Whose Reality Is It Anyway?

Thomas Nagel wondered if the world a bat perceives is fundamentally different  to our own

By Keith Tidman

Do we experience the world as it objectively is, or only as an approximation shaped by the effects of information passing through our mind’s interpretative sieve? Does our individual reality align with anyone else’s, or is it exclusively ours, dwelling like a single point amid other people’s experienced realities?

 

We are swayed by our senses, whether through the direct sensory observation of the world around us, or indirectly as we use apparatuses to observe, record, measure, and decipher. Either way, our minds filter the information absorbed, becoming the experiences funneled and fashioned into a reality which in turn is affected by sundry factors. These influences include our life experiences and interpretations, our mental models of the world, how we sort and assimilate ideas, our unconscious predilections, our imaginings and intuitions unsubscribed to particular facts, and our expectations of outcomes drawn from encounters with the world.

 

We believe that what serves as the lifeline in this modeling of personal reality is the presence of agency and ‘free will’. The tendency is to regard free will as orthodoxy. We assume we can freely reconsider and alter that reality, to account for new experiences and information that we mold through reason. To a point, that’s right; but to one degree or another we grapple with biases, some of which are hard-wired or at least deeply entrenched, that predispose us to particular choices and behaviours. So, how freely we can actually surmount those preconceptions and predispositions is problematic, in turn bearing on the limits of how we perceive the world.

The situation is complicated further by the vigorous debate over free will versus how much of what happens does so deterministically, where life’s course is set by forces beyond our control. Altering the models of reality to which we clutch is hard; resistance to change is tempting. We shun hints of doubt in upholding our individual (subjective) representations of reality. The obscurity and inaccessibility of any single, universally accepted objective world exacerbates the circumstances. We realise, though, that subjective reality is not an illusion to be casually dismissed to our suiting, but is lastingly tangible.

In 1974, the American philosopher Thomas Nagel developed a classic metaphor to address these issues of conscious experience. He proposed that some knowledge is limited to what we acquire through our subjective experiences, differentiating those from underlying objective facts. To show how, Nagel turned to bats’ conscious use of echoed sounds as the equivalent of our vision in perceiving its surroundings for navigation. He argued that although we might be able to imagine some aspects of what it’s like to be a bat, like hanging upside down or flying, we cannot truly know what a bat experiences as physical reality. The bat’s experiences are its alone, and for the same reasons of filtering and interpretation, are likewise distinguishable from objective reality.

 

Sensory experience, however, does more than just filter objective reality. The very act of human observation (in particular, measurement) can also create reality. What do I mean? Repeated studies have shown that a potential object remains in what’s called ‘superposition’, or a state of suspension. What stays in superposition is an abstract mathematical description, called a ‘wavefunction’, of all the possible ways an object can become real. There is no distinction between the wave function and the physical things.

While in superposition, the object can be in any number of places until measurement causes the wavefunction to ‘collapse’, resulting in the object being in a single location. Observation thus has implications for the nature of reality and the role of consciousness in bringing that about. According to quantum physicist John Wheeler, ‘No ... property is a property until it is observed’, a notion presaged by the philosopher George Berkeley three centuries earlier by declaring ‘Esse est percepi’ – to be, is to be perceived.

Evidence, furthermore, that experienced reality results from a subjective filtering of objective reality comes from how our minds react to externalities. For example, two friends are out for a stroll and look up at the summer sky. Do their individual perceptions of the sky’s ‘blueness’ precisely match each other’s or anyone else’s, or do they experience blueness differently? If those companions then wade into a lake, do their perceptions of ‘chilliness’ exactly match? How about their experiences of ‘roughness’ upon rubbing their hand on the craggy bark of a tree? These are interpretations of objective reality by the senses and the mind.

Despite the physiology of the friends’ brains and physical senses being alike, their filtered experiences nonetheless differ in both small and big ways. All this, even though the objective physical attributes of the sky, the lake, and the tree bark, independent of the mind, are the same for both companions. (Such as in the case of the wavelength of visible light that accounted for the blueness being interpretatively, subjectively perceived by the senses and mind.) Notwithstanding the deceptive simplicity of these examples, they are telling of how our minds are attuned to processing sensory input, thereby creating subjective realities that might resemble yet not match other people’s, and importantly don’t directly merge with underlying objective reality.

  

In this paradigm of experience, there are untold parsed and sieved realities: our own and everyone else’s. That’s not to say objective reality, independent of our mental parsing, is myth. It exists, at least as backdrop. That is, both objective and subjective reality are credible in their respective ways, as sides of the whole. It’s just that our minds’ unavoidable filtering leads to the altering of objective reality. Objective reality thus stays out of reach. The result is our being left with the personal reality our minds are capable of, a reality nonetheless easily but mistakenly conflated with objective reality.

