Chapter 7.                           Part B 

Mathematically, the Bayesian decision situation can be represented if we let Pr(H/B) be the degree to which we trusted the hypothesis before we observed a bit of new evidence,  Pr(E/H&B)  be the degree to which we expected the evidence if, for the sake of argument, we briefly assumed that the hypothesis was true, and Pr(E/B) be the degree to which we expected this evidence to happen based on what we knew before we ever met this hypothesis (using only our old, familiar background models, and not the new hypothesis, in other words).

Note that these terms are not fractions in the normal algebraic sense at all. The term Pr(H/B) is called my “prior expectation” and should be read “my estimate of the probability that the hypothesis is a correct one if I base my estimate just on how well the hypothesis fits together with my whole familiar set of background assumptions about the world.” 

The term Pr(E/H&B) should be read “my estimate of the probability that the evidence will happen if I assume just for the sake of this term that my background assumptions and this new hypothesis are both true”. Finally, the term Pr(E/B) can be read “my estimate of the probability that the evidence (the event that the hypothesis predicts) will occur if I base my estimate only on my ordinary set of background assumptions and do not use the new hypothesis at all”.

The really important symbol in the equation comes now, and it is Pr(H/E&B). It stands for how much I now am inclined to believe that the hypothesis gives a correct picture of reality after I have seen this new bit of evidence, while taking as a given that the evidence is as I saw it - not a trick or illusion of some kind - and that the rest of my background beliefs are still in place.

Thus, the whole probability formula that describes this relationship can now be expressed in the following form:

Pr(H/E&B) =  Pr(E/H&B) x  Pr(H/B)

                      Pr(E/B)  

       Now this formula looks daunting, but it actually says something fairly simple. A new hypothesis that I am thinking about, and trying to understand, seems more and more likely to be correct the more that I keep encountering new evidence that the hypothesis can explain and that I can’t explain using any of the models of reality that I already have in my background stock of ideas. When I set the values of these terms, I will assume, at least for the time being, that the evidence that I saw (E) was as I saw it, not some mistake or trick or delusion, and that the rest of my background ideas/beliefs about reality (B) are valid.

               

        I tend more and more, then, to believe that a hypothesis is a true one the bigger Pr(E/H&B) gets and the smaller Pr(E/B) gets. 

        In other words, I more and more tend to believe that a new way of explaining the world is true, the more it can be used to explain the evidence that I keep encountering in this world, and the less I can explain that evidence if I don’t accept this new hypothesis into my total set of ways of explaining and understanding the world.

Chapter 7       Bayesianism:  A Major Theoretical Criticism And A Response              Part A

The Bayesian way of explaining how we think about, test, and then adopt a new model of reality has been given a number of mathematical formulations. They look complicated, but they really aren’t that hard. I have chosen one of the more intuitive ones below because I intend to use it to discuss the theoretical criticism of Bayesianism which I mentioned in the last chapter.

The Bayesian model of how a human being’s thinking evolves can be broken down into a few basic components. When I, as a typical, modern human, am examining a new way of explaining what I see going on in the world, I am considering a new hypothesis, and as I try to judge just how true – and therefore how useful – a picture of the world this new hypothesis may give me, I look for ways of testing the hypothesis that will tend to show decisively one way or the other whether this new hypothesis and the model of reality that it is based on really work. What I am trying to determine is whether or not this hypothesis will help me to understand, anticipate, and respond effectively to, events in my world.

When I encounter a test situation that fits within the range of events that the hypothesis is supposed to be able to explain and make predictions about, I tend to become more convinced that the hypothesis is a true one if it does indeed enable me to make accurate predictions. (And I tend to be more likely to discard the hypothesis if the predictions that it leads me to make keep failing to be realized.) I am especially more inclined to accept the hypothesis and the model of reality that it is based on, if it enables me to make reliable predictions about the outcomes of these test situations and, if also, in the meantime, all of my other theories and models are silent or inaccurate when it comes to explaining my observations of these same test situations.

It is worth noting again here that this same process can also occur in a whole nation when increasing numbers of citizens become convinced that a new way of doing things is more effective than the status quo practices. "Popular" ideas, the few that really work, last. In other words, both individuals and whole societies really do learn, grow, and change by the Bayesian model. 

