The natural virtues are the central cases of virtue and vice for Hume. The artificial virtues, such as justice, present problems for Hume’s theory of the virtues. Our tendency to think that justice is virtuous and injustice is vicious requires a different kind of explanation than the one given for our thoughts about the natural virtues and that is what Part 2 of Book 3 provides.
Natural virtues are directly good: they are agreeable or useful. But the artificial virtues are sometimes not good at all, or, at least, not good on their own. Justice requires paying nasty, unpleasant, wealthy people (which is not to say that those qualities always go together) even at the expense of nice, lovable, poor ones who could make far better use of the money (18.104.22.168).
Since this is so, why do we approve of justice? That’s the question.
The answer comes in two parts.
First, why do we have rules of justice in the first place? This is puzzling given some facts about human motivation. The answer is that the rules of justice arise out of self-interested conventions: agreements that work to the benefit of all participating parties. “I’ll row the boat if you will do the same” is such an agreement. We get the rules of justice from mutually beneficial conventions such as these.
Second, why do we approve of just behavior (and disapprove of unjust behavior)? We appreciate how important having rules of justice is and we sympathize with the public interest. Those who comply with the rules benefit the public interest and those who break them harm it.
Did he really explain it?
Paul pointed out that Hume did not really explain what he set out to explain: why we are motivated to comply with the rules of justice, such as those that define property rights. His story is that we are motivated to keep these rules by self-interest and we approve of the behavior of keeping the rules by our sympathy with the public interest (with the latter having some effect on our motivation to comply as well).
But that’s not really going to do the trick. As Hume himself pointed out, self-interested motivation will not get me to comply with the rules of justice. Rather, it will get me to comply insofar as I fear the consequences of being caught. Sympathy with the public interest has a similar problem, as I can break the law without bringing down society, and it has limited motivational power in any event.
What Hume needs, it seems to me, is a more complicated psychological theory. He needs to explain how we can internalize moral rules, such as the rules of justice, where that means accepting and acting on them without thinking about how they are related to self-interest or the public interest. It seems evident to me that we can identify with rules, in this sense, and that Hume could say something along the lines of “the rules were created by self-interested people, but human psychology is such that we internalize the rules that we grow up with and comply with them without thinking about whether doing so best realizes our own interests or not.”
Is Hume a consequentialist?
Max has posed this question on several occasions. A consequentialist is someone who believes that the morally required act is the one that brings about the best consequences overall.
Hume is not a consequentialist, so defined, for two reasons. First, his theory is not about what acts are right or wrong but, instead, it is about why we think that some things are right and others are wrong. Second, he correctly notes that we are not consequentialists. We think that justice can require forcing the poor person to pay the miser, even though that has worse consequences than letting the poor person keep the money.
(There’s a potential complication here. Does he think that we do this only because we think that breaking the rules of justice would cause harm to society that would be worse than the harm done by giving the money to the miser? It isn’t clear what he thought about this point. I think he held that our approval of just behavior is caused by the relationship between the rules and the public interest as a general matter, not by a thought that any particular act would be harmful. But I’m not sure about that.)
Nor is Hume a consequentialist in a weaker sense, namely, that people are good (bad) only insofar as their behavior has good (bad) consequences. Remember virtue in rags. His only point is that we identify virtues by their typical good effects. He does not insist that the value of our behavior or our character is measured only by the value of their effects.
Some insufficiently appreciated arguments
I think that the points about the sharpness of the rights and duties of justice compared with the gradations among natural virtues (3.2.6) are quite clever and generally underrated.
They don’t fit very nicely into the other points that we were talking about, so I didn’t want to give the impression that they were worth ignoring. So I wrote this.