 

That’s why our models of the underlying objective reality remain approximations, in states of flux. Because when it comes to understanding the holy grail of objective reality, our search is inspired by the belief that close is never close enough. We want more. Humankind’s curiosity strives to inch closer and closer to objective reality, however unending that tireless pursuit will likely prove.

 

‘Mary’s Room’: A Thought Experiment

Posted by Keith Tidman

Can we fully understand the world through thought and language—or do we only really understand it through experience? And if only through experience, can we truly communicate with one another on every level? These were some of the questions which lay behind a famous thought experiment of 1982:

A brilliant neurophysiologist, Mary, knows all there is to know about her academic specialty, the science of vision: the physics, biology, chemistry, physiology, and neuroscience. Also how we see colour.

There’s a catch, however: Mary has lived her entire life in a totally black-and-white room, watching a black-and-white screen, and reading black-and-white books. An entirely monochromatic existence. Then, unexpectedly, her screen reveals a bright-red tomato.

What was it like for Mary to experience colour for the first time? Or as the Australian philosopher Frank Jackson asked, who originated this thought experiment, ‘Will [Mary] learn anything or not?’ *

Jackson’s original takeaway from his scenario was that Mary’s first-time experience of red amounted to new knowledge—despite her comprehensive scientific knowledge in the field of colour vision. Jackson believed at the time that colour perception cannot entirely be understood without a person visually experiencing colour.

However, not everyone agreed. Some proposed that Mary’s knowledge, in the absence of first-hand experience, was at best only ever going to be partial, never complete. Indeed, renowned philosopher Thomas Nagel, of ‘what is it like to be a bat’ fame, was in the camp of those who argue that some information can only be understood subjectively.

Yet, Mary's complete acquaintance with the science of vision might well be all there is to understanding the formation of knowledge about colour perception. Philosopher and neurobiologist Owen Flanagan was on-board, concluding that seeing red is a physical occurrence. As he put it, 'Mary knows everything about colour vision that can be expressed in the vocabularies of a complete physics, chemistry, and neuroscience.

Mary would not have learned anything new, then, when the bright-red tomato popped up on her screen. Through the completeness of her knowledge of the science of colour vision, she already fully knew what her exposure to the red tomato would entail by way of sensations. No qualities of the experience were unknowable. The key is in how the brain gives rise to subjective knowledge and experience.

The matter boils down to whether there are nonphysical, qualitative sensations—like colour, taste, smell, feeling, and emotion—that require experience in order for us to become fully familiar with them. Are there limits to our comprehension of something we don’t actually experience? If so, Mary did learn something new by seeing red for the first time.

A few years after Frank Jackson first presented the ‘Mary’s room’ thought experiment, he changed his mind. After considering opposing viewpoints, he came to believe that there was nothing apart from redness’s physical description, of which Mary was fully aware. This time, he concluded that first-hand experiences, too, are scientifically objective, fully measurable events in the brain and thus knowable by someone with Mary’s comprehension and expertise.

This switching of his original position was prompted, in part, by American philosopher and cognitive scientist Daniel Dennett. Dennett asserted that if Mary indeed knew ‘absolutely everything about colour’, as Jackson’s thought experiment presumes, by definition her all-encompassing knowledge would include the science behind people’s ability to comprehend the actual sensation of colour.

To these points, Mary’s factual expertise in the science of colour experience—and the experience’s equivalence and measurability in the brain—appears sufficient to conclude she already knew what red would look like. The experience of red was part of her comprehension of human cognitive functions. Not just with regard to colour, but also to the full array of human mental states: for instance, pain, sweetness, coldness, exhilaration, tedium—ad infinitum.

As Jackson ultimately concluded, the gist is that, given the special particulars of the thought experiment—Mary acquired ‘all the physical information there is to obtain about what goes on when we see ripe tomatoes, or the sky, and use terms like red and blue’—Mary did not acquire new information upon first seeing the red tomato. She didn’t learn anything. Her awareness of redness was already complete.

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* Frank Jackson, 'Epiphenomenal Qualia', Philosophical Quarterly, 32, April 1982.

The Anthropic Principle: Was the Universe Made for Us?

Diagram on the dimensionality of spacetime, by Max Tegmark

Posted by Keith Tidman

‘It is clear that the Earth does not move, and that it does not lie elsewhere than at the center [of the universe]’ 

— Aristotle (4th century BCE)

Almost two millennia after Aristotle, in the 16th century, Nicolas Copernicus dared to differ from the revered ‘father of Western philosophy’. Copernicus rattled the world by arguing that the Earth is not at the center of the universe — in a move that to many at the time seemed to knock humankind off its pedestal, and reduce it from exceptionalism to mediocrity. The so-called ‘Copernican principle’ survived, of course, along with the profound disturbance it had evoked for the theologically minded.