In the case of a whole society, the clusters of ideas that an individual sorts through and tries to shape into a larger idea-system become clusters of citizens, forming factions within society, each arguing for the way of thinking that it favors. The leaders of each faction search for reasoning and evidence to support their positions in ways that are closely analogous to the ways in which the various biases in an individual mind struggle to become the idea system that the individual follows. The difference is that the individual usually does not settle very heated internal debates by blinding his right eye with his left hand. (i.e. Each of us, usually, chooses to set aside unresolvable internal disputes rather than letting them make him crazy. Societies, on the other hand, have riots and, sometimes, revolutions.) 

In societies, factions sometimes work out their differences, reach consensus, and move on without violence. But sometimes, of course, as noted above, they seem to have to fight it out. Then violence between factions within society, or violence with the neighboring society that is perceived as being the carrier of the threatening new ideas, settles the matter. But Bayesian calculations are always in play in the minds of the participants, and these same calculations almost always eventually dictate the outcome. One side gives in and learns the new ways. The most extreme alternative, one tribe’s complete and genocidal extermination of the other, is only rarely the final outcome.

But let us now deal with the flaw that is seen - mistakenly, I will argue - by the critics of Bayesianism in the mathematical formula that purports to model the Bayesian decision-making process.

Chapter 6.                               Part F 

The evidence proving that a given, deeply imprinted, old value and the behaviors that it fosters have become counter-productive and outmoded is often not even recognized by the ones who hold and live by that value. Rather, the evidence is recognized by the nation, or even by the whole human race, when those people, their values, and their way of life don't survive as well as their competitors do. Then, they slowly adjust, by modifying some of their ways, if that is possible in the available time, or they, their values, and their ways die out altogether. The El Molo are almost gone. The Canninites, Bo, Anastazi, and Beothuk are gone. Troy and Carthage are gone. None of this is fair. It’s just over.

                                    

                                       Demasduit (one of the last Beothuk) 

In the more gradual adjustments that some societies have managed to achieve, it sometimes also happens that sub-cultures within a society die out without the whole tribe dying out, and thus some values and beliefs in the culture die out while the larger culture itself, after sustaining major trauma and healing, adjusts and goes on.    

          

For example, Hitler and his Nazi cronies ranted until their last hour that their "race" should fight on till they all went down in a sea of blood because they had shown in the most vital of arenas, namely war, that they were weaker than the Russians. He sincerely believed his Nazi philosophy. In the same era, the Japanese cabinet and High Command contained members who were adamant in arguing that the Japanese people should fight on, even in the face of hopeless odds. To do anything other than to fight on was literally inconceivable to these men. (Yukio Mishima's case was a curious last gasp of Japanese imperialism.) (5.) Fortunately, people who could face reality, learn, adapt, and then thrive eventually prevailed, in both Germany and Japan.

                               

                                                     Yukio Mishima 

For centuries, human "nature" has not enabled humans to assess value systems by our cognitive abilities, and then adopt or drop these systems in that vacillating cognitive way. In our tribalism, we are built to see the moral values and the mores that we grew up with as being “right” and “good”. Humans are thus designed by evolution to fight to the death to defend and promulgate what we in the West call our “way of life”. When the ways of life of two different cultures come into confrontation, for whatever set of reasons, the war that often follows then decides which is the more vigorous way of life. The stronger society/culture goes on and expands; the weaker one fades and is absorbed. Or dies out. By this mechanism of cultural evolution, the total human culture-meme pool, for eons, has grown strong. For eons, this was good for the culture-meme pool, but bad for those caught up in the confrontations.   

A culture is just the software of a nation. A culture evolves and survives or else falls behind and dies in ways that are analogous to the ways in which a genome survives or dies. If a culture-program gets good practical results over generations, its carriers multiply; if not, they don't, and then they and it fade out of our species’ total culture pool. What was sad but true for centuries was that a society's fitness to survive was sometimes tested by famine or epidemic disease or natural disaster, but more often it was tested by war with one of its neighbors. For centuries, when a tribe, guided by its culture, was no longer vigorous enough to hold its territory against invasions by neighboring tribes, it fought and lost. Its men were killed, its women and children were carried off by the enemy; its way of life dwindled and was absorbed, or in some cases, vanished entirely. Thus Joshua smote Hazor, the ancient Greeks crushed Troy, the Romans, Carthage. Out of existence. The examples could go on. 

