There's an old aphorism that those who don't learn from history are doomed to repeat it.

Unfortunately, there's another, related one, to the effect that the main thing we learn from history is that we don't learn from history.

To digress for just a moment, scientists and engineers, and rationalists in general, try to expand their knowledge about the world by formulating theories, performing experiments to test them, gathering data, and drawing conclusions about them. But such experiments have to be controlled--that is, they have to be structured in such a way as to allow a focus on a single aspect of it. If one gets different results from different cases, but there are multiple factors involved, there's no way to tell which factor caused the difference, and the experiment isn't particularly useful.

This is what makes history so problematic for such people--it's not possible to do controlled experiments. All that we can do is dig through the entrails of events, capture what we think (and being human, often hope) were the most significant aspects of them, try to draw conclusions about why they occurred from those aspects, and then attempt (often in vain) to make predictions about the effects of future events. But we can never know for sure which factors were the most important ones, because they can't be tested in isolation--with history, what you see is what you get, and there's no rewind button.

Those who make and pontificate about space policy are largely such people, so it's all the more frustrating to them that it's so difficult to come to a consensus on what's worked in the past, and what will work in the future. Sadly, absent a large body of data, it's actually very hard to learn from history, a fact that's demonstrated by this article, in which, in the face of turbulent times in space policy, a number of disparate viewpoints are offered about NASA's future direction. Some of those viewpoints are ones that I've expressed in this space, and others, for many years.

The disparity of viewpoints arises from two sources, that often get intermingled. The first, and a point that I've made repeatedly, both here and in other fora, is that it's difficult to get a consensus on means when we can't even agree on ends. Not all of the people quoted in the article desire the same thing from a space program, so it's not surprising that it's hard to get agreement from them on how to go about getting it.

The second source of dispute is that, even if two people agree on an end goal (e.g., large-scale space colonization), it's not at all clear what the best government policy might be to achieve that goal, because of the scant historical basis for past successes (and because of the first factor, it's difficult to even get agreement on what constitutes a success).

Everyone views history through the lens of his or her own experience and prejudices. William Hartmann, quoted in the article, is a scientist. He is also, apparently, knowingly or otherwise, a transnationalist.

Hartmann thinks international governmental cooperation is the best way to get humans to the Moon or Mars. Eventually, if a proper framework can be set, commercialization could and should blossom, Hartmann figures...

...Hartmann, whose latest book is "A Traveler's Guide to Mars" (Workman Publishing Company, 2003), worries whether any possible new Bush directive on human spaceflight would serve long-term global interests, however.

"Do we want to hand over this unique moment and all those resources to a bunch of deregulated CEO's with their short-term, self-serving accountant mentality?" asks Hartmann. "Or can we design a strategy that fosters a better global payoff for our grandchildren?"

He believes that the primary, if not sole, purpose of having a space program is for science (though he's apparently willing to allow some exploitation of resources, as long as it's done under the auspices of some appropriate international bureaucracy). He also believes that doing such a program internationally is not just a good idea because we can share the expense of such an endeavor, but because international programs are somehow more noble, and higher of purpose than national ones. He doesn't want to sully the pristine, untrammeled scientific preserve of space with the greed of unbridled capitalism.

For him, the lesson of history is that we once had a space program that was paid for by all the people, and that it sent men to the moon "in peace, for all mankind." Somehow, we lost that noble spirit, and frittered away all of our capability to even repeat it, let alone go on to the next unexplored world. It was a failure of political leadership, because the president that launched us on such a grand adventure was assassinated. Now, he can only hope for another president of such vision.

But such a lesson is a mistaken one, for a number of reasons. The first, of course, is that, as I've noted before, the legend of the visionary space president isn't true. JFK pursued Apollo for temporary political reasons, and for him, it wasn't a space program--it was a national security and propaganda program. Were space, or science, the point, we wouldn't have waited until the last flight before we sent an actual scientist to the moon (and it should be noted that, on this coming Sunday, it will be the thirty-one years since man last walked on our sister orb).

But the second reason is that, even if it were true, it would have been an anomalous event, not a normal one. Historically, governments rarely expend vast amounts of national resources on exploration for exploration's sake, or for science. Isabella didn't pay for Columbus' voyages out of intellectual curiousity--she was seeking better trade routes for known riches.

As much as Dr. Hartmann disdains it, abundant evidence from history should teach him that greed is one of the primary human motivators, the other being fear. Apollo was an example of the latter. Only when we stop living in a past that never was, and embrace and harness the former, will we start to truly make the new frontier a significant part of human history and make true exploration of the cosmos affordable and sustainable. Let us hope that, to the degree that the Bush administration is reconsidering space policy now, it understands that lesson as well.

But such experiments have to be controlled--that is, they have to be structured in such a way as to allow a focus on a single aspect of it. If one gets different results from different cases, but there are multiple factors involved, there's no way to tell which factor caused the difference, and the experiment isn't particularly useful.

Arrgh! This has got to be one of the biggest blind spots in science education! While the idea of controlled experiments is spot on, the belief that experiments can only change one variable at a time is straight out of the nineteenth century. The greatest statisticians of the twentieth century, men like Fisher and Yates, when to great lengths to show how well-designed experiments could test multiple factors reliably and economically. Unfortunately, the usual one semester of statistics that many of our scientists and engineers get as undergrads doesn't get them to this radical idea.

The problem with public policy isn't just the confounding of factors (though that's bad), it's that by its very nature, it's not an experiment under controlled conditions. Instead, it's what we call an observational study. And a good rule of thumb is that observational studies--unlike controlled experiments--can never prove cause-and-effect relationships.

"He believes that the primary, if not sole, purpose of having a space program is for science (though he's apparently willing to allow some exploitation of resources, as long as it's done under the auspices of some appropriate international bureaucracy). He also believes that doing such a program internationally is not just a good idea because we can share the expense of such an endeavor, but because international programs are somehow more noble, and higher of purpose than national ones. He doesn't want to sully the pristine, untrammeled scientific preserve of space with the greed of unbridled capitalism."

Maybe Hartman is more influenced by Star Trek than JFK?

slimedog's got it. Pure variable isolation isn't necessary, only desirable. Also, science does not necessarily rely only on experimentation. Several very well developed sciences, such as astronomy and biology, would be quite insubstantial if that were the case.