The above image links to the original video, or just click here. As always: a wonderfully insightful talk. This is not a summary of the talk but rather my two favourite quotes (passages?). The talk contains important material on what an AGI must be and why we must not treat them differently to any other "race" of people. There is a wonderful part about how the feared existentially deadly "black balls" in urns can be turned into white balls - given the existence of people and when they create the requisite knowledge. The black balls are supposed to be problems we cannot solve in time - as though our inventions are random things we pluck from the unknown and cannot learn more about over time, let alone in time. I leave those matters aside for now.

Emphasis (in bold and/or underlined) is my own.

Quote 1 (From 13 mins 30 secs)
 
“Once we have a universal constructor, all construction, all repetitive labour, will be replaced by writing computer programs to control the universal constructor. And wealth will consist of our library of programs. The universal constructor can be programmed to self reproduce, so once you have one you soon have 2^n of them and it can be programmed to perform self maintenance too, all from scratch: starting with mining the raw materials – perhaps from the asteroid belt using solar energy or whatever. The program may be hard to write, but once it’s written and if you own the rights to those asteroids – you can sit back and watch your 2^n Teslas roll in, with zero additional effort. And no, we are not going to have a universal constructor apocalypse and be converted to grey goo. A universal constructor is just an appliance – it can’t think – it doesn’t know that its present job is to make 2^n Teslas and it doesn’t want anything. Unless of course you put an AGI program into it. Then it does become indeed potentially dangerous without limit. But that’s for the same reason that you are. Each of you is precisely one of those universal constructors endowed with an AGI program. Or I should say GI? It makes no difference.”
 
Quote 2 at 17 mins exactly (this is after describing two kinds of dangers most people are concerned about - known dangers like deadly viruses without cures, for example).
 
“The third category of dangers are the ones to which most efforts should be devoted and yet they are the ones that are currently least feared because they are ones that are not yet known. Like in 1900 no one knew that smoking was dangerous. By the time the knowledge…that it was dangerous had been created decades later, cigarettes had killed hundreds of millions of people. Again – if that had been an existential danger, whom could we sue? So: how can we create the knowledge to protect ourselves from existential or near existential dangers that we do not know? How to address the risk that by the time we do know, we won’t have time enough to create the requisite knowledge? The answer is: by creating general purpose knowledge – deep and fundamental knowledge – as fast as possible – the more we know of the world, the faster we can create new knowledge about novel aspects of it that turn up and become urgent. This is important – I don’t think it’s widely appreciated – the survival of our species depends absolutely on progress in fundamental research in science and on the speed at which we make progress there. And here the key thing in the medium term is understanding the theory of universal constructors, so that we shall know in principle – in theory – how to program them to produce, say, a billion space ships in a hurry customised to deflect an approaching shard of neutronium* or 10 billion doses of a new vaccine in a hurry against a sudden and deadly disease. So that’s how we deal with the third category of the unknown. By rapid progress of every kind: especially the fundamental. The fourth category is at once even more dangerous and yet, in a sense less worrisome because we already have the knowledge -at least the theoretical knowledge to deal with it. This fourth category is not the unknown – the unknowable. It’s a bit paradoxical that the unknowable is less dangerous than the merely unknown but that’s because the only thing that is unknowable is the content of explanatory knowledge that hasn’t been created yet and so the only truly dangerous things in that sense in the universe are entities that create explanatory knowledge - us - people – AGIs too are people. Now, the knowledge of how to prevent people from being dangerous is very counter intuitive – it took our species many millennia to create it but now we do have that knowledge. The only way to prevent people from being dangerous is to make them free. Specifically it is the knowledge of liberal values, individual rights, the open society, the Enlightenment and so on. In such societies, the overwhelming majority of people regardless of their hardware characteristics – are decent. Perhaps there will always be individuals who aren’t: enemies of civilisation, people who take it into their head to program a universal constructor to convert everything in sight into paperclips and they may devote their creativity to doing that – but the great majority will devote – that is the great majority of the population of such a society will devote some of their creativity to thwarting that and they will win provided they keep creating knowledge fast in order to stay ahead of the bad guys." 
 
*Note: neutronium is a kind of matter out of which neutron stars are made. It is composed entirely of neutrons and is thus exceedingly dense and would, for example, destroy a planet made of normal matter by causing severe gravitational effects on the planet (by, say, converting all of the planet itself into neutronium if it came in contact with the planet). 
 
 
 

On a recent “Making Sense” podcast with Sam Harris, Dr. Nicolas Christakis called for the closing of schools across the United States. Dr. Christakis list of qualifications is extensive: a sociologist and physician, the director of the “Human Nature” lab researching the ways in which (and presumably extent to which) evolution drives human behavior. He has an M.D and a PhD (in sociology). Crucially, he has worked in epidemiology. At a time such as the corona crisis of 2020, he must have much to offer so if he says “close the schools” we should listen: https://www.sciencemag.org/news/2020/03/does-closing-schools-slow-spread-novel-coronavirus
 
On another recent “The Joe Rogan” podcast, Dr Michael Osterholm called for schools NOT to be closed. See that podcast or here: https://www.washingtonpost.com/education/2020/03/09/is-it-really-good-idea-close-schools-fight-coronavirus/ Dr Osterholm likewise, among his considerable qualifications, lists “epidemiologist”. Unlike Dr. Christakis, however, Dr. Osterholm lists little else among his interests. He is a specialist, not a generalist. He is, crucially, Director of the Centre for Infectious Disease Research and Policy at the University of Minnesota. His life’s work seems to be devoted to: infectious disease epidemics and is a consultant to the World Health Organisation on this.
 
Dr Amesh Adalja has been more prominent in the media than almost any other expert on COVID-19. He has appeared on The Yaron Brook Show, The Rubin Report, Making Sense, Fox News, CNN and many more besides. He consults with John Hopkins University and has devoted his life to pandemics and biosecurity. He is, again, a very narrow specialist. He has advised against closing schools in a somewhat weaker sense than Dr Osterholm: https://www.livescience.com/should-schools-close-for-coronavirus.html(Other experts at that link agree with the stronger stance of Osterholm)
 
In Australia, Dr. Norman Swan advises the Australian Broadcasting Corporation and has been prominent in the media. He is a physician and journalist who has appeared on a number of popular television programs including “The Biggest Loser” measuring contestants’ “bio age” and comparing it to their “calendar age”. He is across many areas of medicine. He is a generalist. He has repeatedly called on the government to “close the schools” and does not vacillate about it: https://www.abc.net.au/news/2020-03-15/dr-norman-swan-recommends-proactive-national-lockdown/12057956 or here: https://au.news.yahoo.com/health-expert-blasts-government-for-keeping-schools-open-093418822.html
 
The “close the schools argument” seems like common sense. After all: kept in a confined space, won’t a single infected student infect all the others? Wouldn’t it be safer to keep them home? “Why don’t they just” questions are aplenty in these times. So "Why don't they just" close the schools?
 
The argument against closing the schools is harder to make. 

1. If the schools are closed children, who may be infected but show few symptoms, are now, possibly, on the streets. Especially if they are teenagers. Not all parents can “keep their kids inside”. It’s a simple fact, the reality – some number of young people will be at the shops, walking around in the community. They will, by and large, be fine. But the elderly that may cross their paths? The number of severe cases and deaths may increase.
2. Young children need to be cared for. Who will care for them if not the school teachers? Doctors, nurses, ambulance officers, first responders, pharmacists, other hospital workers, medical receptionists, supermarket workers, etc etc may now be forced to stay home to care for their children.