 

                                 ruins of Carthage in modern Tunisia 

  

   So was Hitler right? Is war inevitable, even desirable? It depends. The question that we are left with is whether we will ever rise above our present, mainly war-driven system of cultural evolution. By reason or suffering or both, we are going to have to arrive at a new process for evolving culturally, which means continually adopting, in a timely way, constantly updated, more efficient values and the behavior patterns that are fostered by, and, therefore attached to, these values.

Changes in our circumstances always come. Some of them we even cause. We can cushion our way of life against them for a while, but over time, reality demands that we either evolve or die out.

But for now, I will leave the war digression and the socio-cultural mechanism of human evolution to be more thoroughly discussed in later chapters.

For now then, let’s settle for saying that this point that Bayesianism’s critics make about the way in which some areas of human behavior do not seem to be based on Bayesian types of calculations only seems at first to be an apt criticism. If we study the matter more deeply, we see that there are reasons for our apparently un-Bayesian attachments to some of our most counter-productive values and morés. They are just crude, upsetting, warmongering reasons -- design flaws that we are going to have to deal with because they have long since fallen out of touch with the physical reality that surrounds us (a physical reality that, in large part, we have created) and with the dilemma in which we find ourselves. "Mankind must put an end to war or war will put an end to mankind." (John Kennedy) (6.)

                             John F. Kennedy, 35th president of the U.S. 

Most importantly, for the purposes of this book, we can see that the Bayesian model of human thinking still holds. Deeply held beliefs, values, and morés do get changed – sometimes even in whole nations – by the Bayesian mechanism. We do get rid of old beliefs and adopt new ones when the old ones are no longer enabling us to handle the physical and social realities that we are seeing before us. If the father and mother can’t drop ineffectual old beliefs and adopt new ones, then the son and daughter must, or else the tribe dies out altogether. In other words, we humans do learn, change, and adapt, both as individuals and as whole nations.

Individuals can learn and change on most ordinary, practical matters. However, by and large, they won’t willingly alter their deepest, most general, core beliefs - the ones called “moral values”. These get changed only when a whole nation gets taught a very large, painful lesson and then re-configures. And once in a long while, a really stubborn culture dies out altogether. 

   

We will have more to say on these matters in later chapters. The first big criticism of Bayesianism has been dealt with. The Bayesian model, when it is applied at the tribal level of human behavior, can fully account for the apparently un-Bayesian behaviors of individuals. We now must move on to the second big criticism of Bayesianism, the theoretical one.

And perhaps this is the point at which I should also say that the next chapter is fairly technical, and it isn’t essential to my case. If you want to skip a chapter, my next chapter is one that you can skip and still not lose the train of thought leading to the conclusion of the whole argument.

Notes 

1.http://www.academia.edu/4029955/Degenaar2013_Through_the_Inverting_Glass

2. Kuhn, Thomas; "The Structure of Scientific Revolutions"; University of Chicago; 1996

3. http://www.constitution.org/jsm/women.htm

4. http://en.wikiquote.org/wiki/Alfred_North_Whitehead

5. http://en.wikipedia.org/wiki/Yukio_Mishima

6. www.jfklibrary.org/Asset-Viewer/DOPIN64xJUGRKgdHJ9NfgQ.aspx

Chapter 6.                          Part E 

It is also worthwhile to say the obvious here, however politically incorrect it may be. All of our obsolete but obstinate beliefs, moral values, morés, and behavior patterns did serve useful ends and purposes at one time. For example, in some, not all, early societies, women were programmed to be submissive, first to their fathers and brothers, then to their husbands. The majority of the men in such societies were far more likely, in purely probabilistic terms, to help to nurture the children of their socially-sanctioned marriages because they were confident that the children they had with these submissive women, and that they were being asked to help to nurture, were theirs. Biologically theirs.

