An ideal that cannot be implemented is futile. The question is, how much of a drag on moral ideals should be exercised by the stubborn facts of human psychology? How far can moral ideals ask us to transcend our self-centered human dispositions without becoming unrealistically utopian? As Appiah says,
Some aspects of human nature have to be taken as given in normative theorizing..., but to take us exactly as we are would involve giving up ideals altogether. So when should we ignore, and when insist on, human nature?
I would suggest that to idealize in this context is not to ignore human nature but to regard it, rightly or wrongly, as capable of change. Only if the change is impossible or undesirable is the idealization utopian.
Appiah illustrates a different kind of reason to avoid excessive idealization with the example of immigration policy. To even pose the problem that faces us we have to take the existence of national boundaries as given, as well as the fact that some states treat their own citizens with flagrant injustice or are beset by chaos and severe deprivation. In thinking about what obligations such a situation places on stable and prosperous states, it is no use imagining a unified world without state boundaries, or a world of uniformly just states in which people are free to move from one to another. Such ideal possibilities do not tell us what we should do now, as things are.
Appiah's response relies on the idea of fortunate nations each doing their fair share toward alleviating the plight of those seeking asylum, while acknowledging that many nations probably won't meet this standard. This too is an ideal, but it doesn't depend on imagining a world very different from the actual one.
This immediately made me think of Bryan Caplan's push for open borders. Is that being too idealistic?
In my view, the article misses several important considerations:
1. Consider the problem of migration within China. Today, rural Chinese citizens are not free to migrate to the big cities. In one sense it would be futile for me to advocate free migration within China. My goal would be unrealistic, unlikely to succeed in 2018. And yet I don't regard this sort of advocacy as futile, as free migration within China is very likely to be achieved at some point in the future. So we need to think in terms of the time dimension, a policy that is unrealistic today may become realistic at some point in the future. In 1700, the anti-slavery movement looked hopelessly utopian. I recall a time when advocacy of gay marriage was viewed as being just as "futile" as is advocacy of open borders today.
2. Of course open borders at a global scale is a much more difficult objective than within China. But is such advocacy futile? Let's suppose that open borders would boost global welfare, but at the cost of reducing welfare for people already living in advanced countries. Does that make the goal impossible? Perhaps, but doesn't the same argument apply to foreign aid? Bill Gates donates billions of dollars to people in poor countries. The US government has a foreign aid program. These programs may boost global welfare while reducing domestic welfare. These actions would be difficult to explain in a model where people are not at least slightly altruistic. And yet foreign aid somehow exists. (And even if foreign aid is motivated by foreign policy considerations, not altruism, the same argument might apply to open borders, which would make America more populous and hence more powerful.)
3. Even if Bryan does not achieve his goal of open borders, the passionate advocacy of this policy might lead to partial victories, such as an increase in the level of immigration.
4. It is very difficult to predict which policies are realistic and which are impossible to achieve. Take the example of the 2016 presidential election. Imagine polling political scientists in 2015 on the following question:
How likely is that that a candidate with strong support in the extreme fringes of the alt-right would be elected president in 2016, despite the fact that 4 of the past 5 presidential candidates in his own party refused to endorse him?
I'd guess that most experts would have said the chances were near zero. Politics is full of unexpected surprises.
Critics of utilitarianism often point to the fact that its adherents (including me) almost never live up to the ideals of this highly egalitarian value system. And that's true. But that doesn't mean that it's futile to clearly stake out the issues, and try to show what's optimal. It's understood that people are imperfect, and will often favor their own utility over the welfare of strangers. Nonetheless, we need to be clear about what's best, even if it's is not currently achievable. We need a goal to aim at; while we decide how much sacrifice we are willing to make for the overall well being of society.
I would not expect Americans, or the Japanese, or the Swiss to immediately opt for open borders, even if that regime were optimal. But I would try to educate all three groups as to the advantages of immigration. I'd also hope and expect that they adopt an immigration policy that allows considerably more immigration than would be allowed under a regime that takes no account of the welfare of foreigners. Recall that Americans turned away Jewish refugees during the early 1940s. Is it possible that Americans might have done somewhat better if they had been fully informed of the issues at stake?
There is no reason to treat "ideals" and "human nature" as two alternative choices. We can recognize that both are important. We need to try to figure out and clearly describe the ideal policy regime, and then use that as a lodestar to aim at with the full understanding that human nature will never allow us to get 100% of the way to an ideal society.
The same argument applies to non-utilitarian value systems, such "natural rights libertarianism". If you believe in that system, it's worth fighting for even if you can never achieve 100% success.
We also need to understand the different roles played by different people in society. The democratic system helps to prevent policy from getting too far out ahead of the public. The immediate implementation of Bryan's open borders proposal might lead to a backlash against immigration, whereas this sort of backlash is less likely from a more cautious proposal that advances through both houses and is signed by the President. The role of intellectuals is (and should be) very different from the role of policymakers. Broad policy goals (not details) should reflect the wisdom of voters, even if the average voter is not very smart. Intellectuals should try to shape public opinion (although they will always be less influential than filmmakers.)