 
It is no sin to be a generalist. I call myself one. And in truth there is no “pure specialist”. But it does take all sorts and some people are far more specialized than others and this is never more true than in medicine. I have no expertise whatsoever in epidemiology (nor indeed any kind of medicine) but if I can, perhaps, claim some modest expertise in anything at all, it might be expertise in experts. I make this claim having spent much time speaking with geologists and geophysicists, astronomers, cosmologist and astrophysicists, chemists and philosophers, theoretical physicists and experimental physicists, medicos of a couple of kinds, lawyers of other kinds, engineers and so on. And I’ve noticed over time certain kinds of blind spots as well as astounding levels of depth. There are some experts, among them a very good friend of mine and he won’t mind my saying – a doctor of exceedingly specialized skill that there are perhaps few in the world who can do what he does – and  who is so very careful to say when he is out of his depth on areas of medicine outside his narrow area. In the area he is an expert, he will speak with confidence and clear sighted knowledge. He seems to know the danger of making medical pronouncements about things that he covered once long ago in lectures at university or perhaps as a general surgical registrar. He simply recognizes he may not be “up to date” with the latest on whatever medical trouble his friends decide to trouble him with on any particular day. His day to day work is about particular organs and particular troubles and while no area of medicine is utterly disconnected from another, he knows there are others out there to defer to when the organ, mere centimeters away, isn’t the one he is known for treating.
 
But he is one kind of expert. There are others, and the medical community is not immune to this, where they feel obliged to make public policy pronouncements when the airwaves are already thick with opinions from actual highly specialized experts. Now should such non-specialist “experts” be shut down? Of course not. But it makes things very difficult for the populace and then for actual authorities (the government) to explain clearly the best policy given the best information. It does not take long, in my experience, for astronomers as a group, to be very willing to give all kinds of advice (and it’s usually always the same) when it comes to economics, public policy, climate policy, university administration and so on. There can be a kind of group think among these experts when it comes to areas outside their narrow field of day-to-day work. And, seemingly, the more specialized they become, the more their other opinions tend to conform to the “man-on-the-street” view. That’s not always a bad thing, but perhaps there is a kind of “creativity limit” where they have exhausted their creative thinking for the day whilst at work and when it comes to other matters they fall back onto more prominent memes circulating among their colleagues. It can certainly make the work day easier and socializing with peers less fraught with friction if ones other ideas conform. There are sociological forces at play, of course. But this phenomenon rarely has any serious effects – but in a time of crisis it may be deadly.
 
The word “expert” is a sliding scale. I trust none of them. But then I have taken on Fox Mulder’s maxim “trust no one” to the core. An expert is someone whom I know (fallibly, as always) has gone though experiences and gained the knowledge via a process of error correction through encounters with reality in the narrow domain within which they call themselves an expert. People like Dr Osterholm and Dr Adalja are the real deal. They are actual infectious disease experts who have worked on outbreaks like SARS-1, MERS and Ebola and tested their theories in the field with WHO and the CDC and so on. They have not merely read the literature or know the theory or kept up to date with the latest texts. They have been actively involved in situations before that are the closest thing to what we face now - at the coal face on these kinds of things. The average M.D, “General Practioner” or even PhD in epidemiology or (especially!) PhD in Mathematical Modelling of Epidemics are not the primary people for government (and media, mind you) to be consulted. Not in the first instance. Secondary people: sure. Helpful in some general sense to critique the primary critiques. But they should seek to clarify not add to the noise and at a time like this, not publicly “think on their feet”. And they should be challenged whenever their pronouncements diverge from that of the primary experts. At best the secondary people should act as knowledgeable conduits of the primary people. If they think they have better ideas: wonderful. They should not be backward in coming forward. But they should likewise have first considered what those primary experts have said. The secondary people should have gone through a careful process of error correction alone, or with their close circle of collegues before going public with some kind of advise to government and others with things like “close the schools” when the top tier specialist people are saying otherwise.
 
Not all people called experts are expert in the specific thing in question. Not all are highly specialized and have devoted their life to, essentially, one thing and had it tested in reality and not merely in some theoretical model. And no expert is an “authority” which is to say: none should ever have the power to shut down debate or direct people against their will. No one should ever do that.
 
However, in a democracy, we have elected officials – politicians – who we have decided can exercise such a power in a crisis. This power should never be delegated and should be used only in extremis. We are not yet “in extremis”. Times are urgent and the word “crisis” is apt. But this is no time to leave behind a sensible concern about which people we can best assume have the knowledge to guide us through.
 
It is rather like we are all on an Airbus A-380 and the announcement comes over the PA system from the chief steward “This is an emergency. There is a fire in an engine and (by remarkable coincidence) the 4 pilots have all fallen gravely ill. We must make an emergency landing. Are there any pilots on board?”
 
5 people step forward to help. 
 
The first is a mathematician who has flown 10,000 hours on an A-380 flight simulator.
 
The second is a light aircraft pilot with 5000 hours experience in a Cessna.
 
The third is a Learjet pilot with 8000 hours experience.
 
The fourth (you can see where I am going with this) is an A-320 captain who is learning to fly the A-380 and has clocked up 1000 hours.
 
And the fifth is Captain Richard Champion de Crespigny - a 15000+ hours experience A-380 Qantas pilot being shuttled back to his home airport and who successfully landed QF-32 when one of the engines caught fire in 2010.
 
It is a wonderful thing the passengers are so fortunate that day to have such a wealth of people to advise them. But though experts according to some broad definition of the word, they are not all "equal" by any means. There is clearly a “best person for the job”.
 
Without the fifth person, I would happily take the advice of number 4. But given the fifth person, and given I know nothing about how to fly a jet of any kind, if there is a dispute between number 5 and any of the others (or even all of the others) I will defer to number 5. Even better if I can understand the debate and 5 sounds reasonable. This is no matter of consensus because the 400 passengers on board may well be serious adherents of the religion of the Spaghetti monster and may vote to turn off the engines and attempt a safe glide into the holy Spaghetti pond.
 
And we need not “obey” the expert here as an authority. Upon safely landing, should our number 5 A-380 Captain then proclaim, upon the tarmac, to indefinately remain on board and wait patiently for the fire brigade as flames began to lick at the windows, I would disobey and help others seek to open the emergency escape for I know enough about aircraft and fuel tanks and fires to know that time is of the essence. I need no "expert" for that kind of thing. There are good reasons to defy an expert (see the actions of the Captain of the South Korean tragedy of the "Sewol ferry" for more on that kind of thing.) Experts can be wrong just like the rest of us but unlike the rest of us are more able to reliably and routinely convey to the rest of us the best available knowledge at any given time. They are not there as inerrant authorities and they should not be expected never to err. That too is a hazard of the “authority” moniker. It means that if the “authoritative expert” makes an error – as surely they will like the rest of us – they should not be blamed unless they have done less than their best. For their best really will be THE best at the given time. That’s what it means to be an expert. They too can fail. 
 
So should we close the schools or not? The striking thing about the split among the experts is that the more specialized in infectious disease outbreaks, it seems the more likely the expert is to advise “no” with caveats and a seeming willingness to change if new evidence is found. But with the generalists: the trend seems to be to advise “close them now” with few caveats. But those generalists risk little because in general they aren’t advising those making those calls. 
 
But we should be there to back them to try again, and again, because at times like this, that’s our best bet.