Raising kids is hard work. In early societies, if both parents were committed to the task, the odds were simply better that those kids would grow up, marry, have kids of their own, and go on to program into those kids the same values and roles that the parents themselves had been raised to believe in. Other, non-patriarchal societies taught other roles for men and women and other designs for the family, but they simply weren’t as prolific over the long haul. Patriarchy isn’t fair. But it makes populations.

                        

                         Magazine image of the American family (1950's) 

“Traditional” beliefs about male and female roles didn’t work to make people happy. But they did give some tribes numbers and, thus, power. They are obsolete today partly because child nurturing has been taken over to a fair degree by the state (schools), partly because no society in a post-industrial, knowledge-driven economy can afford to put half of its human resources into homes for the stagnant, bored, and dejected, and partly because there are too many humans on this planet now. Population growth is no longer a keenly sought goal because it no longer brings a tribe/nation power. But more on this matter later. It is enough here to say that all of our traditional values, mores, roles, etc. once did serve useful purposes. Many of them clearly don’t anymore, even though it is like pulling back molars without anesthetic to get the reactionaries among us to admit that many of their cherished “good, old ways” are just in the way in today’s world.   

       

Thus, in all areas of their lives, even those that they think of as “sacred”, “traditional”, and “timeless”, humans do change their beliefs, values, and patterns of behavior in the manner suggested by Bayesianism. We do always adopt a new view of reality and the human place in it if that new view is more coherent with the facts that we are observing and experiencing, and it gets us better lives. We’ve come a long way in the West in our treatment of women and minorities. Our justice systems aren't race or gender neutral yet, but they're much better than they were even fifty years ago.

The larger point, however, can be reiterated. For deep social change, we do undergo the Bayesian decision process, but only in the most final of senses. Sometimes what has to learn to adopt new beliefs, values, and mores isn’t the individual; sometimes it is a whole community or even nation.

Chapter 6.            Part D 

The mechanism of cultural evolution being described here is profoundly disturbing; it deserves some digression. What is being said here is that humans often do behave in ways that seem irrational by purely Bayesian standards. Even in our time, some adults still spank kids. Some men still bully women. Some states still execute their worst criminals. Research, as well as careful observation and analysis of these and many other patterns of behavior, suggests strongly that they don’t work; these behaviors do not achieve the results at which they aim. In fact, they reduce the chances that we will achieve those results. These behaviors and the beliefs underlying them are exactly what is meant by the term “counterproductive”. Therefore, we must ask an acute question: “Why do we do them?” Which is to say: “Why do we, as rational humans who usually operate under a rational, Bayesian belief-building system, hold on so obstinately, in a few areas of our lives, to beliefs that cause us to act in utterly irrational ways?”

                

                                 Electric chair (used to execute criminals) 

The reply is that we do so because our culture's most profound programming institutions –  the family, the schools, the media, etc. – continue to indoctrinate us with these values so deeply that once we are adults, we refuse to examine them. Instead, our programming directs us to bristle, and then defend our "good old ways", violently if need be. When deep moral beliefs, and the morés that they foster, begin, by one mechanism or another, to die out, some folk are even willing to die out with them. If the ensuing lessons are harsh enough, and if there is a reasonable amount of available time, sometimes the larger society learns, expels the reactionaries, and then adapts. But the process of deep social change is always difficult and fraught with hazards. "The major advances in civilization are processes which all but wreck the societies in which they occur." (A.N. Whitehead) (4.)

                                                   

                                               Alfred N. Whitehead 

Chapter 6.                 Part C 

It is also important to state here that, for most new paradigms and practices, the tests applied to them over the days or decades only confirm that the old way is still better. Most new ideas are tested and found to be less effective than the established ones. Our forefathers were striving hard, and they were pretty smart. 

But the more crucial insight is the one that comes next. Sometimes, if a new paradigm touches on a tribe’s most sensitive central beliefs, then the Bayesian calculations about what individuals and their society are going to do next break down. When a new idea challenges those sensitive central beliefs, then most tribes continue to adhere to the old beliefs. The larger question here is whether the Bayesian model of human thinking, when it is taken up to the level of human social evolution, can account for these apparently un-Bayesian behaviors. 

