Part 2 (1/2)

One way to tell how good people are at empathy is to watch them explain a technical matter to someone without a technical background. We probably all know people who, though otherwise smart, are just comically bad at this. If someone asks them at a dinner party what a programming language is, they'll say something like ”Oh, a high-level language is what the compiler uses as input to generate object code.” High-level language? Compiler? Object code? Someone who doesn't know what a programming language is obviously doesn't know what these things are, either.

Part of what software has to do is explain itself. So to write good software you have to understand how little users understand. They're going to walk up to the software with no preparation, and it had better do what they guess it will, because they're not going to read the manual. The best system I've ever seen in this respect was the original Macintosh, in 1984. It did what software almost never does: it just worked.

Source code, too, should explain itself. If I could get people to remember just one quote about programming, it would be the one at the beginning of Structure and Interpretation of Computer Programs.

Programs should be written for people to read, and only incidentally for machines to execute.

Figure 2-2. Piero della Francesca's Federico da Montefeltro, 1465-66 (detail).

You need to have empathy not just for your users, but for your readers. It's in your interest, because you'll be one of them. Many a hacker has written a program only to find on returning to it six months later that he has no idea how it works. I know several people who've sworn off Perl after such experiences.

Lack of empathy is a.s.sociated with intelligence, to the point that there is even something of a fas.h.i.+on for it in some places. But I don't think there's any correlation. You can do well in math and the natural sciences without having to learn empathy, and people in these fields tend to be smart, so the two qualities have come to be a.s.sociated. But there are plenty of dumb people who are bad at empathy too.

So, if hacking works like painting and writing, is it as cool? After all, you only get one life. You might as well spend it working on something great.

Unfortunately, the question is hard to answer. There is always a big time lag in prestige. It's like light from a distant star. Painting has prestige now because of great work people did five hundred years ago. At the time, no one thought these paintings were as important as we do today. It would have seemed very odd to people in 1465 that Federico da Montefeltro, the Duke of Urbino, would one day be known mostly as the guy with the strange nose in a painting by Piero della Francesca.

So while I admit that hacking doesn't seem as cool as painting now, we should remember that painting itself didn't seem as cool in its glory days as it does now.

What we can say with some confidence is that these are the glory days of hacking. In most fields the great work is done early on. The paintings made between 1430 and 1500 are still unsurpa.s.sed. Shakespeare appeared just as professional theater was being born, and pushed the medium so far that every playwright since has had to live in his shadow. Albrecht Durer did the same thing with engraving, and Jane Austen with the novel.

Over and over we see the same pattern. A new medium appears, and people are so excited about it that they explore most of its possibilities in the first couple generations. Hacking seems to be in this phase now.

Painting was not, in Leonardo's time, as cool as his work helped make it. How cool hacking turns out to be will depend on what we can do with this new medium.

Chapter 3. What You Can't Say.

Have you ever seen an old photo of yourself and been embarra.s.sed at the way you looked? Did we actually dress like that? We did. And we had no idea how silly we looked. It's the nature of fas.h.i.+on to be invisible, in the same way the movement of the earth is invisible to all of us riding on it.

What scares me is that there are moral fas.h.i.+ons too. They're just as arbitrary, and just as invisible to most people. But they're much more dangerous. Fas.h.i.+on is mistaken for good design; moral fas.h.i.+on is mistaken for good. Dressing oddly gets you laughed at. Violating moral fas.h.i.+ons can get you fired, ostracized, imprisoned, or even killed.

If you could travel back in a time machine, one thing would be true no matter where you went: you'd have to watch what you said. Opinions we consider harmless could have gotten you in big trouble. I've already said at least one thing that would have gotten me in big trouble in most of Europe in the seventeenth century, and did get Galileo in big trouble when he said it-that the earth moves.

Nerds are always getting in trouble. They say improper things for the same reason they dress unfas.h.i.+onably and have good ideas. Convention has less hold over them.

It seems to be a constant throughout history: in every period, people believed things that were just ridiculous, and believed them so strongly that you would have gotten in terrible trouble for saying otherwise.

Is our time any different? To anyone who has read any amount of history, the answer is almost certainly no. It would be a remarkable coincidence if ours were the first era to get everything just right.

It's tantalizing to think we believe things that people in the future will find ridiculous. What would someone coming back to visit us in a time machine have to be careful not to say? That's what I want to study here. But I want to do more than just shock everyone with the heresy du jour. I want to find general recipes for discovering what you can't say, in any era.