I was driven to this post by running out of toilet paper and being unable to find any at supermarkets near my house so walked in the rain to the next suburb over to only have to push past people filling whole trolleys with packets of 9 double length rolls as shelf stackers restocked…
 
Have an opinion on the severity of this virus after listening to an expert. Like this guy. He is a scientist who specializes in viruses like this and advises the US government on outbreaks like this.

https://www.youtube.com/watch?v=ZhYcbo7rqEQ
 
I think everyone who wants to venture strong opinions on this virus - including having strong opinions on whether to stockpile things - should either be an expert or watch someone who is, like this guy. But if you cannot do that much, here are some takeaways:
 
The death rate for Corona (COVID-19) way way less than 1%.

Over 80% of cases are mild…many people won’t even realize their 2-day long sniffle was corona-19.

Its R0 value (how contagious it is = how many people an infected person will typically infect) is relatively low at 2.0 to 2.4. Measles, for example, has an R0 = 15.
 
Politicians shouldn’t comment on things they have no idea about. Eg: when Bernie Sanders criticized a pharmaceutical company some time ago, so they stopped working on a vaccine for a related virus due to all the bad publicity…so we don’t have all the vaccines we might have had.
 
Wild animals are a key way these viruses spread. All corona viruses originate in bats but then end up in some other animals and only then in people. Eg: MERS which was a worse form of corona was transmitted by camels. MERS had a 35% death rate but was far far more difficult to spread human-to-human but EASY to spread camel-human. 
 
There is a “severity bias” with COVID-19. This means you only hear about the very small number of severe cases because they end up in hospital being tested. Most people who get it – you included – would probably never know you had it.
 
In 2009 the H1N1 virus looks like it was worse. In the US alone well over 200,000 infections and 12,000 deaths. This new one looks to be “mild to moderate” – it won’t “go away”. Viruses are just a part of life. This coronavirus may end up “endemic”: we may just have to live with it for years.
 
The Australian government is overreacting. We cannot contain it. We just have to be resilient and help the rare people who get really sick. Politicians tend not to get punished for over reacting on these things. But they should. China overreacted majorly, according to this expert, because the virus could never be contained and now it sets a bad example for other countries and when it breaks through the containment people will think that containment never works. It does…but not for this virus.
 
Masks are not needed for the general public.
 
This virus is especially not severe for children.
 
Wash your hands.
 
Modern healthcare systems really reduce fatality rates. Eg: ebola was thought to have a 90% death rate….but simply giving people IV fluids in a hospital reduced that number to 20%.
 
The main effect on the economy is due to misinformed shutdowns by the government.

Stop panicking. 
 
 
 
 
 

“All evils are caused by insufficient knowledge” is what David Deutsch has called "The Principle of Optimism". A reason this is a principle of optimism is that it means whatever is going wrong - whatever the evil thing is - whatever we no longer want (or do want but don’t have) is just due to some lack of knowledge (in other words: ignorance) on our part. If we try to create knowledge, seek solutions and search for answers, then with effort - sometimes great effort - we can find them.

Logically this is simply equivalent to “problems are soluble”.

There is some confusion, I believe following deeply entrenched traditional religious memes - about how “evil” should imply intent. This too is a moral claim, of course, about how words should be used. I guess the idea evil must entail intent comes from the idea that there was once considered to be “anger of the gods” or other beings (so natural disasters have traditionally been interpreted in the pre scientific era as evidence of god’(s)’ anger. When we learned lightning was just static electricity sparking, we regarded there as being “no intent”. So god's anger (or perhaps the anger of demons or whatever) was not there, so how can lightning be an evil?). Even avowed atheists inherit this way of speaking and thinking to some extent. Evil can only be evil if there is intent. "...the line dividing good and evil cuts through the heart of every human being" wrote Solzhenitsyn. This can be interpreted in a number of ways. Here's two of them. (1): there are mystical type forces (Satan versus Yaweh, say) or even just "psychological forces" pulling the soul (or mind) in one direction or the other. (2) People possess genuine knowledge (the good) and far more ignorance (sometimes bad) and the latter can cause real suffering. People can also sometimes know what just isn't so: and that's a form of ignorance which can also cause suffering of an even worse kind. The first "force" type way of thinking can be a useful way of framing things but it can also mislead one into thinking that all evil actions must be motivated by evil intent. But they need not be, even if evil philosophies - dogmas of all kinds - can act very much like psychological forces. But there too a person is a victim as much an as active agent. Their intents are shaped very much by ideas they learned on mother's knee and for which they only have partial responsibility because they are only dimly consciously aware of them. Many ideas are unconscious or inexplicit: and if one doesn't know one even has an idea which is directing one's behavior to what extent is one responsible for that idea?

It is often just rank ignorance that causes a person to commit an evil act. People can intend great good - have the best of intentions - and yet they are so profoundly ignorant and mistaken they cause the worst kinds of suffering. It's been well documented certain kinds of suicide bombers apparently feel nothing but (apparently) positive emotions: joy, ecstasy and elation. Even if these emotions aren't actually positive in any ultimate sense, the INTENTIONS of these people are good* - they’ll send their “victims” to heaven - eternal paradise where they can eventually be reunited with everyone they love. So do such people have evil intents? Clearly not. They are motivated, on some accounts, by deep love as perverse as this may seem. (See here for that: https://samharris.org/islam-and-the-misuses-of-ecstasy/) But it’s evil nonetheless. Their intentions don't matter to the evil of the matter at hand.

Intention does of course make an important difference in a legal sense (though I disagree with some of what the legal system has to say about this: for example that "mental illness" is a defense because the intentions were different - but this is beside the point for now). But there is a clear difference between accidentally knocking someone into traffic and deliberately pushing them. There, intent is everything. In either case a civilized legal system shows compassion, but in the former it might very well result in no gaol time at all, while in the latter one should probably be locked up until a very good explanation is known about whether one is predicted to do that sort of thing again.

I recall quite vividly having a thought myself around age 8, when in Catholic Church, hearing about all the ways we might end up in hell and how salvation came through baptism. I reasoned myself into what I thought was the best possible thing that could be done for the newly baptized: swift death. Indeed what would God think, I wondered, if someone took on an "Angel of Death" kind of position and went around quickly murdering anyone newly baptized so that they went straight to heaven? And what if that person's thoughts were "even if I get sent to hell, I feel it worth it because I have saved so many souls" - wouldn't God look favorably on such a serial killer? Wasn't that be almost like Jesus or even better: the sacrifice of oneself for so many others? Why don't well meaning people just murder babies right after baptism? Why don't loving parents? Are they selfish? After all - babies are necessarily innocent and would go straight to heaven once the original sin had been removed. I couldn't find a logical loophole. I still cannot...except that I've relinquished much of that religious mindset. But the point is: the intention can be of the greatest good, though terrible suffering (evil!) follows. And why? Because it's the ignorance that makes the difference here: a serious lack of knowledge about reality. There is no supernatural heaven and no God to reward such an Angel of Death.

But if one remains unconsciously in a religious mindset, one thinks “evil” necessarily has to be about intention. One might say a person has evil intent and only people can be evil and so on. In reality, let’s just observe that the typical “evil genocidal dictator” seems to think they too are doing good purifying the world. They have, in their mind, “good intentions”. Of course we see their behavior as abominable. I think it more parsimonious to just say: problems can be an evil. A hazard. A real threat to life, liberty and the pursuit or actualization of happiness.

But if you insist “Only people can be evil” very well. *Shrug*. The terminology doesn't matter to the Principle of Optimism which runs deeper than whether we use the word "evil" or something else.  Lightning that strikes an innocent child is, we must admit, a bad thing. What’s a bad thing? A problem - in particular a problem that causes some kind of suffering rather than one which elicits joy. 

