Class Warfare Blog

September 18, 2019

More on Senses (Can We Trust Them?)

Filed under: Philosophy,Reason,Science — Steve Ruis @ 11:35 am
Tags: , ,

This topic struck a nerve, to some extent, And, it may be a manifestation of “the green car effect” but having written recently about whether we can trust our senses, I ran across the following book. Here are the title, author, and’s blurb for that book:

The Case Against Reality: Why Evolution Hid the Truth from Our Eyes by Donald Hoffman

Can we trust our senses to tell us the truth?

Challenging leading scientific theories that claim that our senses report back objective reality, cognitive scientist Donald Hoffman argues that while we should take our perceptions seriously, we should not take them literally. How can it be possible that the world we see is not objective reality? And how can our senses be useful if they are not communicating the truth? Hoffman grapples with these questions and more over the course of this eye-opening work.

Ever since Homo sapiens has walked the earth, natural selection has favored perception that hides the truth and guides us toward useful action, shaping our senses to keep us alive and reproducing. We observe a speeding car and do not walk in front of it; we see mold growing on bread and do not eat it. These impressions, though, are not objective reality. Just like a file icon on a desktop screen is a useful symbol rather than a genuine representation of what a computer file looks like, the objects we see every day are merely icons, allowing us to navigate the world safely and with ease.

The real-world implications for this discovery are huge. From examining why fashion designers create clothes that give the illusion of a more “attractive” body shape to studying how companies use color to elicit specific emotions in consumers, and even dismantling the very notion that spacetime is objective reality, The Case Against Reality dares us to question everything we thought we knew about the world we see.

It’s a frickin’ conspiracy that is what it is!

Uh, no. I have not read this book and probably will not and while the author may not have written the blurb but there are a number of things disturbing about it. For one “Challenging leading scientific theories that claim that our senses report back objective reality . . .” WTF? What “leading scientific theories” are these? I am aware of none of these. The literature on optical illusions goes back a couple of millennia at least, so I don’t think anyone was going to make such a claim in the face of those. And just what the heck is objective reality? Philosophers talk about such things, but scientists? Scientists are forever devising replacements for our senses to expand our observation capabilities. Why would they be looking for those if our senses were thought to portray “objective reality” all by themselves?

“Ever since Homo sapiens has walked the earth, natural selection has favored perception that hides the truth and guides us toward useful action, shaping our senses to keep us alive and reproducing.” If you take “hides the truth and” out, this is quite correct. But scientists aren’t interested in truth, not even a little bit. And evolution did nothing to hide anything, certainly not “the truth.” Anything that did happen that increased our reproductive success was kept and anything that did not was not. It was not about perfecting one’s senses or hiding the truth or whatever. This is deceptive use of language, making evolution out to be a villain which is “hiding the truth,” the truth of a revealed god, perhaps?

“The real-world implications for this discovery are huge.” No they are not. Don’t be silly. We have known much of this for quite some time. Have you noticed people going crazy in the streets? The stock market in turmoil? (Check that, the stock market is always in turmoil.) Animals retreating into the hills? Babies crying continuously?

People, this is all quite simple. All animals perceive the world around them. This is a requirement for the ability to move. All of these perceptions are limited. Eagles have much better visual acuity than do humans. So effing what? Whatever our visual acuity is, it will not be perfect. Our ability to distinguish different pitches of sound provides us with the ability to communicate vocally. But bats and dolphins hear quite different kinds of sounds. So what? Whatever that ability, it will be limited by the mechanism used to transmit the physical stimulus (compressed waves in the air) into signals our brains can deal with. We cannot hear high pitched sounds and very low pitched sounds, but other animals can. BFD. None are perfect.

And for every sense we have, our brain has to come up with some kind of system to codify them, just as we do socially. (We have an Orange Alert for Southern California! Shoppers we have a Grocery Department Special on Aisle 7!)

There is no real or imagined sensory input system that reveals whatever the heck objective reality is. So, yes, reality is a matter of opinion. We spend a great deal of time interacting with other people and sharing our realities, only to find ourselves perplexed as to how some people just can’t see the truth right in front of their faces. This also is why we have so many people who believe imaginary supernatural beings and events are “real.” If their reality were not subjective, would they still be able to cling to their fantasies?


  1. Well, I have read the book.

    Much of the literature on vision has operated on the theory that what we see is not exactly what is out there but that it is more or less homologous to what is out there.

    Hoffman goes further and argues not only are our perceptions not homologous they probably are nothing like what is out there. He has a whole book Visual Intelligence dealing extensively with visual illusions.