3.1. The Conformist Test

Let's start with a test: do you have any opinions that you would be reluctant to express in front of a group of your peers?

If the answer is no, you might want to stop and think about that. If everything you believe is something you're supposed to believe, could that possibly be a coincidence? Odds are it isn't. Odds are you just think whatever you're told.

The other alternative would be that you independently considered every question and came up with the exact same answers that are now considered acceptable. That seems unlikely, because you'd also have to make the same mistakes. Mapmakers deliberately put slight mistakes in their maps so they can tell when someone copies them. If another map has the same mistake, that's very convincing evidence.

Like every other era in history, our moral map almost certainly contains mistakes. And anyone who makes the same mistakes probably didn't do it by accident. It would be like someone claiming they had independently decided in 1972 that bell-bottom jeans were a good idea.

If you believe everything you're supposed to now, how can you be sure you wouldn't also have believed everything you were supposed to if you had grown up among the plantation owners of the pre-Civil War South, or in Germany in the 1930s-or among the Mongols in 1200, for that matter? Odds are you would have.

Back in the era of terms like ”well-adjusted,” the idea seemed to be that there was something wrong with you if you thought things you didn't dare say out loud. This seems backward. Almost certainly, there is something wrong with you if you don't think things you don't dare say out loud.

3.2. Trouble

What can't we say? One way to find these ideas is simply to look at things people do say, and get in trouble for.

Of course, we're not just looking for things we can't say. We're looking for things we can't say that are true, or at least have enough chance of being true that the question should remain open. But many of the things people get in trouble for saying probably do make it over this second, lower threshold. No one gets in trouble for saying that 2 + 2 is 5, or that people in Pittsburgh are ten feet tall. Such obviously false statements might be treated as jokes, or at worst as evidence of insanity, but they are not likely to make anyone mad. The statements that make people mad are the ones they worry might be believed. I suspect the statements that make people maddest are those they worry might be true.

If Galileo had said that people in Padua were ten feet tall, he would have been regarded as a harmless eccentric. Saying the earth orbited the sun was another matter. The church knew this would set people thinking.

Certainly, as we look back on the past, this rule of thumb works well. A lot of the statements that got people in trouble seem harmless now. So it's likely that visitors from the future would agree with at least some of the statements that get people in trouble today. Do we have no Galileos? Not likely.

To find them, keep track of opinions that get people in trouble, and start asking, could this be true? Ok, it may be heretical (or whatever modern equivalent), but might it also be true?

3.3. Heresy

This won't get us all the answers, though. What if no one happens to have gotten in trouble for a particular idea yet? What if some idea would be so radioactively controversial that no one would dare express it in public? How can we find these too?

Another approach is to follow that word, heresy. In every period of history, there seem to have been labels that got applied to statements to shoot them down before anyone had a chance to ask if they were true or not. ”Blasphemy,” ”sacrilege,” and ”heresy” were such labels for a good part of Western history, as in more recent times ”indecent,” ”improper,” and ”un-American” have been. By now these labels have lost their sting. They always do. By now they're mostly used ironically. But in their time, they had real force.

The word ”defeatist,” for example, has no particular political connotations now. But in Germany in 1917 it was a weapon, used by Ludendorff in a purge of those who favored a negotiated peace. At the start of World War II it was used extensively by Churchill and his supporters to silence their opponents. In 1940, any argument against Churchill's aggressive policy was ”defeatist.” Was it right or wrong? Ideally, no one got far enough to ask that.

We have such labels today, of course, quite a lot of them, from the all-purpose ”inappropriate” to the dreaded ”divisive.” In any period, it should be easy to figure out what such labels are, simply by looking at what people call ideas they disagree with besides untrue. When a politician says his opponent is mistaken, that's a straightforward criticism, but when he attacks a statement as ”divisive” or ”racially insensitive” instead of arguing that it's false, we should start paying attention.

So another way to figure out which of our taboos future generations will laugh at is to start with the labels. Take a label-”s.e.xist,” for example-and try to think of some ideas that would be called that. Then for each ask, might this be true?

Just start listing ideas at random? Yes, because they won't really be random. The ideas that come to mind first will be the most plausible ones. They'll be things you've already noticed but didn't let yourself think.

In 1989 some clever researchers tracked the eye movements of radiologists as they scanned chest images for signs of lung cancer.