thing you can say about it. You don’t need to say that it’s heretical. And if it isn’t false, it shouldn’t be suppressed. So when you see statements being attacked as x-ist or y-ic (substitute your current values of x and y), whether in 1630 or 2030, that’s a sure sign that something is wrong. When you hear such labels being used, ask why.

Especially if you hear yourself using them. It’s not just the mob you need to learn to watch from a distance. You need to be able to watch your own thoughts from a distance. That’s not a radical idea, by the way; it’s the main difference between children and adults. When a child gets angry because he’s tired, he doesn’t know what’s happening. An adult can distance himself enough from the situation to say “never mind, I’m just tired.” I don’t see why one couldn’t, by a similar process, learn to recognize and discount the effects of moral fashions.

You have to take that extra step if you want to think clearly. But it’s harder, because now you’re working against social customs instead of with them. Everyone encourages you to grow up to the point where you can discount your own bad moods. Few encourage you to continue to the point where you can discount society’s bad moods.

How can you see the wave, when you’re the water? Always be questioning. That’s the only defence. What can’t you say? And why?

Paul Graham, Hackers & Painters: Big Ideas from the Computer Age, Sebastopol, California, 2004, pp. 48–49