What can an 11th century Islamic philosopher teach us about 21st century neuroscience?

There is a lot of fascinating research about the brain coming out of Stanford University, with some exciting, cutting-edge work being done there. Early last month I reported on the findings made by neuroscientists at Stanford in understanding how mental rehearsal prepares our minds for real-world action. Today, I’ll outline the recent advances made by a team led by Sergiu Pasca, MD, assistant professor of psychiatry and behavioral sciences at Stanford University, and discuss some of the ethical implications of this research.

Pasca’s method enables him to culture cells in order to form brain organoids with robust structures that are not compromised by cells from other parts of the body, thereby allowing him to more accurately replicate distinct brain regions. Doing so provides greater structural organization and also allows him and his team of researchers to better study and understand pathological mechanisms and perhaps one day to examine the molecular, cellular, and circuit levels of a person’s neurons. This is a promising method and a big step toward greater understanding of psychiatric and neurological disease, leading Pasca to declare, “This is our doorway into personalized psychiatry.” At the same time—although these “brain balls” are not brains, nor do they receive sensory inputs from the outside world—it is clear that as scientists progress in both the techniques and complexity of replication, major ethical questions and dilemmas will arise.

Chief among these will undoubtedly be the perennial ethical debate about the ontology of a human being. Is it only physical, material, social—in which case we might think of ourselves as technicians—or is it spiritual, religious, metaphysical—in which case we would more likely consider ourselves custodians? When we speak about attributing rights to animals or consciousness to AI, it is because at bottom we hold some fundamental belief: about dignity, a soul, being, or about what life might mean in a relational or social and emotional sense. This is no different with Pasca’s brain balls; in fact, it is an even more pressing quandary. As Bruce Goldman notes in his article, “One of the most amazing things about their brain balls was that, with not much chemical guidance, they tended to take on a default structure that’s a facsimile of the most evolutionarily advanced part of the brain: the human cerebral cortex, with all six layers you find in a living human brain.” The ethics of growing human organs are one thing, but the ethics of growing brain balls, which might eventually lead to more and more complex synaptic connections followed by even more elaborate renditions of an actual brain, will become especially contentious given the meaning and significance that we associate with the brain—both biologically and existentially.

One thousand years ago, one of the most preeminent philosophers and physicians of the Islamic world, Ibn Sina (d. 1037) developed a thought experiment called the “Floating Man” argument, in which he argues for the existence of a soul. Imagine that God creates a fully grown and mature human being out of thin air: he has no memory, no sensory input from any of his five senses, and he is floating in mid-air unable to feel the weight of his own body; what, if anything, would this floating man (or woman) be aware of? Ibn Sina contends that this person would still be aware of his own existence. Some might reject this intuition on the grounds that, instead of a soul, this floating person is actually experiencing brain mechanisms. Nevertheless, it still shows that self-awareness is somehow fundamental to all of our mental life.

When we consider new advances in neuroscience such as Pasca’s brain balls, we must also take into account the ethical implications—especially as it pertains to the essence of thought, consciousness, and self-awareness. For even Ibn Sina’s thought experiment suggests that pre-reflective awareness plays a role in distinguishing the soul or mind from the body. An empiricist understanding of the self and the world holds that everything that can be known ultimately derives from sense experience, whether either directly or indirectly, yet Ibn Sina’s floating man argument would seem to be a counter example to this. Regardless if one holds a purely empiricist view with focus on the material, or a religious view that believes in the immaterial and the unseen, the fact that the spheroids are not connected to sense-perception organs, for this precise reason, ought to make us take seriously Ibn Sina’s argument.

Beyond this, the thought experiment gives us pause to reflect on the genuinely unique and special nature of self awareness (as opposed to awareness of other things). This is significant even for a physicalist or materialists philosopher, because anyone who has a physicalist account of consciousness or the mind is still faced with the problem of explaining why it is that most people have these very strong intuitions about thought in that they cannot see how thinking could just emerge from some kind of physical body. Rather, consciousness seems to be this very special phenomenon, and accounting for why it is that it is so anomalous is the central problem that the physicalist faces. Thus the physicalist needs to argue for the possibility of consciousness and, moreover, they need an error theory of why it is that we walk around with either a belief in the soul (religions) or a matrix-like “ghost in the machine” (materialists).

Ibn Sina’s thought experiment, or intuition pump, reminds us that there is something special about self awareness; even if it doesn’t show that we’re not bodies, it might explain why it is that people have such a hard time accepting that they’re not only bodies. For we have this route of access to our own selves that we don’t have to anything else, which is a very important reality about our psychological makeup.

But philosophy is not everything. I’ve highlighted some of the ethical implications associated with such research as I expect that every new advance will invariably entail some sort of conversation about what constitutes life, how we construe meaning in the world, and even why it is that we continue to strive and aspire to produce great research. At least for now, the latter question has an easy answer. From Goldman’s piece on Pasca’s brain balls: “The spheroids enable researchers to zero in on the pathological mechanisms that disrupt fetal brain development in autism, epilepsy and other neurodevelopmental disorders. They can also help neuroscientists understand the causes of faulty brain development in prematurely delivered babies.” With noble intentions like these, I expect we will stay on the right track. But we should never forget about the past to help us steer the course.


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