A bad thing? An evil thing. It doesn’t really matter what words you use. I like David’s formulation of “evils are due to insufficient knowledge” - I think it’s quite right and it follows in a lineage of usage of the word that tries to capture something of its fundamental relevance to morality and of course illustrates, therefore a deep connection between what might have been hitherto thought the separate domains of morality and epistemology. But if some people would rather we just say “bad stuff is caused by insufficient knowledge” or just “problems we’d rather not have are caused by insufficient knowledge”  or even "suffering is caused by insufficient knowledge" so be it. It seems that these are just logically equivalent ways of saying the same thing.

“All bad things from murderous intentions to murder, from traffic jams to jamming fingers in doors, from Earthquakes to being hit in the head with rakes, from falling down stairs to attacks by bears and solar flares: these are all bad things and all are caused by our lack of knowledge. If we know how to prevent people having murderous intentions, we should prevent them, if we can find the knowledge needed to predict and stop Earthquakes or mitigate their destruction to zero - we would and should if we could. It all means the same stuff. I’ll continue to call these things “evils”. Of course an earthquake has no intent as such - it’s not motivated, twisting a moustache and concocting plans about how to hurt lots of people. It literally feels nothing (panpsychists aside). But then apparently nor does a psychopath feel anything, or rather anything but joy (though I’m not convinced).

And once more this highlights “other” kinds of approaches to morality and epistemology that call themselves “objective” but in fact fall back into subjectivist “what’s going on in your mind?” and “how does a person feel?” kind of way of thinking. That “objectivism” is at heart subjectivist for that reason.

Actual objective morality and epistemology says: feelings are not the criterion. Private thoughts are not the criterion. What matters is what goes on out there in the real (ontologically objective) world. Are problems being solved or exacerbated? Problems being solved: that’s a good. And being exacerbated: that’s an evil. And why would problems be exacerbated? Because someone somewhere (perhaps everyone) is lacking sufficient knowledge. Recently in Australia many lives and homes were lost in bushfires. One reason is that very well meaning people did not want so-called "back burning" to occur (the preemptive burning of forest and undergrowth around people's homes). Well meaning people didn't want the environment hurt, others didn't want people hurt from the smoke coming from the back burning. No one intended and no one really foresaw the December-January bushfires around Australia. Those bushfires were exacerbated by insufficient knowledge. And the death and destruction was a real evil. Yet no one intended evil (modulo arsonists - but again many of those were children ignorant about the possibilities and others even more ignorant than that). Evil isn't a parochial property of individual minds (though it can be that) - it's just a problem that causes suffering. And natural disasters on this view are an evil to be solved.

​Or if you want they're just "bad things". I don't mind. :)

Clarification:
*When I say above "the INTENTIONS of these people are good" I am merely conceding the way the words "intention" and "good" are often used. Namely: if one feels one is intending to do good...then one really is intending to do good. But there is a philosophical subtlety here: one can intend to do good and yet still have bad intentions. This is the difference between a "subjectivist morality" and an "objectivist morality". On the former thesis (subjectivist) things are good to the extent people think they are. It might be yourself in your own life or some kind of consensus (a greatest good argument). On any subjectivist view: it's about feelings and/or personal psychological states including states sometimes referred to as beliefs. So if you really truly believe (or feel) that you're trying to do good...then you are in some way. But on the objectivist view, this is all mistaken. It doesn't matter how you feel: it matters what happens in the world by the measure of: are problems being solved or not? Now on that view your intention does not matter a jot. Your intention can be utterly mistaken. Moreover because morality isn't about personal psychological states we also do not condemn a person for that personal psychological state that was mistaken. We simply correct them. Error is the natural, near ubiquitous state of things and all of us are "equal in our infinite ignorance" as Popper said. So a person who intends to do good (our proverbial suicide bomber thinking they are sending those murdered souls to heaven) has an objectively evil intent. Their own feelings on the matter don't matter. Murdering innocents destroys many means of error correction (namely people) and that halts progress in some ways and slows it in many ways and creates all kinds of terrible problems while solving none. That is an objective state of affairs having nothing whatsoever to do with feelings and beliefs and other private psychological states. We can talk about suffering as a problem - even a painful one and the solution of it without ever worrying about receptors in the brain or, in abstract moral terms, being concerned about how it feels or why it's unpleasant. We just recognize: it's a problem that needs solving. And compassion for others and fast progress in this domain depends on us not getting hung up about who feels what exactly and why. The application of criticism to creative solutions about the problems that harm us most depends on us soberly, rationally applying reason. Everything else is either going to slow us down or cause us to lose focus on finding the solution.

 After listening to the first half of the “Donald Hoffman with The Harrises’” podcast I wrote down a bunch of thoughts here. I found little to disagree with, because so much sounded like something between mainstream ancient philosophy (we don't have direct access to ontological reality) and the work of David Deutsch in "The Fabric of Reality". So in the second half I was looking forward to hearing something controversial. It did not disappoint. What I want to say at the outset is that although I ultimately disagree in places on points of epistemology and science and even whether Donald's theory even constitutes science, I think his overall approach is interesting and there’s no easy way to refute what he is saying. But this is just to say: almost any theory of consciousness is not easy to refute. Panpsychism is not easy to refute. As we have no theory of consciousness nor even a good working definition of what it even is, all approaches are more or less welcome at this point. So I want to say upfront: I think this is useful work. It’s worth trying. Almost anything is worth trying. That said, let’s get into trying to explain what he is saying and what criticisms one might conjure in response. Also: I actually read a couple of Donald’s papers to supplement his podcast. At times he seemed to deviate (especially under questioning from Annaka) with what he has said in published material. I’m going to stick with his words rather than try to argue with “the two Donalds” as I see them (spoken and written Donald). For what it's worth I read http://cogsci.uci.edu/~ddhoff/Chapter17Hoffman.pdf and also link.springer.com/content/pdf/10.1007%2FBF03379572.pdf and may get to commenting more on those in more detail at some other time.
 
Donald wants to find “a mathematically precise theory of consciousness” – and by this he means something like looking at all the ways consciousnesses interact (note the plural there: so we are conscious of course, but it’s not clear “how far down the phylogenetic tree” Donald sees consciousness as running. At times he even speaks as though he agrees with panpsychism and Sam basically seemed to put him in the panpsychist box at times – and I tend to agree) – but whatever the case he wants a way of mathematizing the relationships between individual instances of consciousness. So he talked about, for example, big data and how we might use that to analyze how humans interact online and everywhere else. If he could analyse these interactions or model them in some way then he could have some sort of mathematical description of what human consciousnesses are doing. This was an interesting approach to my mind because he was contrasting it to the “usual” way of doing things which, as he explained, was basically to look “in” matter for consciousness. So most people begin with neurons and try to work their way to consciousness. They start with the physical and try to get to the mental. Donald said he was trying to take the opposite approach. He’s doing this, he says, because he’s motivated to find a “dynamics” of consciousness. But for this he needs a mathematically precise definition of consciousness. He says he has such a precise definition. Now I should say: definitions are one thing – but people have tried defining something like “the electron” again and again and it’s no easy task. And, along with Popper, definitions are possibly misleading and always fallible anyways. What we need are explanations. So right away Donald is sort of in an instrumentalist camp. We will return to this. Whatever his "mathematically precise" definition we never actually hear what the rough-in-English definition is.
 
