Update and reboot: Sam Harris has responded to my blog post reacting to his TED talk. In the initial version of this response-to-the-response-to-the-response-to-the-talk, I let myself get carried away with irritation at this tweet, and thereby contributed to the distraction from substantive conversation. Bad blogger.

In any event, Sam elaborates his position in some detail, so I encourage you to have a look if you are interested, although it didn’t change my mind on any issue of consequence. There are a number of posts out there by people who know what they are talking about and surely articulate it better than I do, including Russell Blackford and Julian Sanchez (who, one must admit, has a flair for titles), and I should add Chris Schoen.

But I wanted to try to clarify my own view on two particular points, so I put them below the fold. I went on longer than I intended to (funny how that happens). The whole thing was written in a matter of minutes — have to get back to real work — so grains of salt are prescribed.

First, the role of consensus. In formal reasoning, we all recognize the difference between axioms and deductions. We start by assuming some axioms, and the laws of logic allow us to draw certain conclusions from them. It’s not helpful to argue that the axioms are “wrong” — all we are saying is that if these assumptions hold, then we can safely draw certain conclusions.

A similar (although not precisely analogous) situation holds in other areas of human reason, including both science and morality. Within a certain community of like-minded reasoners, a set of assumptions is taken for granted, from which we can draw conclusions. When we do natural science, we assume that our sense data is more or less reliable, that we are not being misled by an evil demon, that simpler theories are preferable to complicated theories when all else is equal, and so forth. Given those assumptions, we can go ahead and do science, and when we disagree — which scientists certainly do — we can usually assume that the disagreements will ultimately be overcome by appeal to phenomena in the natural world, since as like-minded reasoners we share common criteria for adjudicating disputes. Of course there might be some people who refuse to accept those assumptions, and become believers in astrology or creationism or radical epistemological skepticism or what have you. We can’t persuade those people that they’re wrong by using the standards of conventional science, because they don’t accept those standards (even when they say they do). Nevertheless, we science-lovers can get on with our lives, pleased that we have a system that works by our lights, and in particular one that is pragmatically successful at helping us deal with the world we live in.

When it comes to morality, we indeed have a very similar situation. If we all agree on a set of starting moral assumptions, then we constitute a functioning community that can set about figuring out how to pass moral judgments. And, as I emphasized in the original post, the methods and results of science can be extremely helpful in that project, which is the important and interesting thing that we all agree on, which is why it’s a shame to muddy the waters by denying the fact/value distinction or stooping to insults. But I digress.

The problem, obviously, is that we don’t all agree on the assumptions, as far as morality is concerned. Saying that everyone, or at least all right-thinking people, really want to increase human well-being seems pretty reasonable, but when you take the real world seriously it falls to pieces. And to see that, we don’t have to contrast the values of fine upstanding bourgeois Americans with those of Hitler or Jeffrey Dahmer. There are plenty of fine upstanding people — you can easily find them on the internet! — who think that human well-being is maximized by an absolute respect for individual autonomy, where people have equal access to primary goods but are given the chance to succeed or fail in life on their own. Other people think that a more collective approach is called for, and it is appropriate for some people to cede part of their personal autonomy — for example, by paying higher taxes — in the name of the greater good.

Now, we might choose to marshall arguments in favor of one or another of these viewpoints. But those arguments would not reduce to simple facts about the world that we could in principle point to; they would be appeals to the underlying moral sentiments of the individuals, which may very well end up being radically incompatible. Let’s say that killing a seventy-year-old person (against their will) and transplanting their heart into the body of a twenty-year old patient might add more years to the young person’s life than the older person might be expected to have left. Despite the fact that a naive utility-counting would argue in favor of the operation, most people (not all) would judge that not to be moral. But what if a deadly virus threatened to wipe out all of humanity, and (somehow) the cure required killing an unwilling victim? Most people (not all) would argue that we should reluctantly take that step. (Think of how many people are in favor of involuntary conscription.) Does anyone think that empirical research, in neuroscience or anywhere else, is going to produce a quantitative answer to the question of exactly how much harm would need to be averted to justify sacrificing someone’s life? “I have scientifically proven that if we can save the life of 1,634 people, it’s morally right to sacrifice this one victim; but if it’s only 1,633, we shouldn’t do it.”