     

Many of our most deeply held beliefs are ones that have to do with those areas of our lives that govern our interactions with other humans – family members, neighbors, co-workers, fellow-citizens, etc. These are the areas of our lives which we have long seen, and mostly still see, as being guided not by reason but by “moral beliefs”, beliefs derived in ways that are different from our beliefs about the physical world. In anthropological terms, these are the beliefs that enable the members of the tribe to live together, interact, work in teams, and get along.

In our time, the exploitation of women, the execution of murderers, and the other anomalies described in earlier paragraphs are merely consequences of the fact that in spite of our worries about the failures of our moral code in the last hundred years, much of that code lingers on. In many aspects of our lives, we are still drifting with the ways that were familiar, even though our confidence in those ways is eroding around us. We don’t know what else to do. In the meantime, these traditional ways are so deeply ingrained and familiar as to seem, for many people, natural, even automatic, in spite of evidence to the contrary.

What we are dealing with when we study the deepest and most profound of these "traditional" behaviors and beliefs are those beliefs that are very deeply programmed into every child by all of the tribe’s adult members. These beliefs aren’t subject to the Bayesian models and laws which usually govern the learning processes of the individual human. In fact, they are almost always viewed by the individual as the most important parts of not just his culture, but himself. They are guarded in the psyche by layers of emotional associations that elicit anger and fear when disturbed. They are the beliefs and practices that your parents and your teachers, storytellers, and leaders enjoined you to hang on to at all cost. For most people in most societies, these beliefs and the morés that they elicit are viewed as being simply “normal” and “human”.

    

Our moral meta-belief, that is to say our belief about our moral beliefs, for centuries, was that they were set down by God and, therefore, were universal and eternal. When we made such a distinction, we were in effect, placing our moral beliefs in a separate category from the rest, one meant to guarantee their inviolability.

                                                        

                      

                                                  John Stuart Mill 

But are our moral beliefs really different in some fundamental way from our beliefs in areas like Science, Athletics, Automotive Mechanics, Farming, or Cooking? The answer is ‘Yes and no’. Better farming practices and medical procedures we are eager to learn, and who doesn’t want to win at the track meet? However, in their attitudes about the executing of our worst criminals or the exploitation and subjugation of women, many in our society are more reluctant to change. Historical evidence shows societies can change in these sensitive areas of their lives, but only grudgingly. (John Stuart Mill discusses the obstinacy of old ways of thinking about women, for example, in the introduction to "The Subjection of Women".) (3.)

  

These beliefs which humans hold most deeply, the ones that most obstinately resist change in the belief set shared by a whole nation, are ones that are nearly impossible to amend by rational persuasion of individuals. They only get eradicated at all if they are eradicated from a whole nation when evidence shows glaringly that they no longer work. They fail to provide effective real-world guidelines by which the humans who hold them can make choices, act, and live their lives. They fail so totally in this role that the people who hold the old values begin to die out. They die young, or fail to reproduce, or fail to program their values into their young, or the whole tribe may even be overrun. By one of these mechanisms, a tribe’s whole culture and values system can finally die out. The genes of the tribe may go on in kids born from the merging of two tribes – the victors and the vanquished – but one tribe’s set of beliefs, values, and morés, i.e. its culture, becomes a footnote in history. 

Chapter 6.             Part B 

Now at this point in the discussion, opponents of Bayesianism begin to marshall their forces. These critics of Bayesianism give several varied reasons for continuing to disagree with the Bayesian model, but I want to deal with just two, two of the most telling, one for practical, evidence-based reasons and the other, in the next chapter, for purely theoretical reasons.

In the first place, say the critics, Bayesianism simply can’t be an accurate model of how human beings think because humans violate Bayesian principles of rationality every day. Every day, we commit acts that are at odds with what both reasoning and experience have shown us is rational. Some societies still execute criminals. Men continue to bully and exploit women. Adults spank children. We do these things even when both formal research everyday experience indicate that such behavior is counter-productive.

We fear people who look different than we do on no other grounds than that they look different than we do. We shun them even when we have evidence which shows that there are many trustworthy individuals in that other group and many untrustworthy ones in the group of people who look like us.

Over and over, we act in ways that are illogical by Bayesian standards. We stake the best of our human and material resources on ways of behaving that both reasoning and evidence say are not likely to work. Can Bayesianism account for these glaring bits of evidence that are inconsistent with its model of human thinking?