    Comment by James Cross — September 18, 2019 @ 12:15 pm | Reply

    • I probably will not read that book, but I think he might be protesting a bit too much (in the blurb).

      Our eyes, for example, take in light and project it onto a two dimensional surface (the retina) which automatically loses 3-D information which must be deduced from clues (the railroad tracks seem to be getting closer together but I know they are not, so that section of track must be farther away, etc.). The poor design of having the optic nerve leave through the retina leaves a blind spot which we fill in. Our shape recognition brain functions are heavily dependent upon outlines, so they get emphasized over other data, etc. I am sure some brilliant engineer could design a better system but our designer, evolution, settles for functions and workarounds that do the job but are not optimal. I don’t see that as “evolution hiding the truth” as truth is not something we can get through a sensory system. Evolution gave us the brains to figure out the limitations of our sensory system so as to make allowances and corrections for those. Seems fair enough.

      I apologize if I am “preaching to the choir.” Sometimes I write these things out to clarify my own thoughts. (I guess that is why God gave us the Delete button!)

      On Wed, Sep 18, 2019 at 12:15 PM Class Warfare Blog wrote:


      Liked by 1 person

      Comment by Steve Ruis — September 19, 2019 @ 11:34 am | Reply

      • Granted the claim in the title might be a little hyperbolic. The idea is to sell books.

        Your observation about vision is a good example of how our perceptions are rigged-up or hacked. We seldom appreciate that and go through our lives thinking our VR is real. But it makes sense we can do that because just like in any VR the actions we take have consequences in the VR.


        Comment by James Cross — September 20, 2019 @ 6:37 am | Reply

        • Absolutely. There is no harm in acting as if what we sense is what is there. If, however, we want to delve into the fine points, it behooves people to learn a little about how our senses work. (Didn’t know bees had hooves, did you?)

          On Fri, Sep 20, 2019 at 6:37 AM Class Warfare Blog wrote:



          Comment by Steve Ruis — September 20, 2019 @ 9:03 am | Reply

  2. BTW, you can get almost all of his interface theory of perception for free at this link.


    Comment by James Cross — September 18, 2019 @ 12:24 pm | Reply

    • Thanks!

      On Wed, Sep 18, 2019 at 12:24 PM Class Warfare Blog wrote:



      Comment by Steve Ruis — September 19, 2019 @ 11:34 am | Reply

  3. It’s more of a case against perception, isn’t it? 😁


    Comment by The Pink Agendist — September 18, 2019 @ 3:59 pm | Reply

    • Basically the view is that perceptions and actions based on perceptions evolved because of their survival advantage. There is an advantage to shortcuts or hacks because nature can evolve shortcuts more easily and the reaction time for a shortcut usually will be faster. In some cases, the downside of false positives is a lot less than more accurate perception. Humans apparently can pick out snake patterns and forms in brush quite well but what we are seeing likely isn’t the actual snake but an image optimized for quick recognition to get us to run and/or avoid the area. In this case, the downside of a false positive snake is almost nil but the upside of avoiding of a constrictor is life vs death.

      Hoffman carries this idea quite far even to the point of arguing the 3 spatial dimensions and time are likely false perceptions. The actual world may have hundreds of dimensions or may be even dimensionless but we impose the dimensions as a hack for us to operate in the world.

      Liked by 2 people

      Comment by James Cross — September 18, 2019 @ 6:35 pm | Reply

  4. This is long, but quite interesting…Michael Shermer has a terrific podcast on Utube.


    Comment by maryplumbago — September 19, 2019 @ 12:22 pm | Reply

  5. So, if somebody were to see this book as accurate and groundbreaking, their perception, according to the book itself, would probably be false….


    Comment by List of X — September 28, 2019 @ 6:32 am | Reply

    • I think the problem in this case is a fixation on “true and false.” I do not think a perception system can be created that shows only “true” representations of reality (whatever that is). I think we need to learn how our perception systems, aka senses, work and adjust accordingly. For instance, we cannot see far into space with our naked eyes, so we invent telescopes. We cannot see outside of the small range of wavelengths of light our eyes are evolved to interact with, so we invent radio telescopes, infrared telescopes, etc.

      “Move along, this is not the mystery you are looking for.” (Not even a Jedi mind trick.)

      On Sat, Sep 28, 2019 at 6:32 AM Class Warfare Blog wrote:



      Comment by Steve Ruis — September 28, 2019 @ 8:57 am | Reply

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