This map shows mountain symbols above a river symbol. Suppose that, in the part of the world that the map represents, there really are mountains in the location that the map indicates. But suppose that there are also mountains on the other side of the river — where no mountains are indicated on the map. Would we say that the map is inaccurate?

People tend to say yes — in general, if a marker appears on a map, then we tend to think that the absence of the marker reflects an absence of that feature from the corresponding location.

But this is very different from linguistic representation. “After all,” writes Rutgers philosopher Ben Bronner, “if I say that there are mountains north of the river, the accuracy of my assertion doesn’t depend on whether there are mountains south of the river.”

And suppose I drew a map on which some national capitals were indicated, but not all. We wouldn’t take this to mean that the absent capitals don’t exist, merely that the map is incomplete. So how can we make sense of the intuition?

(Ben Bronner, “Maps and Absent Symbols,” Australasian Journal of Philosophy 93:1 [2015], pp. 43-59.)

The town of Bozouls in the south of France sits at the edge of a horseshoe-shaped canyon 300 feet deep, the product of 2 million years of erosion of the region’s limestone plateau by rivers and glaciers.

Because the outcrop at the center of the horseshoe is accessible only from the south, it makes an ideally defensible position, and a castle was built there in the 9th century, of which only ruins remain. In medieval times guards in towers monitored the approach 24 hours a day.

One historic building still survives: The 12th-century St. Faustus church sits right on the edge of the cliff, looking over the river.

In 1993, Greenland issued a 7.25-krone stamp depicting a locally fished crab that it labeled Chionoecetes oiliqo. The stamps were issued first in sheet form, but when they were reissued five months later in an eight-stamp booklet pane, collectors noticed something odd: The crabs’ Latin name had changed to Chionoecetes opilio.

What had happened? It turns out that the second name is correct; apparently during production the species name opilio had been mirror-reversed by accident. By a very unlikely coincidence, in the sans-serif typeface used all of its letters reversed into valid counterparts, producing a meaningless word that looked plausibly Latin and got past the inspectors.

The original stamps are now collectors’ items.

(Jim Puder, “OILIQO, The Looking-Glass Crab,” Word Ways 36:4 [November 2003], 243-246.)

volant
adj. engaged in flight

espieglerie
n. impish or playful behaviour; mischief

apopemptic
adj. pertaining to leave-taking or departing

réclame
n. publicity or notoriety

In 1953, 61-year-old British ace Christopher Draper flew an Auster monoplane under 15 of the 18 bridges on the Thames, negotiating 50-foot arches at 90 mph.

“I did it for the publicity,” he told the press. “For 14 months I have been out of a job, and I’m broke. I wanted to prove that I am still fit, useful and worth employing. … It was my last-ever flight — I meant it as a spectacular swan song.” He was fined 10 guineas.

Suppose that your dream-life underwent a remarkable change. Suppose that on going to bed at home and falling asleep, you found yourself to all appearances waking up in a hut raised on poles at the edge of a lake. A dusky woman, whom you realize to be your wife, tells you to go out and catch some fish. The dream continues with the apparent length of an ordinary human day, replete with an appropriate and causally coherent variety of tropical incident. At last you climb up the rope ladder to your hut and fall asleep. At once you find yourself awaking at home, to the world of normal responsibilities and expectations. The next night life by the side of the tropical lake continues in a coherent and natural way from the point at which it left off. Your wife says, ‘You were very restless last night. What were you dreaming about?’ and you find yourself giving her a condensed version of your English day. And so it goes on. Injuries given in England leave scars in England, insults given at the lakeside complicate lakeside personal relations. One day in England, after a heavy lunch, you fall asleep in your armchair and dream of yourself, or find yourself, waking up in the middle of the night beside the lake. Things get too much for you at the lakeside, your wife has departed with all the cooking-pots, and you suspect that she is urging the villagers to sacrifice you to the moon. So you fall on your fish-spear and from that moment on your English slumbers are disturbed no more than in the old pre-lakeside days.

— Anthony Quinton, Thoughts and Thinkers, 1982

“Is such a two-space reality conceivable?” asks Peg Tittle in What If…: Collected Thought Experiments in Philosophy (2016). “That is, is it conceivable that we could live in two different but real spaces?”

See Figure and Ground.