The answer to this critique is disturbing. The problem is not that the Bayesian model doesn't work as an explanation of human behavior and thinking. The problem is rather that the Bayesian model of human thinking and the behaviors driven by that thinking works too well. The irrational behaviors which individual humans engage in are not proof of Bayesianism's inadequacy, but rather of how it applies not only to the thinking, learning, and behavior of individuals, but sometimes moves up a level to the thinking, learning, and behavior of whole communities and even whole nations.

Societies evolve and change because, in every society, there are some people who are naturally curious. These curious people constantly imagine and test new ideas and new ways of doing things – getting food, raising kids, fighting off invaders, healing the sick – any of the things that the society has to do in order to carry on. It is also often the case that other sub-groups in society view any new idea or way of doing things as threatening to their most deeply held beliefs. If the adherents of the new idea keep demonstrating that their idea works, and thus, that the more intransigent group’s old ways are obsolete, and if that intransigent sub-group steadfastly refuses to re-write its belief system, then the larger society will, usually, marginalize the less effectual members and their system of ideas. In this way, a society mirrors what an individual does when he/she finds a better way of growing onions or teaching kids or easing Grandpa's arthritic pain. We adapt - as individuals, but more profoundly, as societies - to new lands and markets and to cars, televisions, vaccinations, email, etc. Farmers and cooks and teachers who cling to methods that don't work very well are simply passed by, eventually even by their own grandchildren.  

  

But then there are the more disturbing cases, the ones that make me say "usually" above. Sometimes large minorities or even majorities of citizens hang on to obsolete concepts and ways. 

The Bayesian model of human thinking works well, most of the time, to explain how individuals form and evolve their basic idea systems. Most of the time, it also can explain how a whole community, tribe, or nation can grow and change its sets of nation-wide beliefs, thinking styles, and customs and practices. But can it account for the times when majorities in the community do not embrace new ways even when the Bayesian calculations and the evidence show the ideas to be sound? In short, can the Bayesian model explain the darker sides of tribalism?

          

                                          Nazi party rallies: Tribalism at its worst 

  

As we saw in our last chapter, for the most part, individuals become willing to drop a set of ideas that seem to be losing their effectiveness when they also encounter a new set of ideas that looks more promising. They embrace the new ideas that perform well, i.e. that guide the individual well, through the hazards in real life. Similarly, at the tribal level, whole societies usually drop paradigms, and the ways of thinking and living based on those paradigms, when the citizens keep seeing that the old ideas are no longer working and that there is a set of new ideas that is getting better results. Sometimes, on the level of changes that sweep across a whole society, this mechanism even means societies marginalize or ostracize sub-cultures that refuse to let go of the old ways.  

The point is that when a new sub-culture with new beliefs and ways keeps getting good results, and the old sub-culture keeps proving ineffectual by comparison, the majority usually do make the switch to the new way …of chipping flint, or growing corn, or spearing fish, or making arrows, or weaving cloth, or building ships, or forging gun barrels, or dispersing capital to the enterprises with the best growth potential, or connecting a computer to the internet.

Chapter 6       The First Attack On Bayesianism And How It Is Answered          Part A

The idea behind Bayesianism is straightforward enough to be grasped by nearly all adults in any land. But the idea of radical Bayesianism escapes us. All that you do, mentally, fits inside the Bayesian model, but it is very human to dread such a view of oneself and to slip into thinking that radical Bayesianism must be wrong. We want desperately to believe that at least a few of our core ideas are unshakeable. Too often, unfortunately, people do think that they have found one. But to a true Bayesian, the one truth that he believes is probably absolute is the one that says there are no absolute truths.

An idea is a mental tool that enables you to sort, and respond to, sensory experiences – single ones or whole categories of them. When you find an idea that works, you keep it. What can confuse and confound this whole picture is the way that, in the case of some of your most deeply held ideas, you didn’t personally find them. They came in a trial and error way to some of your ancestors, who found the ideas useful and then did their best to program them into their progeny, etc., and thus they were passed down the generations to your parents, who then programmed them into you.

