‘Philosophical Zombies’: A Thought Experiment

Zombies are essentially machines that appear human.

By Keith Tidman

 

Some philosophers have used the notion of ‘philosophical zombies’ in a bid to make a point about the source and nature of human consciousness. Have they been on the right track?

 

One thought experiment begins by hypothesising the existence of zombies who are indistinguishable in appearance and behaviour from ordinary people. These zombies match our comportment, seeming to think, know, understand, believe, and communicate just as we do. Or, at least, they appear to. You and a zombie could not tell each other apart. 

 

Except, there is one important difference: philosophical zombies lack conscious experience. Which means that if, for example, a zombie was to drop an anvil on its foot, it might give itself away by not reacting at all or, perhaps, very differently than normal. It would not have the inward, natural, individualised experience of actual pain the way the rest of us would. On the other hand, a smarter kind of zombie might know what humans would do in such situations and pretend to recoil and curse as if in extreme pain. 

 

Accordingly, philosophical zombies lead us to what’s called the ‘hard problem of consciousness’, which is whether or not each human has individually unique feelings while experiencing things – whereby each person produces his or her own reactions to stimuli, unlike everyone else’s. Such as the taste of a tart orange, the chilliness of snow, the discomfort of grit in the eye, the awe in gazing at ancient relics, the warmth of holding a squirming puppy, and so on.

 

Likewise, they lead us to wonder whether or not there are experiences (reactions, if you will) that humans subjectively feel in authentic ways that are the product of physical processes, such as neuronal and synaptic activity as regions of the brain fire up. Experiences beyond those that zombies only copycat, or are conditioned or programmed to feign, the way automatons might, lacking true self-awareness. If there are, then there remains a commonsense difference between ‘philosophical zombies’ and us.

 

Zombie thought experiments have been used by some to argue against the notion called ‘physicalism’, whereby human consciousness and subjective experience are considered to be based in the material activity of the brain. That is, an understanding of reality, revealed by philosophers of mind and neuroscientists who are jointly peeling back how the brain works as it experiences, imagines, ponders, assesses, and decides.

 

The key objection to such ‘physicalism’ is the contention that mind and body are separable properties, the venerable philosophical theory also known as dualism. And that by extrapolation, the brain is not (cannot be) the source of conscious experience. Instead, it is argued by some that conscious experience — like the pain from the dropped anvil or joy in response to the bright yellow of fields of sunflowers — is separate from brain function, even though natural law strongly tells us such brain function is the root of everyone's subjective experience.

 

But does the ‘philosophical zombie’ argument against brain function being the seed of conscious experience hold up?

 

After all, the argument that philosophical zombies, whose clever posing makes us assume there are no differences between them and us, seems problematic. Surely, there is insufficient evidence of the brain not giving rise to consciousness and individual experience. Yet, many people who argue against a material basis to experience, residing in brain function, rest their case on the notion that philosophical zombies are at least conceivable.

 

They argue that ‘conceivability’ is enough to make zombies possible. However, such arguments neglect that ‘being conceivable’ is really just another expression for something ‘being imaginable’. Isn’t that the reason young children look under their beds at night? But, is being imaginable actually enough to conclude something’s real-world existence? How many children actually come face to face with monsters in their closets? There are innumerable other examples, as we’ll get to momentarily, illustrating that all sorts of irrational, unreal things are imaginable — in the same sense that they’re conceivable — yet surely with no sound basis in reality.

 

Proponents of conceivability might be said to stumble into a dilemma: that of logical incoherence. Why so? Because, on the same supposedly logical framework, it is logically imaginable that garden gnomes come to life at night, or that fire-breathing dragons live on an as-yet-undiscovered island, or that the channels scoured on the surface of Mars are signs of an intelligent alien civilisation!

 

Such extraordinary notions are imaginable, but at the same time implausible, even nonsensical. Imagining something doesn’t make it so. These ‘netherworld notions’ simply don’t hold up. Philosophical zombies arguably fall into this group. 

 

Moreover, zombies wouldn’t (couldn’t) have free will; that is, free will and zombiism conflict with one another. Yes, zombies might fabricate self-awareness and free will convincingly enough to trick a casual, uncritical observer — but this would be a sham, insufficient to satisfy the conditions for true free will.

 

The fact remains that the authentic experience of, for example, peacefully listening to gentle waves splashing ashore cannot happen if the complex functionality of the brain were not to exist. A blob that only looks like a brain (as in the case for philosophical zombies) would not be the equivalent of a human brain if, critically, those functions were missing.

It’s those brain functions that, contrary to theories like dualism, assert the separation of mind from body, that make consciousness and individualised sentience possible. The emergence of mind from brain activity is the likeliest explanation of experienced reality. Contemporary philosophers of mind and neuroscientists would agree on this, even as they continue to work jointly on figuring out the details of how all that happens.

