Letters

I was surprised by the tone of Stephen Mulhall’s letter in response to my essay on conjoined twins, and to be told that I had demonstrated ignorance of the philosophical debates on applied ethics, personal identity and the mind-body problem (Letters, 19 August). Fourteen lawyers were in court for the Gracie and Rosie Attard case in September 2000; all recognised they were engaged in a philosophical as well as a legal debate. Lord Justice Walker’s judgment included a list of academic authorities on the ethics of euthanasia. A section of Lord Justice Brooke’s judgment was headed ‘Necessity: modern academic writers’. But these authors were of limited help because the choice the court faced was different in character from the situations they had discussed. I gather, however, that the philosophical literature has moved on since 2000, particularly with the publication of Jeff McMahan’s The Ethics of Killing, reviewed by Mulhall in the LRB (LRB, 22 August 2002).

As for personal identity, there are plenty of philosophical discussions of ‘brain-division, brain transplantation, bodily fusion and so on’, but none, I think, of conjoined twins. Finally, I said nothing about the mind-body problem. I did say that the position of Gracie and Rosie was comparable to that of passengers in an overcrowded lifeboat, in that one could survive only at the expense of the other, yet both had a right to be in the boat. Arguments about this sort of situation go back to Cicero. Mulhall moves from my word ‘belongs’ to his word ‘possession’, and, via a pun, to ‘possessed or haunted’, conjuring up a Cartesian ‘ghost in this physiological machine’. So he convicts me of holding a sub-Cartesian position on the mind-body problem when I said nothing at all about the relationship between minds and bodies: what I discussed was the situation of two people who were completely dependent on a resource (oxygenated blood) of which the supply was insufficient, and what I argued was that the blood couldn’t properly be said to ‘belong’ to just one of them. Mulhall claims that my ignorance ‘nourishes fantasy’, but here at least he is arguing with a fantasy figure, not with me.

In his review of James Surowiecki's The Wisdom of Crowds (LRB, 5 August), David Runciman misses an important point about the use of experts. The obvious requirements for choice of sample, independence and so on are only necessary conditions, not sufficient ones. A properly random sample of people can be completely wrong about something if they are all working on the same incorrect assumption. Consider the jellybean example: if there is a large glass sphere hidden among the jellybeans, then you will get a normal distribution of guesses centred on the wrong mean. An expert – someone who knows about the glass sphere – will be able to make a much more accurate guess.

If you want to determine the relative usefulness of experts and crowds in a particular situation, you need to consider the relationship between them, and the ability of the crowd to make reasonable guesses. There are situations in which there are no real experts, such as an unfixed jellybean contest; situations in which everyone is an expert; and situations in which there are real experts. A good example of the second type of scenario is betting on horses. Ask a thousand random people to look at the form and then bet on a race and most professional gamblers will be happy to bet according to the crowd's decision.

A simple example of the third type of situation is the well-known doubling problem: ask a thousand randomly chosen people how much money you'll have in a month's time if someone gives you a penny today, two tomorrow and so on. The group mean will almost certainly be an answer that's much too low; but ask an expert (anyone who understands basic exponential functions) and you'll get the right answer. The run-up to the war in Iraq was probably one of these situations. The point as regards Iraq is not that the crowd somehow knew better than the experts, but that the experts lied.

It is a fundamental principle of experiment that, if there’s no bias, experimental error will be randomly distributed. That’s why an experimenter will repeat his experiment, and average the results. The average, with experimental error roughly cancelled out, will be more accurate than a single measurement. It should be no surprise that this applies to guessing the number of jellybeans in a jar. If, however, we asked people to guess the number of jellybeans in a jar labelled ‘1000 jellybeans’, the average guess would be in the neighbourhood of 1000. The label introduces a bias into the experiment.

Runciman proposes that matters of public policy be submitted to ‘a large group of people … to give it their best guess’. But while we can easily find unbiased jellybean counters, I would not know where to look for unbiased policy-makers. Had such a process been applied to the decision to invade Iraq last year, the American people would have approved it (Runciman is wrong to suggest the opposite). Public opinion last year was biased (in the experimental sense) by the overwhelmingly one-sided propaganda favouring invasion. We see through this now, but all the averaging in the world could not have saved us then.

‘Taken individually,’ Rachmaninov once said, ‘the people in an audience may be poor critics of music, but as a complete body, the audience never errs.’

