Stories of zombies, swamp-men, teleportation and aliens abound in Anglophone philosophy – and it’s easy to see why. When used effectively, “thought experiments” can illustrate a philosophical point, draw out intuitive assumptions for conceptual analysis, and engage an audience. They’re fun. At the same time they are often deeply disturbing. Take Sydney Shoemaker’s “brain transplantation” story (which appears in his 1963 monograph, Self-Knowledge and Self-Identity). It describes a horrible surgical mishap; in the not-too-distant future, an over-worked surgeon is operating on two patients simultaneously – Brown and Robinson – and mistakenly puts Brown’s brain in Robinson’s head. In Shoemaker’s tale, the survivor “Brownson” wakes up with first-person memories of Brown’s life and exhibits his character traits in Robinson’s body.
Since its appearance in the “personal identity” debate, Shoemaker’s story has been the subject of numerous commentaries and critiques. It implicitly assumes a mechanistic conception of the human organism (whereby bodies function like clocks, to be taken apart and reassembled at will), and it marginalises central embodied aspects of our character (how is Brown’s sexuality to be expressed in another body?). Not least among the concerns, is the worry that “brain transplantation” is so wacky an idea that it’s impossible to achieve any sort of reflective equilibrium; we simply can’t imagine a situation so bafflingly bizarre.
For those sympathetic to the last of these worries, recent claims by Italian surgeon, Sergio Canavero might well be of interest. In a TEDx Talk, and subsequent interviews with The Independent and The Mail Online, Canavero has said that he aims to perform the world’s very first human head transplantation. He claims to have developed a way of detaching, and re-attaching human heads, and plans to perform the procedure, which involves over 100 medical workers over 36 hours, within the next two years (in China if he is banned from doing so elsewhere). Similar operations were attempted on macaque monkeys and dogs in the 1970s, but the results were what might euphemistically be described as “unpromising” (the details are readily available on the Internet, for those with hardier constitutions than mine).
The reason for renewed interest in the project is the recent appearance of a volunteer willing to undergo the process. Valeri Spiridonov is a 30-year-old computer scientist with Werdnig-Hoffmann disease (the result of a genetic defect, which leads to severe muscular atrophy, and the fatal wasting away of his body); he views the operation, where his head will be put onto a donor’s body, as a way of potentially “continuing his life.”
Unsurprisingly, Canavero’s proposal has provoked anxiety both inside and outside the medical community. Dr Hunt Batjer, president elect of the American Association for Neurological Surgeons, views it with undisguised horror. “I would not wish this on anyone,” he says in The Independent, “I would not allow anyone to do it to me as there are a lot of things worse than death.” In the same piece, Arthur Caplan, director of medical ethics at New York University’s Langone Medical Centre, is reported to have described Canavero as “nuts”; even if the resulting body is biologically viable, Caplan and other experts worry that Spiridonov will be subject to “hitherto never experienced levels … of insanity.” The risks are high, and the news coverage is correspondingly frenetic.
What has not been discussed in the media narrative is whether or not the post-operation patient will in fact be the same person as Spiridonov (assuming the procedure is a “success”). Will he be the same individual (assuming the body donor is male)? Is the project ethically defensible? To answer these and related questions, TPM has enlisted the help of seven philosophers whose work has touched on questions of personal identity and transplant thought experiments: Lynne Rudder Baker (University of Massachusetts Amherst), Eric Olson (University of Sheffield), Susan James (Birkbeck College), Stephan Blatti (University of Memphis), Giovanni Boniolo (University of Milan), Cédric Brun (Bordeaux-Montaigne University), and Derek Parfit (All Souls, Oxford).
