Thursday 18 July 2019

Philosophy 102 - The Nature of Reality

To summarize my previous Philosophy-101 post, I exist, there is most likely some reality apart from me, and you, dear reader, probably exist as a mind separate from mine.  How's that for a recap?  Now let's explore a bit further into this supposed reality.

Maybe the "reality" as I perceive or experience the sensations coming into my mind bears no resemblance to what is actually outside my mind, in the "real world".  How can I know that I actually have hands and eyes, that what I "see" as I am apparently typing out my thoughts is indeed a computer screen with words on it and a black keyboard, along with opaque walls, transparent windows, etc.  Can I be certain that the noises I hear reflect traffic on the street or music in the next room?  Here too, all I have for certain are the sensations (or perceptions as John Locke calls them) coming into my mind.

As mentioned last time, I could be trapped in The Matrix, with a data stream generated by a super-AI feeding my brain stem.  At a different level, even assuming that these sensations bear some semblance to the "reality" around me, how can I be sure that the "real objects" they seem to represent are actually as they appear to my mind, are stable in time and space, and continue to exist as I see them now, when I am asleep or just away from this room?  Is there really anything behind the wall in front of me?  Is my wife really in the other room watching TV, or is this all some sort of Holodeck program for my confusion and deception?

In this regard, Bertrand Russell made a key observation in 1927: “We do not know enough of the intrinsic character of events outside us to say whether it does or does not differ from that of ‘mental’ events”, whose nature we do know.  He never wavered from this point.  In 1948, he noted that physics simply can’t tell us “whether the physical world is, or is not, different in intrinsic character from the world of mind.”  In 1956, he further remarked that, “we know nothing about the intrinsic quality of physical events except when these are mental events that we directly experience.”  In other words, our mental reality is the only reality we know for sure exists!

However, there is a high degree of coherence and consistency among the various aspects of the stream of sensations entering my mind.  When I reach out my hand and touch my desk, the position of my hand correlates well with the intention I had in moving it; the touch sensation of the hard surface is consistent with what I see and what I remember from the past.  If I tap on the desk, the sounds I experience are consistent, and if I press too hard, the pain I feel fits into the same overall mental picture or model.  When I remove my hand, the appropriate sensations occur on cue and are all consistent.  This applies regardless of what I do.  Even when I make a mistake or stumble, or something unexpected happens quickly, it all fits together, into a real, coherent perfection of virtual reality, if that is all it is!

What's more, in my interactions with the "other people" around me, they seem to be in the same reality as I am.  If I ask someone to pick up that book over there, they seem to hear my words, see the same book as I and understand what I want, and if they are agreeable, they can pick it up.  We both then see the same action occurring, albeit from different perspectives, and if we continued talking about our own sensations about the event, they would agree reasonably well.  Thus, other people seem to have a very similar view of the reality around them.  This suggests that there is indeed something real about that reality.  The two of us, and others as well, can navigate and operate in complex ways around the same objects and spaces, and interact with each other physically as well as verbally in very consistent ways.

The exceptions sometimes offered by philosophers just prove this point.  The stick in the water that appears to be bent due to refraction effects is seen the same way by anyone looking from the same position, and is well understood to be an exception to seeing a straight stick.  The same holds for optical illusions.  The very name says that we understand they are not representative of the true reality but are just artifacts of how our visual apparatus works.  We can usually explain the apparent abnormality in a cogent way, acceptable to most people.  Thus, these "exceptions" do not seriously undermine our models of the reality around us, nor our belief in its true existence and nature.  Indeed, one could say that magicians present stronger evidence against our models of reality when they fool us with their tricks.  But there too, we know they are not messing with reality, even if we don't know how they fool us.

This gets to my primary reason for accepting that our perceptions of the reality around us are fairly accurate, and that reality is, by and large, as we experience it.  The reason is that if there is any reality beyond our minds, then the apparatus we have for perceiving it is simpler if it is fairly accurate.  As an Engineer, I know that simple, semi-linear sensors, transducers and detectors are much easier to design, make and use than ones which send out signals (to our minds) that bear little resemblance to the reality they transduce or sense.  If reality existed, but was significantly different from the way we perceive it in our minds, then the intervening transducers and sensors would have to be extremely sophisticated.  Worse, the coordination among all these errant data streams would have to be continually correlated in complex, high-speed, non-linear ways in order to fool us into interpreting them as simple, yet consistent inputs for a coherent reality.

