Hume famously said that reason is and ought to be the slave of the passions. Humeans are moral non-cognitivists (emotivists, in particular), and believe moral judgements are, ultimately, just sentiments. "Inequality is bad" or "Agression is bad" wouldn't mean anything, but would just express attitudes (Boo inequality!, Ugh violence!).

There are some Humeans in the net among people I read. Here they are:

Our first Humean is Chris Dillow, who writes

Nor is it obvious that the emotions which give rise to taboos can be subjected to the tribunal of reason. David Hume, for one, thought not:

Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them... Where a passion is neither founded on false suppositions, nor chuses means insufficient for the end, the understanding can neither justify nor condemn it.

I'll confess that this is true for me; my antipathy to inequality is, at root, an emotional one and my apparently rational arguments are the slave of that passion. I suspect - though cannot prove - that the same is true of Dawkins. Reading The God Delusion gives me the impression that Dawkins is motivated by an emotion of disgust at some of the effects of religion. I happen to share that feeling in many ways, but it is a feeling. (Limits of Rationalism, 2014)

Between those two posts, I've given a dozen good reasons for left-libertarianism. But reason is only the slave of the passions. Here are the real causes of my left libertarianism. 1. I've got a problem with authority. One of my earliest memories is of my dad being arrested; my earlier memories are of his violent temper. For me, power and authority are fists, not helping hands. 2. I've worked in financial markets. I've therefore learned that Hayek was right. Individuals can't know more than the market, on average. 3. I'm a loner. This has two effects. First, it gives me a preference for liberty -  leave me alone - over community. Second, it means my political beliefs have not been shaped much by the opinion of other people. Instead, they come more from the literature. And the good literature is more liberal and less managerialist than popular opinion. 4. I've never properly fitted in with the rich. Be it grammar school, Oxford, the City or just a posh part of London, I've never felt truly at home. The interests and attitudes of the upper-middle class have never been my interests or attitudes. 5. I'm risk averse, with cheap tastes. My instinct, then, is that the state should provide a safety net, and not worry too much about letting the rich keep their millions. **Rationality, then, isn't the cause of my political beliefs. And I doubt it's the cause of anyone else's.  **(Why I'm a left libertarian, 2006)

Our second Humean is Noah Smith,

Of course, as I said at the beginning of this rant, this is not really how I like to think about ethics. I'm an Aristotelian rather than a Platonist when it comes to right and wrong; I see ethical systems more as attempts to order and classify a fundamentally jumbled empirical reality, rather than pure ideas from which real people's morals emerge. And as I see it, the is-ought rule means that internally self-consistent ethical systems are no intrinsically better than self-contradictory ones, so the whole exercise of trying to corral people's beliefs into a periodic table yields little practical benefit. My own ethical system is sometimes libertarian, sometimes utilitarian, sometimes both, and sometimes neither; and_I'm fine with that_.  (All ethical systems are both deontological and consequentialist, 2011)

Now you might ask: "Noah, why do you think there ought to be such an activity?" Well, I could just reply that it's purely my moral intuition, and as a Humean, I don't need any other justification. In fact, any justification I give will open itself up to questions of "But why?", until I finally just say "Because that's just how I feel", or "Oh come ON!". [...] Now, I don't think this norm is universal and overriding.I'm a Humean, not a deontologist - I have no need to establish _a priori_moral axioms that encompass all situations. I can think of extreme situations where I'd violate this norm. If the Nazis tell you to build a nuke, go ahead and sabotage that project! ( Science vs. politics, 2015)

There is actually a mildly intellectually interesting philosophical question here, which is: "Is there a finite set of ethical principles that will yield a set of rules of capitalism whose cardinality is larger than the cardinality of the set of ethical principles?" I suspect there is, but I also don't care, because I am a Humean, and I reject all clearly delineated ethical rules in favor of fuzzily defined, intuitive principles. (Arbitrary value systems are arbitrary, 2014)

**This post really made me want to vomit. It is morally repugnant and disgusting in the extreme.** It deserves strong condemnation, and possibly a hurled water balloon filled with the unsavory excretions of an African hyena. It is _the_ most sickening thing I have read in the econ blogosphere, bar none.
But as economists, we are supposed to be dispassionate. We are supposed to overcome our biases and dwell in a realm of pure reason. And so I will rebut Landsburg's post not based **on its severe moral failings**, but on its logical shortcomings, of which there are many. For the post is not merely offensive, it is poorly thought out. ([In which Steve Landsburg makes me lose my lunch](, 2012) [Note here, Explicit emotion based moral judgement, in line with Hume]
I think of myself as a pragmatist. I don't have a very self-consistent, well-defined ideology to myself. I can't really--**I think of myself as a Humean [David Hume]. I have these _moral instincts_**--I think, 'Oh, well, you know, this is too much a restriction on individual liberty' and 'I don't like _that_.' And then in some other case I'll think, 'Oh, look at these poor people,' you know, 'We've got to have the government do something to help those poor people.' **And there's not necessarily a rhyme or reason to that. It's just sometimes I have one instinct and sometimes I have the other. And I think of those moral instincts as sort of the primitive, primal, basic elements of morality, and they don't always work--they don't always form a self-consistent whole.** Now, you know, when I look at what really works for nations, what I think looks good for nations, you know I think the rich countries of the world are all doing pretty well: the United States is a great place to live; Canada, Japan, France, Germany, Singapore--I don't really know as much about Singapore. But these are all _really_ good places to live. Every place I have seen is good. And there are some small taste differences. I mean, life in France is not going to be quite like life in Japan. But they are all doing pretty dang good. And, you know, I mean, _maybe_ a radical overhaul where we _dramatically_ decrease the size of government would be even better. And maybe some country will try that. You know, I'm for experimentation; maybe someone will try that. But so far all the countries we see with these great qualities of life, these very successful countries, all have big government _in_ them. And to me, that says that we should at least be pretty cautious before we toss out big government completely. ([EconTalk](, 2015)
More to be added.