The idea of philosophical zombies existing among us thus collapses. Yet, very similar questions of mind, consciousness, sentience, experience, and personhood could easily pop up again. Likely not as recycled philosophical zombies, but instead, as new issues arising longer term as developments in artificial intelligence begin to match and perhaps eventually exceed the vast array of abilities of human intelligence.

 

The Afterlife: What Do We Imagine?

Posted by Keith Tidman

‘The real question of life after death isn’t whether 

or not it exists, but even if it does, what 

problem this really solves’

— Wittgenstein, Tractatus Logico-Philosophicus, 1921

Our mortality, and how we might transcend it, is one of humanity’s central preoccupations since prehistory. One much-pondered possibility is that of an afterlife. This would potentially serve a variety of purposes: to buttress fraught quests for life’s meaning and purpose; to dull unpleasant visions of what happens to us physically upon death; to switch out fear of the void of nothingness with hope and expectation; and, to the point here, to claim continuity of existence through a mysterious hereafter thought to defy and supplant corporeal mortality.

And so, the afterlife, in one form or another, has continued to garner considerable support to the present. An Ipsos/Reuters poll in 2011 of the populations of twenty-three countries found that a little over half believe in an afterlife, with a wide range of outcomes correlated with how faith-based or secular a country is considered. The Pew Center’s Religious Landscape Study polling found, in 2014, that almost three-fourths of people seem to believe in heaven and more than half said that they believed in hell. The findings cut across most religions. Separately, research has found that some one-third of atheists and agnostics believe in an afterlife — one imagined to include ‘some sort of conscious existence’, as the survey put it. (This was the Austin Institute for the Study of Family and Culture, 2014.) 

Other research has corroberated these survey results. Researchers based at Britain's Oxford University in 2011 examined forty related studies conducted over the course of three years by a range of social-science and other specialists (including anthropologists, psychologists, philosophers, and theologians) in twenty countries and different cultures. The studies revealed an instinctive predisposition among people to an afterlife — whether of a soul or a spirit or just an aspect of the mind that continues after bodily death.

My aim here is not to exhaustively review all possible variants of an afterlife subscribed to around the world, like reincarnation — an impracticality for the essay. However, many beliefs in a spiritual afterlife, or continuation of consciousness, point to the concept of dualism, entailing a separation of mind and body. As René Descartes explained back in the 17th century:

‘There is a great difference between the mind and the body, inasmuch as the body is by its very nature always divisible, whereas the mind is clearly indivisible. For when I consider the mind, or myself insofar as I am only a thinking thing, I cannot distinguish any parts within myself. . . . By contrast, there is no corporeal or extended thing that I can think of which in my thought I cannot easily divide into parts. . . . This one argument would be enough to show me that the mind is completely different than the body’ (Sixth Meditation, 1641).

However, in the context of modern research, I believe that one may reasonably ask the following: Are the mind and body really two completely different things? Or are the mind and the body indistinct — the mind reducible to the brain, where the brain and mind are integral, inseparable, and necessitating each other? Mounting evidence points to consciousness and the mind as the product of neurophysiological activity. As to what’s going on when people think and experience, many neuroscientists favour the notion that the mind — consciousness and thought — is entirely reducible to brain activity, a concept sometimes variously referred to as physicalism, materialism, or monism. But the idea is that, in short, for every ‘mind state’ there is a corresponding ‘brain state’, a theory for which evidence is growing apace.

The mind and brain are today often considered, therefore, not separate substances. They are viewed as functionally indistinguishable parts of the whole. There seems, consequently, not to be broad conviction in mind-body dualism. Contrary to Cartesian dualism, the brain, from which thought comes, is physically divisible according to hemispheres, regions, and lobes — the brain’s architecture; by extension, the mind is likewise divisible — the mind’s architecture. What happens to the brain physically (from medical or other tangible influences) affects the mind. Consciousness arises from the entirety of the brain. A brain — a consciousness — that remarkably is conscious of itself, demonstrably curious and driven to contemplate its origins, its future, its purpose, and its place in the universe.

The contemporary American neuroscientist, Michael Gazzaniga, has described the dynamics of such consciousness in this manner:

‘It is as if our mind is a bubbling pot of water. . . . The top bubble ultimately bursts into an idea, only to be replaced by more bubbles. The surface is forever energized with activity, endless activity, until the bubbles go to sleep. The arrow of time stitches it all together as each bubble comes up for its moment. Consider that maybe consciousness can be understood only as the brain’s bubbles, each with its own hardware to close the gap, getting its moment’. (The Consciousness Instinct, 2018)

Moreover, an immaterial mind and a material world (such as the brain in the body), as dualism typically frames reality, would be incapable of acting upon each other: what’s been dubbed the ‘interaction problem’. Therefore the physicalist model — strengthened by research in fields like neurophysiology, which quicken to acquire ever-deeper learning — has, arguably, superseded the dualist model.