Whatever the case – at the 1 hour and 14 minute point in the podcast I hear the first remarks I can really begin to raise my eyebrows at – although not disagree with out of hand. What he claims is that his notional theory of consciousness – his “conjecture” one might say – is that consciousness is the most fundamental thing in the universe. So it is more fundamental than quantum field theory and general relativity and evolution by natural selection and indeed everything else we basically know of science. So his theory, if correct, must be able to generate quantum theory, general relativity and evolution by natural selection and everything else. And indeed he'd be right that the latter follows from a theory purporting to be the most fundamental of all. He says at one point “All of these scientific theories are wonderful tools but they have only been the science of our interface, not science of objective reality.” On this view even space-time is part of our “user interface” that he defined in the previous hour.
 
Now here is where I may part company with him. What is the role of science then? And explanatory knowledge generally? If we are trapped inside this user interface – a sort of Platonic Cave – then science becomes about us - a parochial arm of psychology. It's about what we are doing and how our brains (or minds, I'm not clear) are doing. But I'm not sure on his thoughts about the relationship between brain and mind (see below). Even general relativity, on this view, is mainly about us – and not a separate space time. It seems on Hoffman’s view space time is not “out there” but rather “in us” in some way - as the manifestation of an interface with objective reality or an interface between conscious creatures, or something. Now I am of the view: general relativity is a theory of stuff out there – it describes a really existing space time. Now could it be the case that general relativity gets refuted? Not only do I think this could be the case, I think it must be the case. In some ultimate sense it has to be false because (1) it disagrees with quantum theory so there must be a deeper theory than both (2) as a matter of principle all theories are improveable – we cannot have a final theory. If general relativity is the final word we must ask: WHY? And if there is no answer to that question we can find, progress stops and we are doomed because some problems are insoluble not because a physical law says but because our capacity to understand the universe is bounded by a brain that is unable to grok something about physical laws. This would mean our mind is not universal (now I just as an aside admit here that in some places – namely here: http://cogsci.uci.edu/~ddhoff/Chapter17Hoffman.pdf) that in  Hoffman straight up admits: the mind is not what the brain does (see page 11). I am unconvinced and he never grapples with the universality of computation anywhere - not in the podcast and not in his two papers that I read. This is a deep problem for his thesis, so far as I can see it. And his quick dismissal of actual, literal, realist quantum theory is probably also disqualifying. But then, few physicists take quantum theory as being literally true. We’ll come back to this also.
 
The idea that spacetime is part of us, or of “consciousness’ user interface” seems to me to be the mistake of thinking that a scientific theory is at best a fiction – perhaps a useful model – but not really connected with reality. This is an epistemological claim. A realist says: no – although ultimately false, scientific theories are not merely fictional though useful models. They are accounts of what is actually there. There is a connection, therefore to ontology. Hoffman seems to be discounting this. Even if some consciousness theory is deeper than all other scientific theories this does not mean those other scientific theories never have a basis in objective reality. Consider by analogy any other demonstrably false theories. I’ll go to my favorite example: Newtonian Gravity. It says that there exists a force between particles that varies inversely as the square of the distance between them. Now that theory has been shown by experiment to be false. But is it utterly false? A complete fiction? No. There really is a way that particles influence each other in space (so that's correct) but it is via the spacetime between them. Einstein’s general relativity replaces Newton’s theory but it does not say of it: utter fiction. The motion of things in space does indeed approximately obey the inverse square law. It’s not a random guess. Approximations are approximations to something: and they cannot be approximations to simply other complete fictions. They have to be getting to something if the predictions being made are reliable to some extent (more than random guessing).
 
Whatever the case: Hoffman argues that because his theory of consciousness means consciousness is more fundamental than space and time that it means consciousness itself is outside space and time. Well…that’s rather neat. I don’t think there is the slightest bit of evidence refuting the claim that consciousness is IN space and time, but there we have it for now. We need an experiment (and more precise theories too) in order to decide between the two claims: consciousness is inside space time vs consciousness is outside space time.
 
Annaka asked a question about “The Fundamental Nature of Reality” and this comes up more than once. Hoffman responds at this point that his theory of consciousness would indeed answer to that label. So, ultimately, Hoffman believes in an end-to-science: he thinks there can be a final theory and that he is on the way to finding it. It won’t explain “everything” – he concedes that – but within the realm of fundamental physics – he would have a final theory. It would be non-improveable (he doesn’t say this: I’d like to ask him – but his language is telling “final” and “fundamental nature of reality” and so on). So while he doesn’t think quantum theory or general relativity or natural selection can be the final word (quite right) he does think his theory could be. 
 
But once we have that theory, why can we not ask: why isn’t it some other theory? Like if someone came up with an alternative – why must it be ruled out a priori? Will his theory explain why all other theories are not possible? And if so, will it then explain why his mathematics is infallible? Why he cannot possibly have made a mistake and so on? These claims to “absolute final theories” all run into these questions. The alternative is: however deep your theory goes, that is no guarantee you’ve reached the bottom. There may be no bottom. There may just be better and deeper places to delve. 
 
Hoffman speaks of his theory of consciousness as describing consciousness as a “field” not unlike the fields in a physical theory. I suppose he might think – though he didn’t say this – that particular instances – your mind and mine – are excitations of that field rather like the way electrons and photons are excitations of the quantum field. I’ll need to read more about this to find out but that could be a neat idea. Annaka rightly observed that this means this would be a field outside fields – so a field outside spacetime. But Hoffman says he is using the word field in a different sense to that in quantum field theory but admits the conscious field will be outside spacetime (see the 1 hour and 18 minute mark).
 
Soon after Sam interjects with a question about panpsychism. Incidentally Sam says a thing he often has: consciousness is the one thing that cannot be an illusion (following Descartes). Hoffman is no fan of panpsychism and rejects the label because he says unlike the panpsychists he is not starting with the material world as an assumption. So Sam later suggests he is an idealist. Hoffman also rejects that label. On the "cannot be an illusion" thing, I used to think the same. I was talked out of it by David Deutsch. My own way of putting this now is: what's not an illusion? Consciousness? What about that string of letters? Does it infallibly label what you think it does? Is that an illusion? If it could possibly be, then what exactly is not an illusion? And given we know that this moment actually is being experienced in the future in some sense (because neurons take time to fire), then consciousness is already a complicated thing that could be illusory. But I digress. 
 
Hoffman makes some interesting remarks to further explain his “user interface theory”. He says: when you look in the mirror you see skin, hair, teeth, a face and so on and yet you know there are emotions, sensations, hopes, aspirations there. So the face is like a portal – it’s an icon so to speak – which gives you access to consciousness. So too with other people. Now I quite like that. But he then goes onto say that a cat is an icon for consciousness too although it’s “dimmer” (his word) – he thinks this as he can tell his cat likes some food but not others. Hoffman then goes even further: a rock or a glass of water is an icon of consciousness. Now at one moment he rejects the idea that the rock or water are themselves conscious – instead he says the consciousness is “behind” those icons in some way. And some of those consciousnesses are greater and lesser than ours. This is where he lost me. He seems to be saying that what we see as rocks or glasses of water and so on are the means and ways in which we conscious entities interact. At least that’s my steelman version of what he is getting at. After all – were there no physical objects out there, what point would there be in consciousness and what would we have to interact about?
 
Sam rightly suggests that this is all panpsychism but it’s in virtual reality. 
 