Five centuries later, in the early 1970s, an American astrophysicist called Brandon Carter came up with a different model — the ‘anthropic principle’ — that has kept philosophers and scientists debating its significance cosmologically and metaphysically. With some irony, Carter proposed the principle at a symposium to mark Copernicus’s 500th birthday. The anthropic principle points to what has been referred to as the ‘fine-tuning’ of the universe: a list of cosmological qualities (physical constants) whose extraordinarily precise values were essential to making intelligent life possible.

Yet, as Thomas Nagel, the contemporary American philosopher, suggested, even the physical constants known to be required for our universe and an intelligent carbon-based life form need to be properly understood, especially in context of the larger-scaled universe:

‘One doesn’t show that something doesn’t require explanation by pointing out that it is a condition of one’s existence.’

The anthropic principle — its adherence to simplicity, consistency, and elegance notwithstanding — did not of course place Earth back at the center of the universe. As Carter put it, ‘Although our situation is not necessarily central, it is inevitably privileged’. To widen the preceding idea, let’s pose two questions: Did the anthropic principle reestablish humankind’s special place? Was the universe made for us?

First, some definitions. There are several variants of the anthropic principle, as well as differences among definitions, with Carter originally proposing two: the ‘weak anthropic principle’ and the ‘strong anthropic principle’. Of the weak anthropic principle, Carter says:

‘… our location in the universe [he was referring to the age of the universe at which humankind entered the world stage, as well as to location within space] is necessarily privileged to the extent of being compatible with our existence as observers.’

Of the strong anthropic principle, he explained,

‘The universe (and hence the fundamental parameters on which it depends) must be such as to admit the creation of observers within it at some stage’.

Although Carter is credited with coining the term ‘anthropic principle’, others had turned to the subject earlier than him. One in particular among them was the 19th-century German philosopher Arthur Schopenhauer, who presented a model of the world intriguingly similar to the weak anthropic principle. He argued that the world’s existence depended on numerous variables, like temperature and atmosphere, remaining within a very narrow range — presaging Carter’s fuller explanation. Here’s a snapshot of Schopenhauer’s thinking on the matter:

‘If any one of the actually appearing perturbations of [the planets’ course], instead of being gradually balanced by others, continued to increase, the world would soon reach its end’.

That said, some philosophers and scientists have criticized the weak variant as a logical tautology; however, that has not stopped others from discounting the criticism and favoring the weak variant. At the same time, the strong variant is considered problematic in its own way, as it’s difficult to substantiate this variant either philosophically or scientifically. It may be neither provable nor disprovable. However, at their core, both variants (weak and strong) say that our universe is wired to permit an intelligent observer — whether carbon-based or of a different substrate — to appear.

So, what kinds of physical constants — also referred to as ‘cosmic coincidences’ or ‘initial conditions’ — does the anthropic principle point to as ‘fine-tuned’ for a universe like ours, and an intelligent species like ours, to exist? There are many; however, let’s first take just one, to demonstrate significance. If the force of gravitation were slightly weaker, then following the Big Bang matter would have been distributed too fast for galaxies to form. If gravitation were slightly stronger — with the universe expanding even one millionth slower — then the universe would have expanded to its maximum and collapsed in a big crunch before intelligent life would have entered the scene.

Other examples of constants balanced on a razor’s edge have applied to the universe as a whole, to our galaxy, to our solar system, and to our planet. Examples of fine-tuning include the amount of dark matter and dark energy (minimally understood at this time) relative to all the observable lumpy things like galaxies; the ratio of matter and antimatter; mass density and space-energy density; speed of light; galaxy size and shape; our distance from the Milky Way’s center; the sun’s mass and metal content; atmospheric transparency . . . and so forth. These are measured, not just modeled, phenomena.

The theoretical physicist Freeman Dyson poignantly pondered these and the many other ‘coincidences’ and ‘initial conditions’, hinting at an omnipresent cosmic consciousness:

‘As we look out into the universe and identify the many accidents of physics and astronomy that have worked together to our benefit, it is almost as if the universe must in some sense have known we were coming.’

Perhaps as interestingly, humankind is indeed embedded in the universe, able to contemplate itself as an intelligent species; reveal the features and evolution of the universe in which humankind resides as an observer; and ponder our species’ place and purpose in the universe, including our alternative futures.

The metaphysical implications of the anthropic principle are many. One points to agency and design by a supreme being. Some philosophers, like St. Thomas Aquinas (13th century) and later William Paley (18th century), have argued this case. However, some critics of this explanation have called it a ‘God of the gaps’ fallacy — pointing out what’s not yet explained and filling the holes in our knowledge with a supernatural being.

Alternatively, there is the hypothetical multiverse model. Here, there are a multitude of universes each assumed to have its own unique initial conditions and physical laws. And even though not all universes within this model may be amenable to the evolution of advanced intelligent life, it’s assumed that a universe like ours had to be included among the infinite number. Which at least begins to speak to the German philosopher Martin Heidegger's question, ‘Why are there beings at all, instead of nothing?’