Until 2006, a British ambassador leaving his post would write a valedictory despatch to be circulated among select readers in the British government. These “parting shots” tended to be appallingly frank, combining the diplomat’s real feelings about the nation he was leaving with his often wounded resentment at the indifference of his own government:

• Argentina: “All I knew of Argentines before coming here was that they were generally disliked by all other Latin Americans as unduly pretentious, snobbish upstarts. …. The per capita outlay on deodorants in the Argentine is the highest in the world.”
• Finland: “It could plausibly be argued that it is a misfortune for anybody but a Finn to spend three years in Finland, as I have just done. … Finland is flat, freezing, and far from the pulsating centres of European life.”
• Uruguay: “After living now for over two years among people who call themselves Orientals and who seem to have inherited nearly all the faults and none of the virtues of Spain (though they have many minor virtues of their own), I look forward to returning to what I conceive to be, at least by contrast, the speed and efficiency of my own country.”
• Saudi Arabia: “It is a great tragedy that, with all the world’s needs, Providence should have concentrated so much of a vital resource and so much wealth in the hands of people who need it so little and are so socially irresponsible about the use of it.”
• Thailand: “Decayed garbage left for months on the side of the roads; stagnant canals that serve both as cesspools and as the dumping ground for dead dogs; buses and lorries that belch uncontrolled clouds of diesel fumes; scarcely a pavement without potholes and open manholes to break the legs of the unwary; bag-snatchers in every block; assault and violence a way of life; prostitution and every form of natural and unnatural vice on a scale astonishing even in Asia; a city of 4 million with only one park, and that littered with refuse and infested by thieves; unplanned hideous ribbon development; no proper drainage, so that in the rainy season large areas of the city remain flooded for weeks on end; and the whole set in a flat mournful plain without even a hillock in sight for 100 miles in any direction: this is Bangkok, the vaunted Venice of the East.”

Matthew Parris, who published a whole collection of these in 2010, explains: “Beyond retirement there can be no reprisals.”

Suppose a local bar has 100 regular patrons. The bar is rather small, and going there is enjoyable on a given night only if fewer than 60 people show up. This is a problem: I want to go to the bar, but I expect to enjoy it only if you don’t come. But I know that you’re thinking the same thing about me. If no one communicates in advance, how many people will tend to turn up at the bar?

In a 1994 computer experiment, Stanford University economist W. Brian Arthur assigned each patron a set of plausible predictive rules on which it might base its decision. One rule might predict that next week’s attendance will be the same as last week’s, while another might take a rounded average of the last four weeks, and so on. Then, in practice, each patron would downgrade its badly performing rules and promote the more successful ones, and revise these ratings continually.

What he found is that the mean attendance converges to about 60, forming an “emergent ecology” that Arthur said is “almost organic in nature.” The population of active predictors splits into a 60/40 ratio, even though it keeps changing in membership forever. “To get some understanding of how this happens, suppose that 70 percent of their predictors forecasted above 60 for a longish time. Then on average only 30 people would show up; but this would validate predictors that forecasted close to 30 and invalidate the above-60 predictors, restoring the ‘ecological’ balance among predictions, so to speak.”

This is heartening to see, because life is full of such murky decisions. “There is no deductively rational solution — no ‘correct’ expectational model,” Arthur writes. “From the agents’ viewpoint, the problem is ill-defined, and they are propelled into a world of induction.”

(W. Brian Arthur, “Inductive Reasoning and Bounded Rationality,” American Economic Review 84:2 [May 1994], 406-411.)

Most people would agree that children have special duties to their parents, even once the children have grown up. We might feel an obligation to keep in touch with them, for example, or to care for them in their old age. Where do these duties come from?

• Certainly my parents have done a great deal for me, so perhaps I owe them a debt. But it seems there’s no way to repay this debt completely, and I seem to owe it regardless of how great (or small) a burden I was to them as a child. (Also my obligation to them seems to vary with my own circumstances, which is not the case with other debts.)
• Perhaps what I really owe them is an appropriate gratitude for what they’ve done for me. But this doesn’t seem right either — if I help my mother through a difficult time, fundamentally it’s because she wants me there, not to show that I recognize and appreciate what she’s done for me. Also, I seem to feel a duty to her even if I required relatively little sacrifice as a child, which is not normally how we think about gratitude.
• Maybe my parents and I are friends, and I owe them the duties that come with friendship. But I can’t choose to end our relationship, as I can with friends, and I would never feel an obligation to provide medical care (say) for my friends, as I would for my parents.

Each of these explanations is unsatisfactory, writes Boston University philosopher Simon Keller. “Each tries to assimilate the moral relationship between parent and child to some independently understood conception of duty, but this relationship is different in structure and content from any that we are likely to share with anyone apart from a parent.” So what’s the source of our obligation to our parents?

(Simon Keller, “Four Theories of Filial Duty,” Philosophical Quarterly 56:223 [April 2006], 254-274.)