Hoffman dismisses the quantum multiverse for poor, sadly incoherent reasons revealing a level of ignorance about quantum theory. He says, for example, that it “does not explain the measurement problem”. I do not have the time here and now to explain entirely why that’s wrong but here is a brief sketch:
 
The so-called “measurement problem” is the question as to why before a measurement is taken in quantum theory, the mathematical formalism describes a system (say a single electron passing through a slit) as taking all physically possible paths. Upon measuring it on the other side of the slit (the observation) we see only ONE path having been taken. But the very point of the multiverse is to take seriously all those paths described by the formalism as equally real before, during and after the measurement. They all exist. But you only ever see one because you only occupy the one universe (in a sense, speaking loosely). But quantum mechanics describes many many universes. This is really not that mysterious. It’s rather like how even Kepler’s laws describe an orbit as consisting of many many points in space…and yet Earth is only ever observed at some point in time to be at one of them. The others really exist though – but we’ll never observe the Earth at all of them. Sure: we can take photos, perhaps when it’s somewhere on January 1stand then 2ndand so on. But we can do the same for the electron – repeating the experiment and noticing it really does take all the possible paths. Whatever the case, Hoffman fundamentally – deeply misunderstands what quantum theory says and how the multiverse solves these misconceptions people have.  (Look forward to an upcoming ToKCast for this in just two episodes when we go through “The Multiverse” chapter of “The Beginning of Infinity”…or if you can’t wait – read it yourself now!). For anyone playing along I've written a number of short articles on The Multiverse like this one.
 
Hoffman is thus also confused about the relationship between quantum theory and probability. I recommend https://www.youtube.com/watch?v=wfzSE4Hoxbc which, in a strongly competitive field of amazing talks by David Deutsch is right near the top for me. The long and short of it here is that: randomness is always just subjective. In the multiverse everything that can happen really does happen. So it happens with Probability = 1. Probability was invented to explain games of chance but has been repurposed and perhaps even perverted for all sorts of things that it perhaps shouldn't be. Now in the case of the multiverse some things happen more often (with so-called “greater measure”) than others but happen they do. And doing probability on infinite sets doesn’t make sense because we can never “do infinite probability experiments” to check if our theory of probability is actually correct. If the theory is supposed to be about the physical world we need to be able to test it against the physical world. So probability theory runs into this deep problem of being untestable. And if it's not supposed to be science but rather a branch of pure mathematics, then it doesn't apply to the real physical world. Whatever the case: Hoffman says that quantum theory simply does give us objective randomness which is a terrible mistake and a gross misunderstanding of the theory. But these misconceptions are all intimately tied together and I think a conversation between him and David Deutsch on this point would be fascinating. But for now, if you do read this Donald – please watch that video and read David’s book “The Beginning of Infinity”. I say this not because I'm wanting to refute your entire thesis but rather - like Annaka - I think there could be something there which might be improved by fixing up these quibbles I have. Moving on…
 
Free Will: Hoffman broadly agrees with Sam about free will but at the same time Hoffman uses the word “agent” with rather wild abandon in places JHe is tripped up on this by Annaka and it’s not entirely clear what he means by “agent”. He does say he has a mathematical description of what “choice” is and how choice must arise from unconscious factors and hence these choices cannot possibly be real (free) choices. He goes so far as to say (on his theory): you cannot be conscious of making a choice because the mathematical formalism says as such. But I think most of us refute this by personal experience. I am conscious of making a choice and no matter what your mathematics seems to say: I'm choosing to finish this sentence.

This brings me to my most major gripe from the podcast and Hoffman’s approach:
 
Hoffman very heavily emphasizes the mathematics of his theory whilst deemphasizing experimental testing. He insists upon the formalism. It’s an interesting “tell” by which I mean: many of us have bemoaned so-called “scientism” – the application of scientific methods to problems that are not science (like purely philosophical problems like the very question: are there philosophical problems?) Scientism is something thought of as the stance that no knowledge is “valid” or some such except for scientific knowledge. Now I know this isn’t a word - and I tend to hate neologisms (a point I've made over and again) but I’ve often accused some of “mathematism” – the claim that mathematical theories have some special status or that without some formalism, the theory has less status. I think this is a mistake. Now I’m not (yet!) accusing Hoffman of making this mistake necessarily – he might think the mathematics just arises naturally. But the issue I have is that a scientific theory is typically able to be explained in natural language at least somewhat well to some crude resolution perhaps. Even string theory is about...well, strings - which can be rather simply described using words. I concede the pioneers of quantum theory often failed at this. But even they were able to say something in English. Hoffman doesn’t say much about what consciousness is exactly in natural language (i.e: simple English) – he just says it’s “mathematically precise”. Now this may be all well and good to some extent. For example: we should take something like The Schrodinger wave equation seriously. And that equation – the equation that describes (for example) the motion of an electron over time as having a wave-type shape – tells us that the electron really does occupy many possible places simultaneously and can take many possible paths simultaneously. It is taking this equation – the mathematics - seriously that leads us inexorably to the multiverse (among other things). I hasten to add here: the electron itself is not a wave: it is a thing that can occupy a “sharp” position in space – but the wave aspect means that it has many (initially fungible) instances that can take all the different possible paths. Now the difference here is that: there exist experiments in quantum theory. Many many experiments and observations. We don’t start with the formalism: we start with certain problems prompted by strange observations. In the case of quantum theory some observations are: patterns generated by certain interference experiments. So then we seek an explanation - a solution to our problem. And THEN we seek to formalize all that. This is science – this is reason. It seems to me that Hoffman has no problematic observations he’s really trying to explain. I mean: he has consciousness but it’s not an observation of the form: if we see that, then this refutes my theory or is not refuted by my theory. Instead he seems to be defining into existence something he calls consciousness and then doing some mathematics. But we don’t merely define electrons (for example) into existence – we see their actual marks on photographic plates and so on. Experiments matter, so we absolutely need some experiments to check Hoffman’s thesis. But what would these look like? I cannot even imagine. And crucially we need so-called “crucial experiments” (see here for more about that). An experiment that decides between at least two theories about what’s going on. If the result goes one way, one is refuted and the other theory is not. But without a good working existing definition of consciousness how can we even begin to know how to test Hoffman’s theory. Test? Test against what? People fundamentally misunderstand the nature of science on this point which is why David’ Deutsch’s original paper on all this is so important. (And again, if you want the crib notes on that, see here). So Hoffman uses the phrase “mathematical precise” theory/definition over and again as though if he could just get this robust, self-consistent mathematical theory he will have explained consciousness and other things. But we must recall: Newtonian Gravity is “a mathematically precise theory of gravity”. It is also demonstrably false (which by the way is a strength of the theory: it makes predictions we can observe in the real world and when we fail to observe what is predicted while general relativity is shown to be accurate, we have refuted Newton). So “mathematically precise” does not mean true. Indeed mathematicians make up mathematics all the time that has nothing to do with reality. Famously, Hardy in his "A mathematicians apology" celebrated doing this. Like so many pure mathematicians, he regarded the subject as more an art than anything else.
 
Now I hasten to add here that Hoffman is no crank (so far as I can tell!) because he readily admits that because he makes the strong claim that consciousness is more fundamental than quantum theory, general relativity and so on, that if his theory cannot produce quantum theory, general relativity and so on as “limiting cases” then his theory is absolutely false. So that’s something at least. 
 
Hoffman invokes Godel’s incompleteness theorems (always a bit of a red flag to me) but not in a too egregious way. He concedes with prompting from The Harrises that taking LSD or mushrooms might help him because Hoffman says that he has never so much as smoked a cigarette. He has said he has spoken to friends who are “experienced psychonauts” and what they report back are certain visualisations and the feeling of being “outside spacetime” that are in very good keeping with his own theory. But of course: that would be some kind of empiricism: knowledge coming from the external world…wherever that world might be. 
 