The first point of contention among these experts is what exactly to call the procedure. The newspapers have named it a “head transplant,” but Lynne Rudder Baker suggests it “might be more aptly called a ‘body transplant’.” Eric Olson, by contrast, thinks it would be a case of “brain donation” (or “head” donation). What is the basis for this disagreement? Roughly speaking, Rudder Baker endorses a neo-Lockean, “psychological” account of personal identity – she believes that our persistence depends on psychological continuity, and since the brain/head is the seat of our consciousness it serves as an individuative nucleus for our survival. Olson, on the other hand, is an “animalist”; he believes that we are fundamentally human animals, and that our living activity, rather than psychological continuity, is the grounds for our persistence. As Rudder Baker puts it:
“An animalist might say that a person survives, but that he is not Spiridonov; the survivor is the person who had the brainless body (that presumably was alive at the time of the transplant). An animalist should say that the person goes with the body. A neo-Lockean might say that a person survives, and that he is Spiridonov; the survivor is the person who had the head (or brain).”
Olson’s animalism, then, contrasts with the media coverage of the story: “[Spiridonov] is mistaken in believing that the operation could save his life. At best it would save the life of the man whose brain would be removed to make room for his. He’s effectively agreeing to donate his brain to someone else, though he doesn’t realise this.” And while our other consultants don’t necessarily endorse this animalist position, they are certainly circumspect about whether or not the result of a “successful” operation would be the same person. Giovanni Boniolo doubts we can decide either way, and even Rudder Baker is chary: “I would … say that we just don’t know whether the survivor would be Spiridonov-vastly-changed, or someone else.” Stephan Blatti similarly holds that “even if the operation is successful (in the strongest possible sense), there just is no fact of the matter about what will become of Mr. Spiridonov.…”
It is telling, perhaps, that when faced with a case like this, outside the rarefied environs of the seminar room, the focus is not on the metaphysical status of the individual but rather on the ethical and cultural repercussions of the surgery. Continuing his thoughts above, Blatti says that “[u]ltimately, the sort of challenge that his case raises is practical in nature: we as a society have a decision to make about how to regard the being that results from this procedure.” Olson says that if the story “has philosophical interest, it’s to do with whether it would be worth living in that sort of state.” What sort of state is that? An epistemologically impoverished one, where the resulting patient would have a painfully hard time knowing exactly what sort of thing it is. If Canavero’s dream becomes a reality, we are all going to have to reassess traditional models of subjectivity – we are all potential subjects of such an operation. As Susan James puts it:
“Culturally, such a transplant would put pressure on the idea that a person is their embodied brain – i.e. that particular brain in its body. It’s a fair guess that we’d say that X before transplant was X after transplant. But X and everyone else would have a hard time working out who X was. We tend to assume in our thought experiments that when X’s brain is put into Y’s body, X inherits Y’s memories. But would this be the case? Perhaps, as some of the critics suggest, there would just be a buzzing blooming confusion.”
If Canavero manages to fix Spiridonov’s head to another individual’s body then the way we conceive of ourselves, of the relation between the subject and the subject’s body-parts, will be open to radical reconception. Perhaps it will draw us towards a Cartesian image of a mechanical body, composed of infinitely replaceable parts. Perhaps it will move us away from the image of the liberal human subject, into a post-gender world, opening up new spaces, as James points out, for interesting “transgender possibilities.”
Whatever the case, the realisation of Canavero’s experiment does not – Blatti says – stand as any kind of argument for the neo-Lockean position. Many people – including Spiridonov – may have the intuition that, if his psychological traits, beliefs, memories, and so on, become instantiated in the new body, “then Mr. Spiridonov himself will seem to have become separated from his old body and will seem to have acquired a new body…”
“…[b]ut having such an intuition is the beginning of the debate, not the end of it. After all, philosophers will also concede that we have intuitions, hunches, pre-reflective thoughts, instincts, etc. about lots of things, which, upon closer inspection, turn out to be false. So the question that is hotly disputed today is how reliable the transplantation intuition is. And in the contemporary personal identity debate, a wide range of positions is defended. Some philosophers regard the transplant intuition as tracking the truth, whilst others deny it outright. Some philosophers work to explain it away, while others regard it as capturing an important ethical truth but not strictly speaking, a truth about the identity of persons.”