I was pleased to see that Campbell Lennie set the record straight about Orson Welles being buried in Ronda, rather than Seville (Letters, 8 July). Perhaps more than his affection for his friend Antonio Ordóñez the reason he asked to be interred there was his love of la fiesta brava – Ronda is generally acknowledged to be the cradle of the corrida.

In 1962 I had a marvellous mano a mano lunch with Orson at his Malaga villa; he wanted to talk about bulls (of which he knew a great deal) and I wanted to talk about his films. Later that day we went to the corrida with Kathleen and Ken Tynan. The third bull charged into the plaza and leapt over the barrera with its hooves virtually in Orson's lap. We pushed it back into the callejón, where it killed the carpenter of the ring. What a day!

Frank Kermode says that ‘narratology’ isn’t in the OED (LRB, 5 August). it’s in the online version, with a first citation from Todorov, 1971.

Andrew O'Hagan says that the role of Leo in The Go-Between was one of Michael Redgrave's great screen parts (LRB, 5 August), but Leo was played by Dominic Guard. Redgrave played the ageing Leo and was on screen for no more than four minutes. If we're talking about his great parts, Kipps, Fame Is the Spur or The Dam Busters would have been better examples.

The coroner’s report on Christopher Marlowe’s death is ‘at its most vivid’, Michael Dobson writes, ‘when it says that the wound was inflicted using a dagger “of the value of twelve pence"’ (LRB, 19 August). Until 1854 the value of the instrument of a man’s death had to be recorded in the coroner’s inquisition and, if the matter went to trial, in the murder indictment. The knife that killed Marlowe would have been seized as a deodand (‘that which should be given to God’), sold, and the proceeds used to support the dependants of the deceased.

In his review of my book History Play: The Lives and Afterlife of Christopher Marlowe, Michael Dobson, after quoting an extract from the blurb, writes of the cover image of the putative Corpus Christi portrait of Marlowe morphing into the Chandos portrait, supposedly of Shakespeare: ‘It is unfortunate for Bolt that the Corpus Christi portrait is very unlikely to be of Marlowe … and that the Chandos portrait is equally unlikely to be of Shakespeare.’ It is unfortunate for Dobson that he appears not to have penetrated History Play much further than the blurb and the cover. I make exactly that point about the Chandos portrait; and the exposure of the fragility of so many accepted ‘facts’ about Shakespeare is precisely the reason my book was written.

J.P. Roos, a defender of ‘evolutionary psychology’ (Letters, 19 August), may have half a point against Mulhall and Nussbaum: disgust probably does have some biological basis. But he fails to support the other half of his conclusion: that shame does, too. it’s possible to see the evolutionary advantageousness of disgust reactions to excrement, for example, but what is the evolutionary story that will explain the sense of shame felt by concentration camp inmates, rape victims or, indeed, public farters?

Most readers who enjoyed A.W. Moore's brisk demonstration that an arithmetisation of meta-mathematics produces provably unprovable propositions (LRB, 22 July) will have heard of Kurt Gödel, and some will recognise this as the work for which Gödel is famous. Without any mention of Gödel's theorem, however, Moore's article seems incomplete.

Andrew O’Hagan reports that John Kerry ‘taught himself to fly and had a go at looping-the-looop under the Golden Gate Bridge’ (LRB, 19 August). The roadway of the bridge is only 220 feet above water – lower than the Clifton Suspension Bridge. To attempt a loop in such a space would be suicidal. And how did Kerry teach himself to fly? Who leased (or loaned) an aeroplane to a man without a pilot’s certificate?

The Whitney Museum of American Art did not, as Gail Levin has it in her piece on Edward Hopper, ‘discard whatever it thought was Nivison’s’ (LRB, 24 June). The museum owns more than two hundred pieces by Hopper’s wife, Josephine Nivison. It loaned or gave many of her oil paintings to hospitals in New York City to hang in offices and reception areas. Some were discarded. However, the watercolours and a few oils have been kept in storage at the museum alongside works from the permanent collection. Though none of Nivison’s work is on display at the museum, four of her Whitney paintings are being loaned for a group exhibition that will open at Brigham Young University in January.

Spender’s nickname, ‘Stainless Splendour’, took me back to the years before the Second World War. As a treat I was allowed to stay up late on Saturdays to listen to the evening music-hall programme on the BBC. A frequent performer was Stainless Stephen. He was Arthur Baynes (1892-1971), a teacher from Sheffield. On stage he would be dressed in evening wear, a bowler hat and a stainless steel waistcoat.