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Is Human Understanding Fundamentally Limited?

Updated on July 24, 2017
John Paul Quester profile image

Paul is a mostly retired academic; he holds advanced degrees in philosophy and psychology.

Consciousness - 17th Century
Consciousness - 17th Century

On the Hard Problem of Consciousness

“How it is that anything so remarkable as a state of consciousness comes about as a result of irritating nervous tissue, is just as unaccountable as the appearance of the djinn when Aladdin rubbed his lamp in the story.” This arresting simile, penned by Thomas Huxley (1825-1895), the English biologist dubbed 'Darwin’s bulldog’ for his spirited defense of the theory of evolution, vividly captures the disconcert that the problem of nature and origin of consciousness elicits in any thinking person who delves into its complexities.

The last few decades have witnessed dazzling empirical and technological advances in the neurosciences, which have significantly enhanced our understanding of the brain. This progress, including the ever more accurately mapped dependency of conscious mental functions upon specific neural structures, has engendered in the general public a widespread impression that the ‘physicalistic’ view of the mind-brain nexus has been conclusively validated: the view, that is, that neural activity causes conscious mental activity, and that the latter is itself a purely physical process.

But this is not the case. Despite remarkable progress in the neural sciences, the conceptual conundrums raised by consciousness, and more generally by the mind-brain relationship, remain as puzzling as in Huxley’s time. That a series of entirely unexceptional physical processes taking place within and between the brain’s neurons could result in conscious mental states - such as the sensation of redness, or of softness, or of cutaneous pain - which seem qualitatively different from these process, creates an explanatory gap extremely difficult to close.

Promissory Materialism

Still, perhaps a majority of neuroscientists cling to the view that over time this seeming impassable chiasm will be bridged as a result of the steadily increasing scientific understanding of brain activity. Philosopher Karl Popper referred to this position as ‘promissory materialism’ given its 'promise' that the mind will be ultimately ‘reduced’ to - that is fully explained by - purely physical processes.

Others so despair that we will ever understand this relationship that they choose to regard consciousness as illusory, as something unreal, which as such needs no explaining. Others yet argue that although mind is ultimately dependent upon the brain and arises from it, cannot itself be reduced to neural activity, but possesses a reality and causal efficacy of its own. Others still claim, as the French philosopher Descartes (1596-1650) long ago posited, that matter and mind are two essentially different - though interacting - types of substances, the 'mind' thus defined closely resembling the ancient notion of 'soul' (see also my ‘What on Earth Happened to the Soul?)

At present, the theoretical difficulties associated with each such position are generally regarded as substantial.


Enter the New Mysterians

This impasse has led a number of influential contemporary thinkers to independently attack the problem from a different angle; philosopher Owen Flanaghan has dubbed them the 'New Mysterians', (after the 1960’s pop group 'Question Mark and the Mysterians'). Arguments supportive of this position have been advanced by Colin McGinn, Steve Pinker, Noam Chomsky, and several others.

In broadest terms, the mysterians propose that we may never solve the 'hard problem of consciousness' because its complexities far exceed our cognitive resources: we just ‘ain’t smart enough’ to crack this problem. Why not? Because we share with all other animals the modalities of the evolutionary process. As such, our cognitive traits as mediated by the brain result from random genetic mutations and selective pressures. And, since all other species exhibit obvious cognitive limitations, there is no reason to exempt our own from being similarly constrained: 'unless we are angels’, Noam Chomsky quipped. The great linguist proposes that in science we should distinguish between problems and mysteries. Problems can be solved; mysteries such as the origin and nature of consciousness are in principle unsolvable due to impassable cognitive limitations resulting from the brain’s evolutionary history, structure and function. No matter how hard it tries, a rat will never learn to negotiate a maze which requires it to turn left at every fork that corresponds to a progression of prime numbers (2, 3, 5, 7, 11, 13, 17, 19, 23, etc.) Our situation vis a vis some scientific mysteries is not unlike that of a rat facing that maze.

The Milky Way
The Milky Way | Source

Unsolvable Mysteries?

Some readers may find this position unduly pessimistic and even disturbing, and some philosophers, Daniel Dennett most notably, have strenuously objected to it. Still, a moment of self-reflection should persuade us of its prima facie plausibility.

Consider, for instance, how limited the capacity of our short term memory is: you probably will not be able to repeat in the appropriate order this sequence of digits: 8, 324, 65, 890, 332, 402, 545, 317. The episodic division of our long term memory is similarly limited: can you remember what you had for dinner exactly three weeks ago? Not likely (unless, that is, your menu never changes...). And more: we can perceive sound frequencies between 20 and 20000 Hz at best, which means for instance that our dogs can hear sounds well beyond our auditory range; and we perceive as light only an extremely limited sliver of the electromagnetic spectrum. Also: can you form a mental image of a five-dimensional space? No. These simple examples show that basic cognitive capabilities such as memory, perception, visual imagination, are severely limited. Why should our ability to think not be similarly constrained?