The final question from Annaka is perhaps the best one as it reveals something about the thought processes of everyone in the conversation, so I’m just going to transcribe the question and the answer in full and make some remarks afterwards. Italics and boldface are my emphasis.
 
Annaka: “Doesn’t it seem that where we’re left with all of this is that even if you’re able to make great progress with the math and with the theory and that you’re able to come to some point of feeling that you’re confident that this is correct or likely to be correct, what would constitute proof? It seems to me to be outside the realm of scientific experiment. When we’re talking about consciousness you could tell me there’s some theory that says that there is consciousness in the atoms of the sofa I am sitting on but how would we be able to confirm it just seems to me it’s impossible to confirm, so I’m just wondering if there’s some sense in which this can result in some type of scientific experiment or what would result in proof?”
 
Donald: Right. That’s a critical question for a scientist and the bottom line for me is that if my theory of consciousness when I project it back – so I have to have theory  of consciousness and it’s dynamics that is absolutely precise. I have to have a mathematically precise mathematical function that projects it into our spacetime interface because that’s where we’re going to get any data for our experiments. And then the first thing – the first test of my theory will be – if the dynamics when it’s projected into space time does not give me back all of the consequences of evolution by natural selection, general relativity, quantum field theory…if I cannot do that, I’m wrong. I’m flat out – I’m wrong. So already all the sciences we have right now are going to be an acid test for this deeper theory. 
 
Annaka: Except that your starting with this base assumption that you’re calling this foundational math – you’re saying that it represents consciousness but I’m just wondering if there’s any way that that can be confirmed or will that always be an assumption?
 
Donald: So…what I will be able to do is to see if I’m wrong. Right? So if there are things that if I cannot do them, the theory is absolutely wrong. What I cannot do is prove that I’m right. But that’s not unique to my theory. No scientist can ever prove that they’re right. The best we can do is get evidence that either disconfirms our theory or reduces our credence in the theory or that in some sense increases our credence in the theory. But it’s sort of an elementary point in the philosophy of science that no scientist can ever prove their theory. And even falsification in the strict Popper sense – you may not strictly be able to falsify a theory – you may, because there are so many auxiliary hypotheses that go into a theory that you don’t know which one is the faulty one. But, my theory can be tested as much as any scientific theory can be* and one test that I would take as absolutely critical is if I can’t get back evolution by natural selection and say quantum field theory when I project into our spacetime interface I would take that as clear evidence I’ve got the wrong theory of consciousness.
 
My comments: I’m going to leave aside all of the anti-Popperian stuff there more or less: lots of talk about “prove” and “confirm” (anti-fallibilist notions of science or confusion between purely deductive systems like mathematics and explanatory sciences like physics) and “confidence” (reducing epistemology to feelings) and even “credence” – the Bayesian mistake (I explain some about that here). As to “cannot strictly falsify” – this is The Duhem Quine Thesis and is all very well. And we cannot prove it true. Indeed. 
 
But this claim that the test of “getting back” quantum field theory is an experimental test is a little dubious. I mean, he’s strictly correct that if he makes the claim everything else is emergent and his theory is fundamental, that if he cannot produce quantum field theory then he’s wrong. But quantum field theory rests not just upon the fact that classical mechanics is a limiting case of sorts but rather many many real world observations only explicable by quantum theory. So can his *theory can be tested as much as any scientific theory can be*? I don't think so. Consider: in the case of quantum theory alone. It is testable against:the photoelectric effect, Compton scattering, radioactive decay, interference experiments, quantum computation, etc, etc. I mean a deep theory seeks to solve many discrete problems and is tested against novel observations and experiments. At least typically.  Even evolution by natural selection: solves the problems about homologous structures, the similarity of DNA, embryos, the fossil record, Galapagos finches, etc, etc, etc.  And General Relativity: neutron stars and black holes, the precession of Mercury’s orbit, Eddington’s observations of starlight during an eclipse, the GPS system, etc, etc. But Hoffman’s theory – so far as I can tell – does nothing like this. So it's not as testable as any other scientific theory. Not by a long shot. What are its PREDICTIONS? It defines into existence something he labels consciousness – but he has not told us in the entire podcast what consciousness is in simple terms or what we might observe out there to notice if its on the right track or problematic because it's (say) postulating disembodied consciousness which direct the motion of clouds (or some such). So without a simple definition, explaining WHY that definition is correct except to say: here is some mathematical formalism from which we can generate quantum field theory, general relativity and natural selection and whatever else seems more like a mathematical trick than actual science. What predictions does it make BEYOND just: here is a theory that has as limiting cases all other theories? That’s certainly interesting…but is it consciousness?

General relativity explains what gravity is: the bending of spacetime by mass/energy. And then it predicts things like black holes. Which are observed! And which predicts the bending of light during an eclipse – which is observed. And sure it “gives us back” Newtonian gravity as a limiting case…but that is almost beside the point.
 
So for Hoffman’s theory to fit this scheme I expect not only for his theory of consciousness to “give us back quantum field theory (and the rest) – it has to tell us what consciousness is exactly (as General relativity tells us what gravity is) AND it has to predict things we hitherto do not know about like black holes and allows us to test this theory by making precise predictions about what we should observe. And if the response is: but that would be about “the interface” and not “objective reality” we have a theory immune from experimental criticism. And that ceases to be science.
 
But this does not disqualify it because it could be very interesting metaphysics and the beginnings of an actual research project.
 
I have to read more of his material.
 
 
 

A number of people have recommended the work of Donald Hoffman to me. I am not very familiar with him – I have not read any of his books nor listened to his talks (like his TED talk). I think I will soon. What I have done is listen to the first 1 hour and 7 minutes of his interview with Sam Harris. 
 
I was expecting to encounter something other than I did – but I’m not sure what. Long story short: I did not find anything he said particularly controversial (I emphasize this as someone who has read Popper and Deutsch). I imagine what he says would be controversial to mainstream thinking about the relationship between mind, our mental models and objective reality – but linguistic quibbles aside, I found what he said to be refreshingly familiar to me. In particular what he said could almost have been conjured by anyone who has read Chapter 5 of "The Fabric of Reality" by David Deutsch. It was that close...some minor linguistic quibbles aside and perhaps some hints of relativism. 
 
So, some notes on the conversation, roughly in chronological order in which they occurred in the podcast:
 
Hoffman says he is reacting against his colleagues (in psychology, I presume) who he says regard evolution as having shaped us to “see truths about the world”. In other words to see the actual, final truth in a sense – or objective reality as it is. This is all well and good. In Popperian terms: he objects to empiricism (the idea we derive knowledge about reality from our senses) – and quite right too.
 
Hoffman gives an account of his “user interface” idea – which, it seems to me on a cursory understanding of what he said in this podcast, is perfectly harmonious with the idea that we do not have direct access to reality. Indeed. We will come back to this later with a discussion on virtual reality. This is inline also with what Plato, Descartes and what the the Wachowskis conveyed in the Matrix and various other movies have told us over the years. What we tend to experience isn't reality exactly and we could be terribly deceived. Thinking we're actually in a Matrix is, of course, a step far too far. But the point is: our senses can deceive us and may not always (or even typically) give us reliable knowledge of objective reality.
 
