I will hesitate to wear these rosy glasses. The West has had somewhat peaceful 60 years, that's about it. See how liberal countries like Sweden suddenly close because of Syria? Revenge, hatred, and love are perennial notions, and they will always be part of the human psyche. The battle between good and evil has no ultimate victors or losers. Rationality does not explain what is at work here, it is not a deep enough human motivation.

If this sounds unconvincing, the Buddha and Christ preceded Hitler. Ashoka established a chain of veterinary hospitals in India in 360 BC, proclaiming that animals required equal treatment as humans do. [1] Are we "better" than these humanitarians?

Another example: India had no slavery in Greek times, and now has the largest number of slaves in history. [2] [3] I think similar cycles of rises and downfall can be seen in all the great civilizations, Egypt, Mesopotamia, China etc.

I don't know the answer, but history does not seem to be a linear progression from barbarism to civilization. It seems more like revisiting the same questions on good and evil, each time with more potent technology. The morality is the same, the technology progresses.

[1] https://en.wikipedia.org/wiki/Ashoka#As_administrator

[2] http://legacy.fordham.edu/halsall/ancient/arrian-bookVIII-In... paragraph X

[3] https://en.wikipedia.org/wiki/Slavery#Distribution

Sweden is almost 5,000 km away from Syria. What specifically relates these two countries in your comment?

Oh, my point was that countries liberal at one point in time may close down later. The original poster was trying to say that conservative -> liberal is the trend of history. I was trying to argue that the back-edge is also possible, and witnessed often in history. Even for long-term trends, the general direction seems not all that clear.

Why downvotes?

While we may not have reached the depraved depths of some past civilizations, the 20th century was by far the bloodiest century in human history (Lenin, Stalin, Hitler, Pol Pot, Kim il-sung, Kim Jong-il, Kim Jong-un, ...) The vector is not towards any higher morals.

"There are more slaves today than were seized from Africa in four centuries of the trans-Atlantic slave trade." http://ngm.nationalgeographic.com/ngm/0309/feature1/

Torture is alive and well.

Forgiveness is the key for all of us. But this does not bypass justice. Forgiveness can not simply be sweeping atrocities under the rug. A price has to be payed. Fortunately it was and forgiveness is offered freely to whoever wants it. But generally few seem to care.

Although the 20th century wasn't peaceful by any means, there is some evidence that violence has decreased proportionally to the population. Steve Pinker's well researched The Better Angels of Our Nature is a good tome on the subject: https://en.wikipedia.org/wiki/The_Better_Angels_of_Our_Natur...

One big problem with using these stats as a morality vector is that they are not adjusted for population growth.

Its difficult to measure if brutality, genocide, tortures is waxing or waning, but its long way from being non-existant.

The 20'th century was probably the bloodiest only because of advanced technology.

Just imagine Attila the Hun with tanks and nukes.

Genocide has always been a thing. The Romans wiped out god knows how many tribes. I'd say a 100% death rate for a particular tribe or nation is much bloodier than, say, 50%, wouldn't you?

I would say both are beyond the threshold of horrifying. For someone to say these don't exist anymore is mind boggling.

> I think, generally speaking, society's morals have improved over the ages (glossing over the whole "what is morality?" debate — but you get the gist of what I'm trying to say)

I think you're bordering on the tautological there. To say society's morals have improved demands an eternal natural law to evaluate it against. As society's view of what is the natural law changes, it's difficult to say whether we've improved rather than simply changed.

Fair point, and it's something I stumbled over a bit in my original post. I should have used a more objective definition of "rationality" — something that is independent of anyone's particular philosophy on morality. I believe if you Google "collective rationality", this has already been somewhat formalized, but I don't know too much about the theory other than the general idea behind it.

Most concepts of modern rationality --at least the kind you're talking about-- presume some form of materialism, which is a giant jump to conclusions in a discussion about morality. This is especially interesting if we want to talk about objective concepts and measurements.

Who decides what's objective? Do we decide that collectively? Are we collectively rational enough to figure out if we're collectively rational enough to decide?