Admittedly, through theoretical thinking we have managed to transcend the narrow representation of the world induced by the senses. Also, by developing specialized languages we have been able to bypass the constraints of sensory- based intuition and imagination (for instance, mathematicians have no problems characterizing multidimensional spaces). But in the end, the notion that our thinking skills are exempt from the limitations affecting our other cognitive abilities – and of those of all other species - introduces a radical discontinuity in this domain that is hard to justify.

At this juncture it is important to point out that although the mysterian viewpoint emerged largely from the difficulties associated with the understanding of consciousness, it can be generalized to a number of key scientific issues.

Is Science Coming to an End?

Science writer John Horgan expounded in his book The End of Science (1996; 2015) the controversial thesis that science as we know it may be approaching its end. Horgan contends that the key discoveries in the natural sciences, from quantum mechanics and relativity in physics to evolution and the mechanisms of heredity in biology, to name but a few, have been made once and for all. There is of course ample room for a more complete understanding of many phenomena in these domains, for the further accumulation of empirical data, as well as for the development of increasingly sophisticated technologies. But it is unlikely, Horgan argues, that these key theories will be superseded by radically new ones. Again, this does not mean that there are no problems left for science to study: far from it. But the deeper problems (Chomsky’s mysteries), such as the origin of life, the nature of consciousness, the origin of natural laws, the question of whether or not there are multiple universes, and so on: these problems are most likely to remain unsolved because they exceed the theoretical, empirical, and technological grasp of human science. Creative scientists will never give up trying to solve these mysteries, as shown by an unending stream of ever more 'exotic' ideas about the physical world. But this kind of theorizing cannot be regarded as scientific: for the many competing theories proposed often cannot - either in principle or due to unmatchable technological challenges - be empirically tested. When addressing these most fundamental problems, science become increasingly similar to philosophical speculation. His main function is not to establish truths, but to remind us of the limits of human knowledge.

Absurd! And Yet...

Needless to say many scientist found this claim professionally unacceptable and quite simply false. But Horgan’s thesis should not be too hastily dismissed. For instance, as it is well known general relativity and quantum mechanics, the two fundamental bastions of contemporary physics, as currently formulated are mutually incompatible. Attempts to articulate a testable new theory, the so called theory of everything, that would transcend this incompatibility and allow to deduce the whole of physical reality from its basis have not been met with success despite decades long attempts by the best minds in the field. A number of elite scientist believe that such a theory may never be arrived at.

To give yet another example, quantum mechanics is the most successful physical theory ever devised, having passed every stringent test it has been subjected to. It is also at the basis of several key technological developments. Yet, although the mathematical apparatus of the theory has proved extremely accurate in accounting quantitatively for all phenomena within its domain of applicability, and despite the fact that the theory is now more than a century old, there is no large consensus among physicists about the physical meaning of the theory. No consensus, that is, about the ultimate nature of the physical reality to which it points. And few experts hope that things may change any time soon. For instance, British physicist Issam Sinjab reported in a recent post on Research Gate that at a conference in Austria in 2011, 33 leading physicists, mathematicians and philosophers of science were administered a multiple choice based questionnaire about the physical meaning of quantum mechanics. The results showed a substantial lack of agreement. Moreover, 48% of the participants thought that a repeat of this meeting 50 years from now would produce similar results; only 15% were more optimistic.

Within mathematics, it was long assumed that a complete and consistent system of mathematical statements could in due time be achieved, in which every such statement (or its negation) could in principle be proven to be true. However, Godel’s incompleteness theorem (1931) showed that in any given formal system, statements can be formulated that are true within the system, yet cannot in be proven to be true within that same system.

This list could continue.

Can We Get Smarter Yet?

Let us assume that the mysterians’ thesis: that our current limitations as an animal species prevent us from solving the deepest questions about the ultimate nature of reality, is basically correct. Could this state of affairs ever change? Could we ever become smart enough to tackle these problems successfully?

The 'Flynn Effect'

Research on human intelligence as measured by psychometric tests has uncovered the so-called 'Flynn Effect'. The term refers to the significant and sustained increases over time in both main types of human intelligence: fluid (the ability to solve novel cognitive problems largely based upon one’s sheer ‘brain power’) and crystallized (the ability to effectively deploy our knowledge, learned skills, and experience in our life and work). A nearly linear increase in IQ has been observed in many countries, and over a period of nearly a century in the West. The duration of this effect though historically significant is much too short to be explained by genetic factors. Rather, it appears to result from socio-cultural factors, such as improvements in nutrition, education, health care, environmental stimulation, and decreasing family size.