Evolution (if you believe in it) would surely adopt the approach that an accurate representation of the "real world" is better for survival than an inaccurate one.  If various people can get together and agree on the attributes of say, a table in front of them, and that say, a photo of the table seems to represent the same object, then the simplest hypothesis is surely that the reality is to a large extent as we perceive it to be.  How would evolution proceed to give us such a mental model of reality if that reality was totally different from the model generated in our minds?  Any biological equipment to do this latter would have to be very complicated, and could not arise by a series of simple evolutionary steps.  Of course, this particular argument assumes that we are indeed biological creatures, so perhaps it is merely begging the question.

Obviously we do not perceive reality perfectly or completely.  We cannot see in the dark, or detect radio waves or X-rays, we cannot accurately quantify the sensations we do detect in terms of decibels, brightness, intensity, force, taste, etc.  But most of what we see, touch and hear is most likely a reasonably accurate representation of what is around us; at least the parts of reality important to our continuing existence in the environment we find ourselves.  All people with normal colour vision will agree that this desk is brown, and that if we have only a red light in the room it will, of course, look red.  Imperfect perception does not imply perception that is totally wrong.

Another approach to this question might be to consider a new-born child.  Born into the world with no apparent mental model of reality, each baby must create and assemble her own such model, based on the sensations perceived by her developing mind.  This is a major undertaking, making babies the world's busiest scientists and philosophers!  What are these random blobs of shade and colour that I perceive somehow.  As I grow, I find that they go dark when I close my "eyes" (something that initially happens without my control).  Then I notice that when I move my "head" (also uncontrolled at first), everything shifts, but in a consistent way.  Later, I discover that these things waving in my visual field can be controlled, and eventually learn they are my "hands", which prove to be quite useful as I explore their movement and purpose.  In such a way, a child discovers her world and builds up her mental model of reality.  Of course, none of that is done consciously at first, making it even more likely that it is real.  But here too, perhaps this is just question begging since I am assuming that eyes, head and hands are actually real.

All of this still leaves open the possibility of a very clever virtual reality; that there is nothing apart from our minds and we are operating in a totally deluded state, either self-delusion, or generated by some other entity to deceive us.  For my best shot at getting past that hurdle, see Philosophy-101 again.  If other people truly exist, then we all occupy the same reality, or at least think we do.  A virtual reality capable of fooling billions of people, continually over decades of time, would be beyond anything we could do, and would raise the "why?" question.  What possible purpose would be served?  Yet, we cannot completely discount this possibility.  Nothing in reality can be proved or disproved absolutely!

The final option to reality being real, is that we are all part of some grand simulation somehow.  Like a vast video game, we are software constructs in some immense computer.  This staple of science fiction is taken seriously by many people, and cannot be totally disproved.  However, if this option is true, then the simulation would simply be our true reality, so that, once again, "reality" would be as we perceive it.  After all, even in our taken-for-granted reality, everything we see and do is just atoms and electromagnetic fields interacting, and we don't perceive things at that level.  So whether atoms or bits in a computer, our reality is as we perceive it.

Having attempted to solidify our belief in the reality around us, I should say that there is considerable and growing evidence that, at least at microscopic scales, reality only exists as such when we observe it!  Quantum physics experiments bear this out for photons, electrons, atoms, and even fairly large molecules.  Until we (or some mind) observes the experiment, or the interaction of these particles, the outcome remains a set of probabilities in superposition, that remain unexperienced, and so undefined or even in some sense, unreal.

This finding has serious and troubling implications for philosophy, science and consciousness.  When I close my eyes, does the computer in front of me continue to exist?  Is there really anything behind the wall in front of me if I am not actively thinking about it?  Such questions seem silly to most of us, but they are the sort of thing philosophers delve into.  And more and more, cosmologists and physicists are also considering questions like that.  That mind may be essential to the existence of reality is a serious topic of ongoing study and debate.

Nevertheless, like 99.999% of humanity (assuming such exists), I will go on believing that my mental model of the world around me fairly represents reality, and that the sensations I perceive are good representations of what is going on outside my mind.  I cannot prove that for certain, but little in life is certain, and the assumption surely makes life easier and more interesting.  In any case, these questions are fun to explore and discuss.

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