Every new idea that you acquire gets installed as part of your mental equipment, after careful Bayesian observations and calculations, either by the process of your own noticing, speculating, and testing, or by your family and your tribe programming you with the idea because the tribe’s early leaders acquired that idea by the first process. Consciousness and even sanity are constantly evolving for all humans, all of the time. We keep re-writing our concept sets, from complex ideas like "justice" and "love" to basic ideas like "up" and "down" and even to what I mean by "I". (Individual minds can indeed be made to re-program their notions of “up” and “down”.) (1.) The barest “you” that you are is a dynamic, self-referencing system that is constantly checking your sense perceptions against your ideas about what reality should be and then updating and re-writing itself all of the time.  

And a short side note is in order here. There are also a few commonly used, species-wide ideas, or proto-ideas, that you don't "acquire" by either of the above methods because these ideas are hard-wired into you at birth. These are not programmed into a human by her tribe nor by her own life experiences so they don't fit into either of the categories just described. But they do fit inside the modern empiricist view of what knowledge is simply because in the modern empiricist view, with the models it has gained from Biological Sciences, especially Genetics, these built-in ideas are seen as genetically-acquired anatomical traits and, thus, as subjects for study by geneticists or neurophysiologists. In short, scientists can go looking for them right in the human brain, and they do.

For example, some basic ideas of language are built into all normal humans, but the genes that cause the developing fetus to build the language centers into its developing brain are still being identified. In addition, the structures and functions of these brain areas, once they're built, are only poorly understood. In our present discussion, however, these questions can be passed by. They are biological rather than ideological in nature and, therefore, outside of our present scope. These genes and the brain structures that are built from gene-coded information might someday even be manipulated, either by genetic engineering or some kinds of behavior modifications involving operant conditioning, surgery, drugs, or other technologies we cannot now even imagine.

But whether such actions will be judged right or wrong, and so will be permitted in the normal institutions of our society, will depend on our moral values. These, as we have already seen, are going to need something more at their core than what is offered by Empiricism. As its own moral guide, Empiricism has proved neither sound in theory nor effective in practice. The evidence of human history strongly suggests that Science, at least so far, can't be its own moral guide. This line of thought returns us to our task – discussion of moralities and their sources – and so back to Bayesianism.

So let me reiterate: we are nearly all, nearly all of the time, Bayesians. When an old idea no longer works, we seek, by Bayesian ways, to find a better idea.

          

This Bayesian model of how we think is so radical that at first it eludes us. The idea that I am adjusting my whole mindset all of the time, and that no parts of it, not even my deepest ideas of who I am or what reality is, are ever fully established or reliable is disturbing, to say the least. But this view is the one I arrive at when I look back over the changes that I have undergone in my own life. The Bayesian model of how a “self” is formed, and how it evolves as the organism ages, fits the set of memories that I call “myself” exactly.

            

                                                          Thomas Kuhn

   

Thomas Kuhn was the most famous of the philosophers who have examined the processes by which people adopt a new theory, model, or way of knowing. (2.) His studies focused only on how scientists adopt a new model, but his conclusions can be applied to all human thinking. His most famous book proposes that all of our ways of knowing, even our most cherished ones, are tentative and arbitrary. Under his model of how human knowledge grows, humans advance from an obsolete idea or model to a newer, more comprehensive one by "paradigm shifts", i.e. leaps and starts, rather than in a steady march of gradually growing enlightenment. You "get", and then start to think under, a new model for organizing your thoughts by a kind of conversion experience, not by a gradual process of persuasion and growing understanding. 

It is all very disconcerting. Caution and vigilance seem to be the only rational attitudes to take under such a view of the universe and the human place in it. 

  

Of course, to many people, the idea that all of the mind's systems and systems for organizing systems, and perhaps even its overriding operating system, its sanity, are tentative and are subject to constant revision seems disturbing; some prefer to label it “absurd”. But then again, cognitive dissonance theory would lead us to predict that humans would quickly dismiss such a scary picture of themselves. We don't like to see ourselves as lacking in any unshakable principles or beliefs, changing and evolving from stage to stage in life. But evidence and experience suggest that we are indeed almost completely lacking in such fixed principles or beliefs, and we do nearly always evolve personally in those ways. (Why I say "nearly" always will become clear shortly.)