With the news of Sodamn Insane’s execution plastered in big letters over the front pages of the new year weekend dailies (a strange phenomenon in itself), I realized that most of the world’s ancient execution methods do indeed go straight for the head.

• There is hanging, which we have seen. That internally severes the head from the body with the aid of gravity.
• There is decapitation, which of course completely severes the head from the body.
• There is the firing squad, which severely damages the head.

Interestingly, some of the more modern execution methods are exceptions.

• The electric chair, which burns the head but also internal organs.
• Lethal injection

But those were developed after acquiring a better understanding of biology and the development of modern technology. The central role that the head plays in sustaining life though, must have been very ancient knowledge indeed. Even predator animals know this, it seems, so it doesn’t surprise me that executioners of the pre-modern era needed no neuroscience to help in the task.

Excepting methods designed to cause suffering, execution methods demand a quick, possibly instantaneous end to life. This brings up the question of what constitutes death. Currently, the lack of EEG signals from the brain is considered the criterion of death. There are people who argue that only EEG signals from specific parts of the brain like the neocortex should be considered signs of life. I note that there also exists this very ill-defined notion of information theoretical death, which attempts to pin down yet another notion of life.

The difficulty appears to reside in finding out what is consciousness and where it resides. Does it reside in a particular part of the brain? Or perhaps in a particular state of the brain? And how complete must life be to be considered life? Some would argue that the body, as part of a connected system (whether neurologically or otherwise through various feedback mechanisms), is a part of consciousness as well. Yet clearly many parts of the body are not necessary for continued living, albeit in a disabled state; this is especially true with advancing medical technology, where replacements can be substituted for parts of the body.

Suppose the thought experiment goes further. Let’s start from the view of the pre-modern executioner who considers the head-body connection to be the last link of life. Let’s replace the entire interface from the head down with a life sustaining medical device, so you have a head-person. I didn’t come up with this idea, either. In any case, this is a fairly conceivable idea. But let’s go even further. People are doing neuronal simulation now. It is also conceivable that we can replace parts of the brain with machine-simulated parts. As long as the appropriate interface is preserved, there shouldn’t be a problem, right? So keep doing this, part by part. But wait a minute, at some point, there is so little biological material left that any notion of death — be it brain death, or information theoretic death, or whatever — must fail. And on the face of it, with mostly a machine simulation, the biological entity is dead, too, from an intuitive perspective. Yet, there should still be consciousness, should there not? There should not only be consciousness, but there should be the self-aware kind of consciousness that “I exist, I am still alive,” should there not? But what is the self and what is aware at this point? Is it not the machine?

This difficulty applies to natural death, too. We know neurons can live individually in the laboratory. Perhaps a rather large collection of them can even be kept alive with their internal connections. At what point does consciousness end at death? If a limb is chopped off, the severed neuron picks up the damage and passes the information to the brain, which acknowledges it. If a piece of the brain is chopped off, is not the remaining part of the brain aware of the damage if the two parts used to be connected? “Aware” in the most basic, objective sense, surely. If you chop off all parts of the brain, save for a few neurons which you then keep alive in the laboratory, do those neurons (or to put it in a more provocative way, do “I”) retain consciousness and the awareness that, ouch, I’m missing my other parts? Is the original person still alive in some sense?

When somebody is executed, it takes a few moments for neurons to die. In those few moments, there is no output from the body at all, because it is not possible, so as far as the interface with the outside world is concerned, the person is “dead,” “unconscious,” “not suffering any more.” But if the neurons are still alive for a few moments, and supposing they host the consciousness, do they the neorons (or, again, do “I”) “suffer” even as there is no way to detect it except perhaps to measure their EEG signals?

Isn’t there some argument over whether plants feel pain, or at least the chemical equivalent it, in a similar vein? Plants certainly don’t express pain in ways we are familiar. The problem with the plant pain is the “feel” part, of course, not the “pain” part, which is to say, it is again the difficulty with consciousness. What is consciousness. Is it an emerging phenonemon of all complex systems, as Kurzweil claims? This is hand-waving, of course… what is “emerging” and what is “complex,” but essentially this is a statement that consciousness doesn’t really exist and what we consider to be consciousness is just a description of the behavior of a complex system, and so if we must say where consciousness exists, it must exist in the collective state of the complex system, and not in a particular part of it. That takes care of the outward interface and what appears from the outside to be consciousness. But Gelernter makes a very good counterpoint to Kurzweil, which is that “emerging phenomenon” does not address the self-awareness problem at all. I’m going to take a jab at it.

Self-awareness is also an emerging phenomenon of the complex system. Do this thought experiment. Break the brain into two halves, let’s say A and B. To half-brain A, half-brain B is a complex system with the emerging phenomenon of appearing to be perfectly conscious. To half-brain B, half-brain A is a complex system with the emerging phenomenon of appearing to be perfectly conscious. By virtue of the connection between half-brain A and half-brain B, half-brains A and B both recognize the other as a conscious extension of its own system (biological plug-and-play, if you will), and thus is aware of it. But since to A, B is part of its own system and to B, A is part of its own system, the awareness of the other part really appears to be self-awareness, even though it isn’t truly “self”-awareness. Now take this argument down, down, down to single neurons, single molecules, single atoms, and any cut-set you want…

A chilling thought, if you toss this around a little bit. Especially if you consider what it means for death, suffering, and execution…