Set into the corner of Seventh Avenue and Christopher Street in Manhattan’s West Village is a triangular plaque reading PROPERTY OF THE HESS ESTATE WHICH HAS NEVER BEEN DEDICATED FOR PUBLIC PURPOSES. The “Hess triangle” is a remnant from a property dispute that unfolded here 100 years ago: The city was claiming eminent domain in order to demolish hundreds of buildings and expand the subway, but surveyors overlooked this 65-centimeter triangle, owned by Philadelphia landlord David Hess. Hess, outraged at the loss of his five-story apartment building, refused to donate the triangle to the public and added the plaque as a sort of existential revenge. In 1938 it was sold to the adjacent cigar store, and today it’s owned by a local realty corporation, the smallest plot of land in New York City.

Related: In 1973, artist Gordon Matta-Clark bought 13 unused pieces of land that were left over when property lines were redrawn in the borough of Queens. He paid between $25 and $75 for each. The sites are often irregular or isolated, located where other properties meet in a block, some measuring as little as 2×3 feet.

“When I bought those properties at the New York City Auction, the description of them that always excited me the most was ‘inaccessible’,” he said. “They were a group of fifteen micro-panels of land in Queens, leftover properties from an architect’s drawing. One or two of the prize ones were a foot strip down somebody’s driveway and a square foot of sidewalk. And the others were kerbstone and gutterspace. What I basically wanted to do was to designate spaces that wouldn’t be seen and certainly not occupied. Buying them was my own take on the strangeness of existing property demarcation lines. Property is so all-pervasive. Everyone’s notion of ownership is determined by the use factor.”

(Jeffrey Kastner and Brian Wallis, Land & Environmental Art, 2005.)

In 1764 Oxfordshire squire Edward Horne decided that the parish church of St Leonard on Watlington Hill would look more impressive with a spire. So he gave it one: By cutting a narrow mark 270 feet long into the chalk soil beyond the building, he was able to perch a foreshortened triangle atop the church when it was viewed in perspective from his house. Local residents maintain the mark to this day.

“Always let your conscience be your guide,” Jiminy Cricket tells Pinocchio. And so we are constantly telling one another: We seem to believe that following our convictions, whatever they are, is better than “giving in to temptation,” regardless of the outcome. Similarly, resisting temptation and doing what I feel is morally right is somehow praiseworthy, even if it can be shown that my convictions were mistaken. We are saying:

If you believe it is wrong for you to do X then it is wrong for you to do X.

And if you do have such a conviction:

You believe it is wrong for you to do X.

Then combining these statements produces the disconcerting conclusion

It is wrong for you to do X.

This seems to mean that all my convictions about my moral conduct are correct, regardless of the facts of the matter, the substance of my convictions, and even whether I’ve considered them.

“Needless to say, this is deeply implausible,” writes University of New Mexico philosopher G.F. Schueler. “For one thing, not only do these ‘proofs’ not depend on the content of our moral convictions; they don’t depend in any way on how we arrived at these convictions. They ‘prove’ the convictions not only of the moral philosopher who has spent her life seriously reflecting on morality, but also those of the most superficial ditz, who has never read or thought about anything more profound than comic books or video games, not to mention the racist bigot who is convinced that it is wrong for her to allow blacks to vote and the religious zealot who thinks all those who don’t accept her religion should be driven out of the country. They ‘prove’ absolutely everybody’s convictions equally.” And that means we must doubt and study even our own convictions … which is much harder than relying on a cricket.

(G.F. Schueler, “Is It Possible to Follow One’s Conscience?”, American Philosophical Quarterly, 44:1 [January 2007], 51-60.)

In 1848 the French commune of Le Plessis-Piquet distinguished itself with a restaurant built in the boughs of a chestnut tree. Owner Joseph Gueusquin named it Le Grand Robinson, after the treehouse in Swiss Family Robinson.

“Word spread and people started to make the eight-mile pilgrimage from Paris,” writes Pete Nelson in Treehouses of the World. “Soon, other entrepreneurs began opening their own treehouse restaurants. At the height of its popularity, there were ten such restaurants and countless other treehouse attractions.”

The trend persisted even into the 1960s, drawing a steady stream of curious diners to Le Plessis-Piquet — in fact, in 1909 the commune officially changed its name to Le Plessis-Robinson, after Gueusquin’s pioneering idea.