At bottom, the issue is this: there exist real moral questions that no amount of empirical research alone will help us solve. If you think that it’s immoral to eat meat, and I think it’s perfectly okay, neither one of us is making a mistake, in the sense that Fred Hoyle was making a mistake when he believed that conditions in the universe have been essentially unchanging over time. We’re just starting from different premises.

The crucial point is that the difference between sets of incompatible moral assumptions is not analogous to the difference between believing in the Big Bang vs. believing in the Steady State model; but it is analogous to believing in science vs. being a radical epistemological skeptic who claims not to trust their sense data. In the cosmological-models case, we trust that we agree on the underlying norms of science and together we form a functioning community; in the epistemological case, we don’t agree on the underlying assumptions, and we have to hope to agree to disagree and work out social structures that let us live together in peace. None of which means that those of us who do share common moral assumptions shouldn’t set about the hard work of articulating those assumptions and figuring out how to maximize their realization, a project of which science is undoubtedly going to be an important part. Which is what we should be talking about all along.

The second point I wanted to mention was the justification we might have for passing moral judgments over others. Not to be uncharitable, but it seems that the biggest motivation most people have for insisting that morals can be grounded in facts is that they want it to be true — because if it’s not true, how can we say the Taliban are bad people?

That’s easy: the same way I can say radical epistemological skepticism is wrong. Even if there is no metaphysically certain grounding from which I can rationally argue with a hard-core skeptic or a Taliban supporter, nothing stops me from using the fundamental assumptions that I do accept, and acting accordingly. There is a weird sort of backwards-logic that gets deployed at this juncture: “if you don’t believe that morals are objectively true, you can’t condemn the morality of the Taliban.” Why not? Watch me: “the morality of the Taliban is loathsome and should be resisted.” See? I did it!

The only difference is that I can only present logical reasons to support that conclusion to other members of my morality community who proceed from similar assumptions. For people who don’t, I can’t prove that the Taliban is immoral. But so what? What exactly is the advantage of being in possession of a rigorous empirical argument that the Taliban is immoral? Does anyone think they will be persuaded? How we actually act in the world in the face of things we perceive to be immoral seems to depend in absolutely no way on whether I pretend that morality is grounded in facts about Nature. (Of course there exist people who will argue that the Taliban should be left alone because we shouldn’t pass our parochial Western judgment on their way of life — and I disagree with those people, because we clearly do not share underlying moral assumptions.)

Needless to say, it doesn’t matter what the advantage of a hypothetical objective morality would be — even if the world would be a better place if morals were objective, that doesn’t make it true. That’s the most disappointing part of the whole discussion, to see people purportedly devoted to reason try to concoct arguments in favor of a state of affairs because they want it to be true, rather than because it is.

As heated global warming debates continue, scientists are also investigating ways to get our planet to cool off if the politicians can’t figure out how to reduce greenhouse gas emissions. The latest geoengineering scheme involves turning the world’s oceans into a giant bubble bath, with hundreds of millions of tiny bubbles pumped into the seas. This would increase the water’s reflectivity and bring down ocean temperatures, according to Harvard University physicist Russell Seitz. As the creative physicist said to the assembled crowd at an international meeting on geoengineering research: “Since water covers most of the earth, don’t dim the sun…. Brighten the water.”

Seitz explained that micro-bubbles already occur naturally, with bubbles under the ocean’s surface reflecting sunlight back into space and mildly brightening the planet. What Seitz imagines doing now is artificially pumping many more bubbles into the sea. These additional micro-bubbles would each be one five-hundredth of a millimeter and would essentially serve as “mirrors made of air.” The scientists say they could be created off boats by using devices that mix water supercharged with compressed air into swirling jets of water. “I’m emulating a natural ocean phenomenon and amplifying it just by changing the physics—the ingredients remain the same” [ScienceNOW], Seitz said.

Using a computer model that simulated how air, light, and water interacted, Seitz found that the micro-bubbles could have a profound cooling effect on our planet–suggesting that temperatures could cool as much as 5.4 degrees Fahrenheit. Along with the reflectivity of the added bubbles, previously published reports show that they may improve fuel efficiency of cargo ships, allowing them to virtually float on air [Treehugger]. Seitz has submitted a paper on the concept he calls “Bright Water” to the journal Climatic Change [ScienceNOW].

