I wrote about the same topic three years ago and probably at many other places, too. However, Sean Carroll revived the topic again,
Carroll says that scientifically meaningful propositions are questions about the past, the present, the future, or the eternal laws that
- might in principle be both false and true
- admit a method, at least in principle, to evaluate their truth values.
He also gives you examples of propositions that don't belong to science because one of the disqualifying conditions below holds:
- they're purely mathematical in character so they require no empirical input at all
- they're statements about fictional objects such as Hamlet that can't be decided from the only available data, in this case the text of Hamlet (there's no "real Hamlet" offering "additional data")
- they depend on subjective opinions and preferences
I completely agree with all these propositions. It may be useful to discuss some additional opposition. Many people who tend to say that morality may be derived scientifically are inclined to define morality as something positively correlated with the principle
We should work to maximize the well-being of conscious creatures.Well, not everyone agrees with this thesis – count me as an agnostic here – but even those who do agree can't transform this assumption into science because pretty much by construction, this thesis (about the rightness of improvements of the well-being) is as vague and subjective as the original one (about morality in general).
How do you quantify the well-being of conscious creatures? The first problem is that even the "conscious creature" isn't really well-defined. This point is ultimately nearly equivalent to the deep moral disagreement of people of different religions or ideologies. I am referring to women's rights, animal rights, savages' rights, infidels' rights, poor people's special rights, homosexual rights, humanrightism in general, and so on. Different ideologies inevitably differ in the weight they attribute to different subjects' right to contribute to the "body of conscious creatures" and in the evaluation of their right to enjoy "well-being in their characteristic way".
Second, even if you knew who is a conscious creature and how important this creature should be in the definition of morality, it's still true that their well-being is not measured in meters, seconds, kilograms, joules, kelvins, electronvolts, candelas, and not even in dollars. Some people may decide that well-being is very close to some of those – the more sensible people could express it in dollars but the really unhinged ones may use an arbitrarily crazy unit, e.g. one negative gigaton of carbon dioxide, to measure the well-being of conscious creatures.
In science, we often lack the "best definition" of a concept – for example, we still feel that there might be some universal equations of string/M-theory – and it's therefore sensible to expect that certain things will become not only scientific but rigorously defined, high-precision concepts in the future.
However, pretty much by its basic character, this is not the case of morality. Imagine that you find some quantity M encoded in the equations of M(orality)-theory in the future and you will claim that it measures morality. It may be given by a pretty formula. I don't know whether it would be a local or global quantity – none of the options makes too much sense – but there will be a nice formula.
The problem is that even with this nice and well-defined formula, one may always legitimately refuse such a measure of morality and choose a completely different one. We may consider M as the measure of morality to be misguided for particular reasons. We may even consider the very idea of converting morality into a mathematical expression to be deeply immoral. At most, M would be another competitor of the Bible and Quran and Marx's books.
We may look what's wrong with various attempts to quantify the well-being. For example, Hugo Chavez died and some people – including some politicians who are supposed to represent the people of Europe but they behave shamefully instead – have argued that Chavez has been a great politician who has improved the well-being of the people of Venezuela. Now, I must say: give me a break with this communist garbage!
Venezuela has lots of fossil fuels and a great potential but what we see is an oppressed country with B-class ratings, unexplainable debt that is already at 50% of the GDP. They're 177th in the "easy of doing business rank" which is next to catastrophic. Lots of people remain unemployed, lots of people are below the poverty line. Relatively to other excessively oil-rich nations, Venezuela's GDP per capita is low.
The White Town's 1997 song, Your Woman [I could never be your woman], has made it to Lumo's all-time 100 hits. Because it's a song by a straight girl in love with a lying, two-timing, fake-ass Marxist who has manipulated her, I dedicate it to Hugo Chavez – the girl is a metaphor for the Venezuelan nation – and wish him a smooth and uninterrupted trip to Hell in whose existence I temporarily believe just for this special occasion.
Chavez's posthumous children may refer to some special indices created by the United Nations. That's great but these indices are artificial pieces of propaganda composed by Marxists and by the terrorist friends of Chavez, Ahmadinejad, and their Western politically correct apologists – all these bastards de facto "own" the United Nations. There's nothing credible about those things. They're deeply immoral.
