25 October 2022

Brains, Minds and Souls: What Is a Human Being?

by David Geelan | 25 October 2022 |

Is it possible, or will it become possible with technological advances, to ‘record’ a human mind into a computer? This might seem like a science or science fiction question, more than one appropriate for Adventist Today. Once we delve past some science and technology, though, it quite quickly becomes a question about what it means to be human, and what it means to have, or be, a mind.

Most people would agree, I think, that there’s a strong link between a brain and a mind. They’re not the same thing – a brain is a physical organ in the human body, a mind is something less tangible in some ways – but we tend not to imagine one without the other.

Minds, souls and bodies

Religious traditions – and philosophers like Plato – who believe that human beings are made up of a combination of an immortal, perfect soul connected during life with a mortal, corruptible body might believe that after death (and possibly before birth, at least in Plato’s case) the soul has a mind without having a brain.

Seventh-day Adventism has a different perspective – that the Divine breath connected with the earthly clay meant that Adam became a living soul, rather than being given a living soul. At death, the breath of life ceases and life ceases, and the resurrection is the beginning of a new life (with carried-over memories) rather than a continuation of an eternal life that had been ongoing during the body’s death.

I seem to have slipped from talking about minds to talking about souls. They, also, are not the same thing, but in some way, they are both ways of thinking about the essence of a human person. We might think, for example, that the essence of a person is not their body – which may change with weight gain or loss, tanning, surgery, amputation, illness or any of a range of other circumstances – but their mind. If the mind is impaired in some way, the personhood is not lost, but it is changed.

So, suppose we could ‘upload’ a mind to a computer, and it could function in very much the same way that it does in a brain. It could take in sensory input, cogitate on it and output actions or words. The computer would need some peripherals for sensing and action – perhaps a robot body, in humanoid or some other form. But would this entity be a human person, since it possesses a human mind?

Unimaginable complexity

Before we can wrestle with that question, it might be interesting to explore some of the technological hurdles that I leapt over too easily in setting up the hypothetical. The human brain is the most complex matter we know of anywhere in the universe – ‘fearfully and wonderfully made’ seems apt – and packs 86 billion neurons into a volume about the size of two closed fists. So creating a sufficiently powerful computer and a sufficiently capacious storage device is the first piece of the puzzle… but with terabyte harddrives in desktop computers and petabytes in data centers this days, and the processing power of multicore CPUs increasing rapidly, perhaps that seems more feasible than it might have even 10 years ago.

A second problem is the peripherals I mentioned: we have optical sensors nearly as complex as the human eye and with greater resolution and power, but most of vision doesn’t happen in the eye, it happens in the brain as the incoming visual data are combined, updated, interpreted, interpolated and made meaning of. Between the visual centers, memory and cognition, the processing of visual data is an enormously complex process.

Similar considerations apply to all our other senses, so offering our ‘mind in a machine’ the ability to sense – and to make meaning of what it senses – is far from trivial. And without the ability to sense and interact with the world, the mind would be doomed to a horrifying existence of thinking about only past experiences, with no way to communicate its thoughts to the world.

The third challenge is that our current semiconductor-based computers are binary – on or off, 1 or 0. Our brains operate in a much more ‘fuzzy’ and probabilistic way, where partial activation of a number of nearby neurons can ‘sum’ to activate a neuron. This is difficult or impossible to simulate accurately using a binary computer, at least without adding at least an additional layer of complexity in order to simulate something that’s already very complex indeed.

Quantum computing has the potential to better model probabilistic processes – that’s the key thing it’s good at – but is very much in its infancy.

So, even technologically, the idea of a mind being held and operating in something other than a human brain is some distance off yet, with a wide range of very difficult challenges to be solved.

The essence of being human

I’ll leave aside the ethical question of ‘If we could, should we?’ I think the answer would depend both on the quality of the experience for the mind in question and on each person’s individual views about the nature and sanctity of life and humanity.

The question, then, becomes ‘Is it even possible in principle?’ That is, assuming that we could solve the technological problems and that we concluded that doing so was ethically defensible, would it even be possible? Or would the ‘mind without a brain’ actually be something other than a mind, and something other than a human person?

Your answer is likely to turn on what you believe is the essence of being human, and what you believe is the essence of a mind. Is a mind something that is an emergent property of a brain once it surpasses a certain critical mass of ‘processing power’? Or is ‘mind’ something more, something divine or supernatural? Is mind something that can be bestowed only by the Creator, and is bestowed only on human beings (and, potentially, angels and beings on other worlds)? Or is mind simply the operation of a material brain?

These are interesting questions to ponder, and I hope you’ll have occasions to discuss them with friends or family.

But I think they also have some real implications for life. Because, at the bottom, thinking about what it means to be human leads me, at least, to realize that every other human being has a mind in the same way, of broadly the same kind, and is human in the same way I am. Fully recognizing our shared humanity is a crucial reminder of the truth so perfectly captured by John Donne: “No man is an island, Entire of itself. Each is a piece of the continent, A part of the main.”

Recognizing our common humanity is part of what motivates us to feed, cloth and care for ‘the least of these’ (Matthew 25), and to be as radically inclusive of people unlike us as Jesus was.

Dr. David Geelan is Sue’s husband and Cassie and Alexandra’s dad. He started out at Avondale College, and is currently Professor and National Head of the School of Education, within the faculty of Education, Philosophy and Theology at the University of Notre Dame in Sydney, Australia.