People’s understanding that, of course, they will die one day, has spurred search for spiritual continuation to earthbound life. Apprehension motivates. The yearn for purpose motivates. People have thus sought evidence, empirical or faith-based or other, to underprop their hope for otherworldly survival. However, modern reality as to the material, naturalistic basis of the mind may prove an injurious blow to notions of an out-of-body afterlife. After all, if we are our bodies and our bodies are us, death must end hope for survival of the mind. As David Hume graphically described our circumstances in Of the Immortality of the Soul (1755), our ‘common dissolution in death’. That some people are nonetheless prone to evoke dualistic spectral spirits — stretching from disembodied consciousness to immortal souls — that provide pretext in desirously thwarting the interruption of life doesn’t change the finality of existence. 

And so, my conclusion is that perhaps we’d be better served to find ingredients for an ‘afterlife’ in what we leave by way of influences, however ordinary and humble, upon others’ welfare. That is, a legacy recollected by those who live on beyond us, in its ideal a benevolent stamp upon the present and the future. This earthbound, palpable notion of what survives us goes to answer Wittgenstein’s challenge we started with, regarding ‘what problem’ an afterlife ‘solves’, for in this sense it solves the riddle of what, realistically, anyone might hope for.

The Decline of Materialism

Posted by Thomas Scarborough

Materialism is the theory that matter alone exists – however this is too simple. Let us assume, rather, that materialism is the arranging of our world in our minds – and since we are speaking of materialism, we do this on the basis of what we see, hear, smell, taste, and touch. 

That is, in speaking of materialism, we are speaking of all that we learn about a material world through our senses – either directly, or through the instruments which we use. And so defined, materialism may seem to promise us a complete understanding of our world. We have certainly made enormous strides. We are able to tease apart the sub-atomic world, see billions of years back in time, and map and manipulate the complex genetic code – among many other things. However, there are at least four limiting and complicating factors to a materialistic outlook, each of which vastly reduces its scope and its power:

• It is one thing to discover the laws of nature, yet quite another to predict their outcomes. We see an analogy in the game of chess. While the rules of the game are simple – a pawn advances like this, and a king like that – the outcome of these rules is another matter altogether. A chess board, which is simplicity itself in the scheme of things – a mere sixty-four squares and thirty-two pieces – taxes the human mind to the very limits of its powers. It is the easy part, one might say, to design a supercomputer, or to plot a trajectory to Pluto. The impossible part is to predict the ripples on a pond, or to anticipate the path of a snail on a wall. Worse than this, we too often fail to foresee the negative outcomes of laws we imagined we had mastered.

• If materialism is the arranging of a material world in our minds on the basis of what we see, hear, smell, taste, and touch, consider then that others, too, arrange the world in their minds – and these others enter my world and my considerations. It is not I alone now, who seek to arrange the world in my mind. As soon as I factor another human being into my thinking – let alone a few, even hundreds, not to speak of a million more – the complexity of knowing my world becomes unthinkable. It is beyond imagination on the graph of intrinsic complexity.  We therefore separate out such situations from the ‘natural sciences’, and call them ‘human sciences’. It happens wherever others enter the picture.

• The natural sciences are, in a sense, an open book. Yet in order to understand the human sciences, we need to understand how others arrange their worlds in their minds. In order to accomplish this, we now find that we need to understand how they communicate this – and we must infer it from semiotic codes.  A plethora of views, an ocean of feelings, vast beyond our comprehension, is expressed with facial expressions, nuances of speech, gestures, postures, behavioural codes, ideological codes, and so much more – all of them full of variation and caprice.  This takes us another quantum leap away from that materialism which advances through the senses.

• But the way that we use these semiotic codes, noted Jacques Derrida, we are continually deferring meaning.  Francis Bacon put it like this: words beget words (which beget words).  It is much like having money in a bank, which has its money in another bank, which has its money in another bank, and so on. It is easy to see that one will never access one's money. Which is to say that, while the things of sense seem concrete, our words merely hover over the surface of reality.  If mind and matter were to correspond in a one-to-one relationship, we would have to be mere ‘machines’. Yet suppose now that all living forms have such ‘hovering’ minds.  We may in fact be living in a vast, teeming world which is wakeful in every part.

Materialism, we said, is the arranging of our world in our minds, on the basis of what we see, hear, smell, taste, and touch. On the surface of it, this promises us a complete understanding of our world.  Yet then we come up against the problem of outcomes. Further, we come up against the problem of others – through which we separate out the human sciences. Then we discover that we need to engage with complex and subtle semiotic codes. And finally, we might need to account for a world which is populated not merely with seven billion human beings, but with living agents beyond number or knowing. One by one, each of these four steps, in quantum leaps, diminishes the usefulness of materialism. By and large, our advancing understanding of the world would seem to be taking us further and further away from the materialism the philosophers once knew.