With respect to Spiridonov, this is, of course, wild speculation. There is absolutely no guarantee that Canavero will be successful; indeed, there is general confusion about what “success” would even mean in this context. If the resulting individual regains conscious what’s to say they will not simply be what David Wiggins described as a “gruesome mess,” a melange of terror and confusion? Cédric Brun thinks the “patient’s life would be hell for some time. The subject would suffer. He wouldn’t be geared in the right way to his body, and the discrepancy between how he thinks about himself and his body would be very difficult to understand.” It is interesting that in recent years, Shoemaker has altered his thought experiment so the transplantation occurs between identical twins, or clones, but this will not be the case with Spiridonov. “How will he understand an itch on his new arm?” Brun asks, “The kinaesthetic issues would be major. I imagine he would experience severe body agnosia – he may well cease to associate with his body-parts.” Any which way, Spiridonov is taking an incredible risk.
“This,” Brun says, “is what happens when armchair philosophy becomes reality. The reverse is much safer,” he adds, wryly. “You can put any kind of empirical data into the hands of philosophers and it won’t hurt anyone.”
Given the risks, is Canavero’s proposal ethically defensible? Brun, for one, thinks that without further research these plans are irresponsible and morally suspect. “There is no real animal model, there is no computational model of this neuro-surgical operation. We need to get some background research in place first – let’s try it again on a mouse, or a macaque before we start trying it on humans.” Rudder Baker is similarly dubious – it’s certainly not defensible yet, she says, “maybe not ever – it seems like opening a Pandora’s Box.” And James agrees: “If the article is right there’s huge scepticism among other experts. So it’s probably too soon to be trying this experiment – and there’s a possibility of doing huge harm to the patient. Alongside the ethical defensibility question is another: why this urge to sustain life at all costs? I think that might be the more interesting thing to concentrate on.”
Derek Parfit, on the other hand, states that “[i]f this other person had just died, perhaps through irreversible brain damage, I don’t believe there could be a good objection to this head transplant.” And Boniolo suggests that though society might not be ready for this kind of operation, it might be defensible “from the point of view of the autonomy of the individuals involved.” If Canavero and Spiridonov both agree willingly and freely to partake of this medical contract, then there are no grounds to prevent them. Blatti treads a middle ground here, recognising the importance of scientific investigation, while simultaneously cautioning against the risks:
“It is vital to the success of scientific inquiry that we be open to new ideas and procedures, even when they might initially strike us as radical. What is crucial is (a) that the participants in this research and experimentation do so freely and with maximal knowledge about what they’re letting themselves in for and (b) that there is minimal risk of harm to those who have not elected to participate. With these considerations in mind, there is, so far as I can tell, no reason to impugn this experimental surgery on ethical grounds. I hasten to add that this does not mean that I think it prudent or wise for Mr. Spiridonov to consent to the procedure. Just because one can do something doesn’t mean one ought to do that thing…”
Given all this, could any of the experts imagine undergoing the procedure? Brun ventures that he might: “If I had a mortal disease, which I had very little chance of surviving, I would take the risk – with the disclaimer that I can be euthanised at any moment of my choosing afterwards.” Olson is cautious: “I don’t know… [W]ould I agree to donate my brain? … [W]ould I agree to donate the rest of me? If the alternative in each case were death, the answer would depend on whether the resulting person would have a life worth living. That’s an empirical question that no one knows the answer to.” Parfit, interestingly, abstains from answering – but the rest are categorical in their response. “Never in a million years,” says Blatti. “Not at all,” declares Boniolo. “Absolutely not,” says James, “I hope I’m going to find the courage to resist major medical interventions when the time comes to die.” “No,” says Rudder Baker, “I would prefer death … to risking a ‘hitherto never experienced level and quality of insanity’.”