"People use armed force all the time with their neighbors."
No, they really, really don't. Compared with either a). governments or b). people in the ancient world, violence nowadays is really rare. For governments, consider that, in 1900, it was common for a country to spend 10% of its GDP on its military; how many people do you know who spend 10% of their gross pre-tax income on weapons to fight their neighbors with? For people in the ancient world, consider that the murder rate for males before they reached age 25 in pre-agricultural societies was something like 30%; nowadays it's something like 1%.
"On a separate point, while the Nazis had some crazy beliefs, they still excelled in a number of important areas."
Agreed, but what I was saying was that none of these areas involved general intelligence, science, rationality or deliberative reasoning.
"So let's be glad they underrated rationality."
Agreed. My thesis in this post was that rationality, intelligence, and science are the most important factors on the level of a country, but not on the level of an individual. Hence, the Nazis, who were really irrational, succeeded at taking over Germany, but then failed at taking over the world largely through irrational stupidity.
Hence, the Nazis, who were really irrational, succeeded at taking over Germany, but then failed at taking over the world largely through irrational stupidity.
Certainly, sufficiently great (superhuman) rationality and intelligence could have taken over the world. But I'm not convinced that a group of sane, rational, intelligent mere humans at the head of Nazi Germany had a high probability of conquering the whole world (which would include the USA). The Nazis already did much better than could be expected on average for humans. How much better than that could you be, if you were in their place? What would you do exactly?
As Eliezer and many others on Less Wrong have said, the way the human species rose to dominate the Earth was through our intelligence- and not through our muscle power, biochemical weapons, or superior resistance to environmental hazards. Given our overwhelming power over other species, and the fact that many former top predators are now extinct or endangered, we should readily accept that general intelligence is a game-changing power on the species level.
Similarly, one of the key ingredients in the birth of the modern era was the discovery of science, and its counterpart, the discovery of the art of Traditional Rationality. Armed with these, the nations of Western Europe managed to dominate the entire rest of the world, even though, when they began their explorations in the 15th century, the Chinese were more advanced in many respects. Given how Western Europe, and the cultures derived from it, has so completely surpassed the rest of the world in terms of wealth and military might, we should readily accept that science and rationality is a game-changing power on the civilization level.
However, neither of these imply that intelligence, science, and rationality, as a practical matter, are the best way to get things done by individual people operating in the year 2009. We can easily see that many things which work on the species level, or the civilization level, do not work for individuals and small groups. For instance, until the discovery of nuclear weapons, armed conflict was often a primary means of settling disputes between nation-states. However, if you tried to settle your dispute with your neighbor, or your company's dispute with its competitor, using armed force, it would achieve nothing except getting you thrown in prison.
People are crazy and the world is mad, but it does not necessarily follow that we should try to solve our own problems primarily by becoming more sane. Plenty of people achieve many of their goals despite being completely nuts. Adolf Hitler, for example, achieved a large fraction of his (extremely ambitious!) goals, despite having numerous beliefs that most of us would recognize as making no sense whatsoever.
We know, as a matter of historical fact, that Adolf Hitler and his Nazi Party, despite being generally incompetent, unintelligent, irrational, superstitious and just plain insane, managed to take over a country of tens of millions of people from nothing, in the span of fifteen years. So far as I am aware, no group of people has managed to achieve anything even remotely similar using, not only rationality, but any skill involving deliberative thought, as opposed to skills such as yelling at huge crowds of people. However, it is a corollary to the statement that no one knows what science doesn't know that no one knows what history doesn't know, so it is entirely possible, perhaps likely, that there is something I am overlooking. To anyone who would assert that intelligence, science or rationality is the Ultimate Power, not just on the level of a species or civilization, but on the level of an individual or small group, let them show that their belief is based in reality.