Many of these indices – attempts to quantify the well-being of conscious creatures – incorporate egalitarianism as a positive condition. The smaller the wealth inequality is, the better, these commies want to argue. Give me a break with this junk. There is nothing nice or ethical about egalitarianism and there is nothing wrong about wealth inequality. Wealth inequality – the concentration of capital – has been both an inevitable and by definition fair and just consequence of people's varying contributions to others (plus some fluctuations that are explained by less noble causes but there's no reason for the total inequality to equal zero); as well as a necessary precondition for the progress of the human society.
People who back egalitarianism are downgrading the humans into cattle of a sort, cattle that is measured either in kilograms or pieces. Mass brainwashing and indoctrination of the citizenry becomes pretty much another "must" for everyone who wants to create an egalitarian society. When people are treated in this way, they obviously become less conscious, less thinking. People actively supporting egalitarianism are inhuman hyenas who should be tried for crimes against humanity and perhaps executed if the well-being of the conscious creatures is our goal. Now, I can't give you a scientific proof – neither a rigorous mathematical proof nor a rock-solid piece of scientific evidence – that the previous sentence is true. What I say is still true although it's true in a different sense than scientific propositions.
Some people who suggest that moral questions may be settled by science are usually narrow-minded folks who agree with a couple of their friends – or a mass movement of a sort – and because these friends or movements also tend to pay a lip service to science, they identify science with the morality. But even if their support for science went beyond the lip service, it would still be incorrect to identify science and a particular kind of morality just because both are supported by the same group(s) of people!
At the end, it seems to me that the people promoting a "scientifically established morality for everyone" haven't even tried to think about the immense diversity of viewpoints, values, and priorities that make the moral opinions of the mankind across the space and time so non-uniform. Let me give you an example.
Last night, our Pilsner soccer team, Victoria, was beaten 1-to-0 by the visiting Fenerbahce Instanbul, a very rich team supported by 1/3 of the Turks worldwide. It was a sort of surprise for our celebrated team but the Turks were playing better than us – and therefore much better (and in a more organized way) than teams such as Napoli. But that's not what I want to talk about. ;-) Twenty minutes ago, I bought and ate a kebab box in my favorite nearby kebab shop. They raised the prices today, bastards! But the prices are also not the topic here.
What I want to say is that these Muslim nations are slaughtering animals in the halal way – it's their version of the Jewish kosher way. They find blood to be unacceptable in food and the execution of the animals corresponds to these principles. The Egyptian guy has warned me about that many times. I checked – and yes, the halal slaughtering involves cutting the animal near the throat and discharging pretty much all the blood from the body.
It looks cruel, I want to cry, vomit, or whatever, but I was nearly killed 16 years ago in almost the same way (and it was my birthday) so it's no real science-fiction (some seven stitches or so did the job). Moreover, the European ways to slaughter animals seem terribly cruel to me, too. And at the end, even if you make an animal (or human) sleep so that it doesn't realize that it dies when it does, I still find it horrible. Differently horrible, creepy, but still horrible.
If you believe that some of these methods are particularly moral or immoral, you may feel extremely strongly about it but as long as you stay rational, you must realize that your feelings (and even the "right" suggestive analogies between things) are emotional, formed by your education, background, experience, perhaps genes of your family and nation, and it's completely possible that someone feels differently or very differently. These preferences are like the preferences for the best ice cream. I am surely not saying that all viewpoints are equally good; of course that only mine are any good. I am just saying that the validity of a moral system can't be proved in the same way as statements about hard sciences.
I want to mention one more alternative albeit related definition of immorality to compete with the well-being:
A habit, tradition, behavior, or even opinion that threatens the very fabric of the society is immoral.Again, one could get many people subscribe to this thesis. It's perhaps more conservative than the morality based on the well-being (the latter smells of a progressive bias – it is not shocking that it was picked by Sean Carroll) but it's not too different. The problem is that the "fabric of the society" is inevitably so much ill-defined that there can't ever be a rigorous "scientific verdict" about morality based on this criterion, either. Moreover, whether or not the society will be undermined by a particular behavior is not only "unpredictable deterministically" but it is really unknown in advance. Even if the "fabric of the society" and its preservation were rigorously defined, which is too much to ask in the real world, we could at most calculate the probability that this fabric will be destroyed because of a particular behavior.
This probability would be a number between 0 and 1. Which threshold would be tolerable? There's clearly no objective, unique, canonical answer. Moreover, the calculated probability depends on many other assumptions.
