I mentioned the old "dismal science" slight on economics the other day. It's not exactly new news, but I like the story of the origins of the term a lot, because knowing it would surely cause people to think twice before using the phrase.
Here's a good article that tells the story of Thomas Carlyle's first uses of the phrase.
"Carlyle attacked Mill, not for supporting Malthus's predictions about the dire consequences of population growth, but for supporting the emancipation of slaves. It was this fact—that economics assumed that people were basically all the same, and thus all entitled to liberty—that led Carlyle to label economics "the dismal science.""
Now, economics is probably pretty low on the list of reasons to oppose slavery, but it seems that Carlyle was taking issue with John Stuart Mill (among others) for arguing that since people are basically the same, there's no such thing as a "natural" hierarchy of people. Carlyle's position, sadly, speaks for itself:
"Carlyle disagreed with the conclusion that slavery was wrong because he disagreed with the assumption that under the skin, people are all the same. He argued that blacks were subhumans ("two-legged cattle"), who needed the tutelage of whites wielding the "beneficent whip" if they were to contribute to the good of society."
Aside from its connotations - which are about as politically incorrect as it's possible to be these days, and would certainly not be allowed to be printed in any of the places where we see the phrase "dismal science" - the target Carlyle was directing his argument towards is not much like the method of economic science at all. In fact, he seems to really be taking issue not with the practice of scientific, positive economics but with the assumptions the economists made about people. From another article on the same subject:
"In short, Carlyle was of the view that compulsion, rather than market forces should regulate the supply of labour on plantations in the West Indies because the laws of supply and demand are not appropriately applied to the relationship between White and Black as they are contrary to "their mutual duties" (white = master and black = servant) as ordained by "the Maker of them both". In Carlyle's opinion: "declaring that Negro and White are unrelated, loose from one another, on a footing of perfect equality, and subject to no law but that of supply and demand according to the Dismal Science", "is clearly no solution" to the problem."
Oddly enough, and though it's probably ridiculous to compare them, Carlyle is attacking exactly the same assumption that is still criticized today: the assumption on the motivation of people in economic models. Certainly the reasoning of the critic of today is significantly less outrageous than Carlyle's, but they're shooting at the same target.
Carlyle certainly seems to demand a different kind of response than today's defense of the modeling of people - "it's just an abstraction, we know we're not being realistic". Luckily, as some of Mill's angry and eloquent responses indicate, Carlyle's normative beliefs were vigorously challenged right from the start. His assumption was, I hope we can agree, unrealistic. If he had performed a positive economic analysis based on his assumption, it would have been badly wrong and inaccurate.
No normative belief or opinion can ever be "wrong", but an assumption can certainly be wrong. Which assumption would lead to better economic science: Carlyle's assumption of natural servitude or Mill's assumption of natural equality? If Carlyle had argued that slavery was a good thing, plenty of people would have disagreed with his opinion. When he argued that people are inequal and thus servitude is a better use of people than freedom, he didn't just have an objectionable opinion, he had bad science.
Modern economics has fought hard to work the number of abstractions made on the motivation of people down to just one: rationality. We don't restrict what people care about, we just require there to be some method to the madness. Economics should be value-free, boring, scientific, clinical, and, yes, dismal, but I'd think twice before I called it the "dismal science".