While Seitz is excited at the possibility of creating “bubble patches” to reduce the effects of global warming, it still needs to be seen what sort of infrastructure would be required to create these giant bubble baths. And as with all geoengineering schemes, there’s that pesky question of whether hacking planet-wide systems will have any pesky side effects.

Related Content:
80beats: Study: Climate Hacking Scheme Could Load the Ocean With Neurotoxins
80beats: With $4.5M of Pocket Change, Bill Gates Funds Geoengineering Research
80beats: If We Can’t Stop Emitting CO2, What’s Our Plan B?
80beats: Fighting Global Warming: Artificial Trees and Slime-Covered Buildings
DISCOVER: 5 Most Radical Ways to Squelch a Climate Crisis (slide show)

Image:Flickr/gog1_1gog

I found this incredible film by Cristobal Villa (via Eterea Studios) at Cocktail Party Physics. There's also a terrific list featuring some of Jennifer's favorite math books for popular audiences so go visit!

The Hive Overmind has assimilated two new blogs: Gene Expression by Razib Khan and Not Exactly Rocket Science by Ed Yong. The former focuses on the squishy science (though, like the rest of us, isn’t afraid to post strong opinions), and the latter covers science in general.

Please welcome these blogs to our collective brain!

Do you often feel the need for a sweet sugar rush or a moment of bacon-induced bliss? A new study offers evidence that that surge of pleasure is similar to a heroin high, and that eating junk food regularly can significantly change the brain’s chemical make-up, creating junk food addicts who are driven to overeat.

Lead researcher Paul Kenny says it had previously been unclear whether extreme overeating was initiated by a chemical irregularity in the brain or if the behavior itself was changing the brain’s biochemical makeup. The new research by Kenny and his colleague Paul Johnson, a graduate student, shows that both conditions are possible [Scientific American].

For the study, published online in Nature Neuroscience, Kenny and colleagues headed to the grocery store. “We basically bought all of the stuff that people really like — Ding-Dongs, cheesecake, bacon, sausage, the stuff that you enjoy, but you really shouldn’t eat too often,” he said [Reuters]. One set of lab rats was allowed unfettered access to these high-calorie foods, while another rat group was allowed just one hour of access to the junk food per day. Both sets of rats also had the option of eating standard healthy lab rat fare. Finally, a control group of rats were kept on a healthy diet.

Scientists found that rats with unlimited access to junk food quickly became addicted. They constantly munched on the junk food through the day, becoming substantially overweight and turning into compulsive overeaters. Meanwhile, the rats with limited access to the food held their hunger, preferring to binge-eat in a limited time than consume healthy rat food. These rats gorged for 60 minutes, consuming 66 percent of their daily calorific intake in just one hour and soon developed a pattern of compulsive binge eating.

The researchers found that rats that overate had altered brain chemistry. Initially, each time they ate a Ding-Dong or rasher of bacon, they got a shot of the feel-good chemical dopamine. But just like human drug addicts, they soon had to increase their dosage to get the same dopamine rush. As the pleasure centers in the brain became more and more blasé, and less responsive, the rats quickly turned into compulsive overeaters. They were motivated to keep eating to get their fix [The Vancouver Sun]. Specifically, Kenny and his colleagues found that overeating decreased levels of the dopamine 2 receptor in the rats’ brains; human drug addicts have also been showed to have reduced levels of dopamine 2 receptors.

The altered brain chemistry also seemed to make it difficult for the rats to switch away their unhealthy eating habits–in other words, they were hooked. When the rats were eventually barred from eating junk food and given only what researchers called “the salad bar option,” they took an average of 14 days before they would even consider eating healthy food. “I was really shocked at the magnitude of the effect,” Kenny says. “They basically don’t eat anything. If that translates over to us as a species, that’s a major problem” [Scientific American].

The findings in a study of animals cannot be directly applied to human obesity, but may help in understanding the condition and in developing therapies to treat it [Reuters]. But Kenny says it’s possible that some people may be born with a predisposition to have lower D2 levels. “That may be why they’re more likely to gain weight. They’re already halfway down that road, if you will” [The Vancouver Sun].

Related Content:
80beats: Cheesecake Is Like Heroin to Rats on a Junk-Food Diet
Not Exactly Rocket Science: Making Sense of Obesity Genes
Cosmic Variance: Cheap, Crappy Calories
Discoblog: Just Like Humans, Crows Embrace Junk Food… and Pay the Price

Image: Wikimedia