Although the Flynn effect only measures increases in average intelligence, one could find reason to also expect an increasing ability to solve difficult problems as we progress into the future. However, there are indications that the growth of IQ in advanced countries may be coming to a halt, or be slowing dramatically. Still, the national average IQ of some developing countries is still increasing, no doubt due to the improvement of the factors mentioned above. Accordingly, as more and more people worldwide gain access to advanced educational opportunities, there is reason to expect that the number of supremely gifted individuals capable of ground breaking discoveries in key fields will likely increase, thereby potentially leading to substantial scientific and intellectual progress.

We Are Still Evolving

We should also bear in mind that human biological evolution has not ceased. On the contrary, humans are evolving faster than ever, largely due to the size of the growing world population. Note that the largest evolutionary changes in our species have taken place at the level of the neocortex - the seat of all advanced cognitive functions - and this is likely to continue. The physical expansion of the brain has been limited by the size of the skull, which is in turn constrained by the size of the pelvis, through which the neonatal head must pass. Since large brains and a narrow pelvis are both adaptive (brain size and intelligence appear to be positively correlated, albeit modestly, and a small pelvis facilitates a biped’s erect position and locomotion) the female body evolved preserving both, while maximizing neither. However, as suggested by some evolutionary biologists, the increasing worldwide use of caesarean sections (according to some data 48% of all births in Cina, and about 30% in the United States are caesarean) may partially overcome that evolutionary balancing act by enabling the survival of more babies with bigger heads and/or narrower pelvis. Indeed, according to recent findings, today’s newborns have slightly larger heads than those borne about 150 years ago. It is certain however that beyond a point the increase in head (and therefore brain) size will be limited by other factors.

The above illustrates an interaction between biological and cultural evolution that could lead over time to significant changes in our species, including those involving its problem solving potential. In the extreme case, humanity could eventually decide to take active control of its own evolution via direct manipulation of its DNA. Needless to say, enormous scientific and ethical challenges would have to be faced and met.

Human vs Machine Intelligence

Some philosophers and AI scientists claim that in the not too distant future intelligent machines will be developed that vastly exceed humanity’s most advanced and creative cognitive powers. In this scenario, then, the ultimate scientific questions may be solved by this advanced form of artificial intelligence.

If these machines are still to be conceived and designed by humans, though, it is doubtful that they would be able to qualitatively bypass the cognitive strictures that constrain also the less ‘mechanical’ aspects of human thinking.

Unless, that is, by taking control of their own evolution – already and increasingly computer software can write and debug itself – these machines could eventually produce a type of mind radically different from our own. If this scenario came to pass, though, we could find ourselves in a disagreeable position. If, as it has been noted, tomorrow’s computers and their descendents were to decisively outsmart us, chances are we would not be able to understand their discoveries. We could benefit from them and their technological derivates, but would not be in a position to grasp them conceptually. This would make us not unlike our pets, who have adjusted to their masters’ behavior and environment and learned to take advantage of it, but remain unable to understand most of it. Not a cheerful prospect.


In sum, I see merit in the view that our present cognitive resources are limited; but it is just possible that, if our species will continue to evolve and flourish both biologically and culturally, our distant successors may yet come to understand a lot more of the ultimate mysteries of our world than we currently do.

However, there is another side to this story. Imagine that we were to find answers to all the questions that occupy us in our most exalted moment. Including that most fundamental of all questions that, it has been said, is so profound that only children and the most hubristic metaphysicians dare posing, namely: why is there something rather than nothing?

What then? No more mysteries. No more surprises. The world’s shadows forever chased away by the light of triumphant Reason. How wonderful. Or is it? Could it be that, the sense of mystery, awe, and wonder that drives even the least inquisitive among us having been satisfied; our self imposed task to make dumb matter aware of itself through us having been accomplished: could it be that we would come to feel that there is little of real importance left for us to do in this world? What then?

Oh, one more thing. In this hub I considered human knowing in its most rational mode: the kind best exemplified by the methods of the natural sciences. But, some people argue, there may be another side to us humans, as hard to know as the dark side of the moon. Across all cultures and historical times, some individuals claimed to have found paths to absolute knowledge by way of non ordinary cognitive and experiential practices that for want of better term can be called 'mystical'. Is there a part of us, beyond the more familiar one, which can gain direct access to ultimate reality, and as such is unconditioned by the constraints of discursive ways of knowing?

Unlikely, admittedly. Yet deserving of some consideration.

A good topic for another hub.


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      eligible 6 months ago

      As the question appeared, we experiences daily that human mind have no limitations because all happenings and development comes through this human mind. some body called it human machine but we know that all machines have limited capacity accept our mind, we started working on artificial intelligence , it will be workable and possible, it's our mind which can make every thing possible.