An example. During the life of Giordano Bruno, many powerful Catholics believed – unfortunately for Bruno – that heliocentrism was undermining the very fabric of the society. If people started to believe heliocentrism, something terrible would happen. What would the Armageddon be? Perhaps, the inertia from the floating Earth would throw us to outer space. Well, that's not really possible because the Sun's gravitational force acts equally on the Earth and the objects on it which is why the centrifugal and centripetal (gravitational from the Sun) forces pretty much cancel, up to tides, but yes, the understandable misunderstanding of this point (those people lived before Isaac Newton and his laws) was a reason why many people couldn't internalize the physics of heliocentrism.
But of course, the actual worries were different. It was believed (although some people had to promote this belief first: this anti-heliocentric hysteria wasn't dominant during Copernicus' life) that the Bible stated that the Earth had to be the center of everything and it was a key proposition. So any violation of this wisdom would undermine God, the body of His or Her believers, and their faith. They would quickly begin to sleep with their siblings, eat each other, Mr or Mrs God could get pis*ed off very quickly and very severely, and roughly speaking, the mankind would go extinct very rapidly.
This was the ideology behind the belief that heliocentrism was immoral and Giordano Bruno had to be burned at stake. Well, this worry hasn't materialized. The mankind no longer believes geocentrism much. Even the Catholic Church has largely abandoned it. But the mankind still exists. Even the Catholic Church is still around. It still has a Pope – well, not right now, but maybe it will have one next week.
So some belief about the "collapse of the human society" because of something turned out to be immaterial. There are lots of wrong beliefs – wrong because not sufficiently scientifically backed – underlying many or all ideologies that claim to determine what is moral and what is immoral. This is the easy part of the problem. I think that everyone understands that the worries turned out to be misplaced which means that this particular reason to promote execution of Giordano Bruno for heresy was bogus. The society and even the Church may work independently of beliefs in geocentrism or heliocentrism.
But I also want to emphasize a different point, one that is easily overlooked with the hindsight. And the point is that the moral arguments of the Catholic prosecutors had a logic and they could be right. The coupling between the fate of geocentrism and the fate of the mostly cultural Western society was weak but it was nonzero. The probability that the loss of the Church's authority would turn the Western nations into hordes of savages was arguably nonzero. More importantly, there are other situations in which the coupling is perhaps stronger and similar worries turn out to be justified.
In some cases, the society adjusts to some "potentially crippling" changes. In other cases, the changes may be so crippling and unadjustable that the society gets crippled, indeed. When the society gets adjusted, it's a slightly different society – we could say it is a mutated society – afterwords. For such a mutated society, someone who claims to quantify or "scientize" morality has to adjust all the rules, too. This quickly becomes an unsolvable problem where everything is coupled to nearly everything, all the coupling constants are unknown, their effects' morality is undefined, and it's just a mess.
One method to appreciate how unscientific all propositions about morality are is to try to apply your moral rules to some very distant societies – ideally societies that are separated by thousands of years (or more) from ours. If you're the best morality expert in the world of 2013, how will you teach the Neanderthals to be ethical? What about the future people who live in the Idiocracy of the 26th century? Clearly, the folks in both distant worlds live completely different lives and have different interests, concerns, and priorities. Even the notion of murder may get a totally different flavor due to different needs, different technologies to kill, and so on.
Your moral rules will largely mean nothing to them. Even if you strongly believe in your moral rules, you shouldn't overlook that they're provincial rules that are largely inapplicable to general enough situations – situations in which the people are too far spatially, temporally, or culturally. And that's an attribute of something that is decidedly unscientific because the scientific laws should be pretty much constant in time. Otherwise they're not really laws. The laws of moralities are inevitably descriptions of a subset of people's subjective opinions that are relevant and believed to be valid in a limited region of spacetime and the society and that may only be demonstrated to be "clearly better" than competing systems of morality if the two systems sort of fairly compete and show where their beliefs go.
However, even if you could make the competition fair, you will still have trouble with this criterion because a society may thrive due to good luck or some (genetic and other) prerequisites that are independent of the moral system so no victorious outcome is a clear proof of moral propositions, either. Moreover, you cannot step into the same river twice. Important enough "moral experiments" are unrepeatable (because the society or at least its knowledge is changing) and fail to obey the scientific requirements of reproducibility.
So I surely think that science will never become adequate to settle moral questions in practice – except for totalitarian societies where all the people are forced to believe certain things and nothing else – but I also think that moral questions are outside science even in principle.