I don't think that most crime will be considered more of a mental illness, unless we're willing to consider selfishness as a mental problem too. Serial murderers may be getting treatment, but a lot of crimes (especially white collar) happen out of plain old willingness to pursue your own interests at the expense of others. There will need to be a form of enforcement that will keep people in line - the will to game the system seems to be far too common to consider it as an abnormality.

Then if you take into account that with large populations people seem to follow incentives quite strictly. Nobody can recall they didn't buy bottle of jack because of additional 5% tax. But that tax increase shows in alcohol consumption statistics.

But I'm not advocating overly harsh punishments either. At some point you hit diminishing returns.

"Can a country's democratic institutions survive when the primary emotion underlying so much of its social policy, and determining the allocation of a sizable proportion of its annual revenues, is revenge?...We will in short become a community in name only, an increasingly atomized continent in which the primary role of government is to instill fear of the law rather than respect for its integrity."

Good book on the topic of punishment vs. rehabilitation:

http://www.amazon.com/American-Furies-Punishment-Vengeance-I...

I think you misinterpret collective rationality, as Weirich never try's explain a historical progression for western morality.

And as mentioned there have been other cultures with strong rational traditions that have come to far different moral conclusions than today - e.g. soviet/communism, Islamic societies,etc.. Pure reason thought doesn't go one direction, it can take you to very different and uncomfortable places.

"Collective rationality" by itself feels a bit circular because it doesn't come with an absolute way to measure how rational a conclusion is that doesn't ultimately loop back to what we've concluded now.

Perhaps if you used the idea to compare against some abstract scale (like, for the sake of argument, utilitarianism) it would be an interesting conclusion but without it it feels like "what's popular is right because what's right is popular", and popularity really isn't a great measure of quality[1].

A big part of the problem is that this vaguely teleological process, to the extent it exists, is almost certainly not monotonic. Even if we agree to, hmm, eventual consistency, it's hard to believe things are always improving and never getting worse. But this means that the idea all of a sudden has surprisingly weak predictive power. It's easy to analyze history and come up with an argument for many trends we like, even contradictory ones. We can say that, hey, there's this general trend, but we took a step back in the 1950s and we took a step back during the War in Iraq and hey, maybe we're taking a step back now, but the global process exists.

Honestly, it reeks a bit of rationalization.

A concrete example I've thought about: freedom of speech. It's a value I, like many others here, hold dear. And you know, I can make a pretty strong case that we're moving towards more and more freedom of speech both legally and culturally. The government censors less and less, our neighbors tolerate more deviance and obscenity and lots of taboo topics aren't taboo any more. Of course, some new topics become taboo every now and then, and people constantly clamor against freedom of speech, but on the whole we're getting freer and freer. On the face of it, this is a plausible argument.

But I've heard exactly the same reasoning but for ideas that, naturally, are at odds with freedom of speech, like certain notions of "human dignity" (which makes certain things unsayable). And hey, they can build a case just as well!

And perhaps I'm just seeing signal in noise. Taboos change but instead of progressing it's a cycle: old words that have been taboo for too long lose their sting while new ones acquire it. We can actually observe this with words describing less-favored positions like "secretary". It used to be that "secretary" was a perfectly reasonable job description; now we call them "executive assistants" and while "secretary" isn't a taboo per se it's certainly jarring. (There's a name for this cycle, actually, but I forget what it is.)

Honestly, on the whole, I think any strong view of "collective rationality" is, well, too strong. (Just like the efficient market hypothesis—a good point of comparison, in fact.) More importantly, regardless of how true it is as a general trend, I think there is way too much noise to use it to come to specific conclusions. Even with a general upward trend, the variance in what is and isn't taboo is going to dominate unless we have some other scale to value it on.

And, gratuitously, I'm going to link to my favorite of PG's essays which is pretty relevant to the topic if somewhat orthogonal to my point: "What You Can't Say"[2]. It's worth a read.

[1]: Second time today I'm linking to this comment, because it covers an idea I find quite powerful: https://news.ycombinator.com/item?id=10567962

[2]: http://www.paulgraham.com/say.html