January 2004
Have you ever seen an old photo of yourself and
been embarrassed 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 fashion 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 fashions too.
They’re just as arbitrary, and just as invisible to most people.
But they’re much more dangerous.
Fashion is mistaken for good design;
moral fashion is mistaken for good.
Dressing oddly gets you laughed at. Violating
moral fashions can get you fired, ostracized, imprisoned, or
even killed.

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.

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 what

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 a few 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.

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. [2]

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 people got in trouble for 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?

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 “unamerican” 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 — “sexist”, 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. [3] They found that even when the radiologists
missed a cancerous lesion, their eyes had usually paused at the site of it.
Part of their brain knew there was something there; it just
didn’t percolate all the way up into conscious knowledge.
I think many interesting heretical thoughts are already mostly
formed in our minds. If we turn off our self-censorship
temporarily, those will be the first to emerge.

Time and Space

If we could look into the future it would be obvious which
of our taboos they’d laugh at.
We can’t do that, but we can do something almost as good: we can
look into the past. Another way to figure out what we’re
getting wrong is to look at what used to be acceptable
and is now unthinkable.

Changes between the past and the present sometimes do represent
progress. In a field like physics,
if we disagree with past generations it’s because we’re
right and they’re wrong. But this becomes rapidly less true as
you move away from the certai