Is anyone there? What the vegetative state asks of philosophy

Some of the hardest conversations I have overheard in our hospital in Cairo happen beside a bed where nothing seems to happen. A young man after a road accident, eyes open in the morning and closed at night, breathing on his own, sometimes moving his hands, never responding to his name. His mother asks the doctors the question every family asks: "Is he there?" The doctors answer carefully. I have no medical training, and I am not writing to second-guess them. I am writing because the question the mother asks is one of the oldest in philosophy, and medicine has made it urgent in a new way.

Awake but not aware

Doctors distinguish several conditions after severe brain injury. In a coma the patient is neither awake nor aware: eyes closed, no sleep and wake cycle. In what has long been called the vegetative state, now often renamed unresponsive wakefulness syndrome because the old name sounded insulting, the patient wakes and sleeps, opens the eyes, may grimace or move, but shows no reproducible sign of awareness of self or surroundings. In the minimally conscious state, a category defined by clinicians in 2002, the patient shows some definite but inconsistent signs: following a moving object with the eyes, now and then obeying a simple command.

Wakefulness and awareness, in other words, can come apart. That alone is a philosophical lesson. We usually assume that if someone's eyes are open and moving, someone is looking out of them. These patients show that the lights can be on while, as far as anyone can tell, nobody is home.

And "as far as anyone can tell" is doing a lot of work. Studies over the years have repeatedly found that a substantial share of patients diagnosed as vegetative, in some studies around four in ten, show signs of awareness when examined more carefully and more often. The diagnosis depends on the patient doing something we can observe. A person who is aware but cannot move would fail every bedside test.

The tennis experiment

In 2006 a team led by the neuroscientist Adrian Owen published a short report about a young woman diagnosed as vegetative after a road accident. Inside a brain scanner, she was asked to imagine playing tennis, and then to imagine walking through the rooms of her house. The regions of her brain that became active were the same ones that light up in healthy volunteers doing the same tasks. She could not move a finger. But, it seemed, she had understood the instruction and chosen to follow it.

Later studies used the same method as a channel of communication. Patients were told: imagine tennis for yes, imagine your house for no. A small number of patients diagnosed as vegetative were able to answer questions this way, correctly.

Philosophers will recognise the problem immediately. Thomas Nagel asked in a famous paper what it is like to be a bat, and argued that the subjective character of experience is something no amount of objective description captures. The vegetative state turns his question into a clinical one. The scan shows us activity. Whether there is anything it is like to be the patient is a further fact, and the scan reaches it only through an inference: this pattern, in a healthy person, goes with understanding, so perhaps it does here too.

A thought experiment from Ibn Sīnā

The Muslim philosophers had their own version of a mind cut off from its body. Ibn Sīnā asks us, in his work on the soul, to imagine a man created fully formed, suspended in the air, his eyes covered, his limbs held apart so that they touch nothing, perceiving nothing of the outside world. Would he know that he exists? Ibn Sīnā says yes: he would affirm his own existence without affirming any body. He used this "floating man" to argue that the self is something other than the body.

I don't want to claim too much. Ibn Sīnā was not thinking about brain injury, and his conclusion about the soul is a separate matter from any medical question. But his floating man and our patients share one disturbing feature: an awareness that may be complete on the inside and wholly invisible from the outside. If Ibn Sīnā is right that such a self is possible, then our bedside tests, which look for movement, are looking in the wrong place for the thing we most want to find.

What we owe the patient

This matters for decisions families and hospitals make every week: whether to continue treatment, how to speak in the room, whether to give pain relief to someone who shows no sign of feeling pain.

I have learned three things from listening to the doctors and from reading.

First, humility about absence. A negative bedside test does not show that nobody is there. It shows that nobody has been able to tell us. Many hospitals now advise staff to speak to these patients as if they can hear, and I think that is right even if most of them cannot.

Second, the burden of proof should be asymmetric. If we treat an aware person as absent, the wrong is grave. If we treat an absent person as aware, the cost is mostly some wasted courtesy. That is not a scientific conclusion. It is a moral one.

Third, the family's question, "is he there?", is not answered by the scan, and should not be presented as though it were. The scan can sometimes say "something is responding". It cannot say who. The card on philosophy of mind sets out why this gap may be permanent. In our tradition we say that God knows what is in the breasts. For the rest of us, at that bedside, it is enough to act as though someone might be.