Annaka Harris points out during the discussion that “we don’t know what light is” and “we don’t know the fundamental nature of reality.” I only have a linguistic quibble on the first point: we do know– so long as one takes on board the Deutsch/Popper notion of what knowledge and “to know” is. It means: have a fallible explanation of. It does not mean “grok the final theory”. So we know what light is – but we don’t know what light ultimately is. We never shall. All theories must be improvable because we don’t have direct access to reality. But we can gain fallible knowledge about light (and everything else) to some extent. As for not knowing the fundamental nature of reality: yes, correct. And uncontroversial so far as that goes for a critical rationalist/fallibilist. For more about what "to know" means see here for a brief explanation.
 
Hoffman says that “belief in science is not a helpful attitude” - which is to say believing scientific theories is not a helpful attitude. Wonderful. If he has not read Deutsch or Popper, then he has independently converged on that epistemological worldview to a large extent. Hoffman regards scientific theories as “the best tools we have so far”. A minor quibble on the use of “tool”. Tool conjures up a device for just solving certain problems. Now it depends on one’s emphasis here: if the only purpose of science is to predict (a tool for prediction) – I disagree. That is one thing science can do. But science gives us some approximation to reality as well. So I regard scientific theories as tools that tell us something about objective reality – they give us some account of what is really there. Hoffman seems to more or less agrees with this in some later remarks.

At 41 mins in, Hoffman invokes “the virtual reality metaphor”. He talks about putting on a virtual reality headset and seeing race cars in a computer game. Obviously the cars don’t actually exist. Now he says this is basically the state we are always in. Yes – exactly. I guess Plato would not disagree about this (the shadows on the cave wall being not the objects in themselves – and we are trapped in the cave (the VR simulation).) Now in “The Fabric of Reality” chapter 5 is titled “Virtual Reality” and it is a long thesis precisely about exactly this point and some other things. This "virtual reality" explanation is no mere metaphor either: we really are simulating the external world in our minds using sense data. David writes on page 120 in that chapter, “So it is not just science – reasoning about the physical world – that involves virtual reality. All reasoning, all thinking, all external experience are forms of virtual reality.” I actually think David is making a stronger claim even than Hoffman. David published his book in 1997 – that seems to predate anything of Hoffman’s on the topic by over a decade (I can see the user interface theory was published in around 2010: https://link.springer.com/article/10.1007%2FBF03379572) and of course Plato wrote about his cave in around 400BC - so these kinds of ideas, or aspects of these ideas have been refined and rediscovered or reformulated again and again.
 
Hoffman admits “something” is there in reality but he says he just doesn’t know exactly what. The word “exactly” does a lot of work there. The sentence is true with it, and false without it. Annaka says “We do not understand the deeper reality” (the reality deeper than the one more fundamental than what quantum theory says) – and of course this too is correct and uncontroversial: we do not know what we do not yet know (in this case, what the successor to quantum theory will say…and what the successor to the successor will say and so on).
 
David engaged with at least some of Hoffman’s ideas here: https://twitter.com/stealthytooth/status/723555137478905856?s=20
And that language Hoffman uses which seems to deny the existence of objective reality (or parts of it - they mention the moon and a glass of water on the table) he tightens up – corrected I should say by Annaka Harris. It seems Hoffman steps back from the claim there is no objective reality or that the moon or glasses of water in particular don't have an objective reality. So he can have a habit of sliding into a sort of soft-relativism or something…yet when pressed seems to concede realism. At one point Annaka rightly interjects when Hoffman uses the word "miracle" to describe "premises of a scientific theory". Hoffman seems to needlessly confuse the reader or listener with terms that make things seem more controversial than they are. A premise need not be regarded as a "miracle" (some mystical violation of physical law) just because it cannot be derived from any known theory. Hoffman admits he should just use the word "premise" or "axiom" instead. It is this kind of style that, it seems to me, may make some of his ideas sound more controversial or counterintuitive than they really are.
 
Overall, I liked what he had to say, with some minor quibbles over his use of language – especially that which touches upon anti-fallibilist thinking (but this is true of almost anyone who hasn't taken Popper on board). So, so far, what he says seems roughly in line with what David wrote in Chapter 5 of “The Fabric of Reality”. But I stopped the podcast just as they were beginning a discussion of free will and consciousness. I guess what comes in the next hour and a half of the podcast could prompt something else...but so far I am nodding in broad agreement and didn't once roll my eyes. 

In around 300BC, in Euclid's "Elements" the oldest known proof of Pythagoras' theorem was published. There are possibly more proofs of the theorem that in a right angled triangle "the square of the hypotenuse is equal to the sum of the squares of the other two sides". Early on in high school usually c^2 = a^2 + b^2 is given without proof and students (sadly) "drill" special cases. Like if c=5 and b = 4, what is a? The theorem is assumed as true. But what if an inquisitive student asks "How do we know it's true for all cases?" Short hand we can say: It's been proven. And if the student asks how, we can provide one of any of the approximately 367 proofs there are.

Now E = mc^2, also called the "Mass-Energy Equivalence" can be considered a law of physics. (I just note here as an aside that E=mc^2 is the "non-relativistic" case. It's not generally applicable because it only "works" in the rest mass of the object with mass. But this is irrelevant to my point, so we can skip past this complication). Einstein was the first to discover it. But how? Well, via a proof. He derived it. How do we know E=mc^2? Because it's provably the case. How? Well, what Einstein did was begin with his two "postulates" (first: the laws of physics are the same for all observers and second: the speed of light is constant). From these postulates he proved the so-called "Lorentz transformations". And from there the kinetic energy of particles can be derived and...long story short, he concluded - he proved E = mc^2. So he didn't begin with the assumption that E=mc^2. He began with the two postulates. Everything else just followed as a matter of mathematical necessity.

A proof just means, in "critical rationalist terms" we have found a very good (exceedingly hard to vary) mathematical explanation of something (we may call it a theorem in mathematics or a conclusion in logic or a law in physics (these are not strict terms - they are rough)). Of course, if we find that the premisses upon which Euclid's elements are based are false, or the premisses upon which even deeper theories of geometry are based are false, then we would refute Pythagoras' theorem. And if we found Einstein's postulates were false, this too could refute E = mc^2. But this whole - quite reasonable - notion that we should expect things we know not to be perfect and thus to be improvable is not a prescription for not taking seriously what we know (fallibly) today. We can use Pythagoras' theorem and E = mc^2 to solve actual problems today. So too with David Deutsch's proof of Turing's Principle in the context of quantum theory. 

So when we say "David Deutsch proved the Turing Principle(1) in 1985 that "every finitely realizable physical system can be simulated to arbitrary precision by a universal model computing machine operating by finite means" (2) we mean that beginning with some uncontroversial assumptions from mainstream quantum theory along with what was already known from classical computing as discovered by Turing, he was able to reach that conclusion. So he didn't begin there. He reached there on the assumption of known physics.

So to say something is "proved mathematically" is not to give it a special "less-than-fallible" status. But it is to give it its due as a good explanation. But the full explanation as to WHY the "principle" is to be regarded as a "law of physics" isn't just any old "good explanation" because it's an explanation not only in terms of natural language but also largely in terms of a mathematical deductive system. So that gets a special name: a proof.

Now incidentally the proof has a kind of transitive nature to it: on the assumption that quantum theory is true then any physical system can be simulated (to arbitrary precision) by a universal computer. But also: given the principle, then all physical processes can be regarded as computations; that is to say: quantum theory satisfied the Turing Principle.

The significance of the proof (and so the principle) for the nature of personhood (and thus "cognition") is that any physical system (so that includes us...in the form of our brains and minds) can be simulated by a  computer - or to "arbitrary precision" by a quantum computer. This does not mean the human brain is a quantum computer (many of us guess it will not be that because the human brain is warm and hence noisy - an environment quantum computers appear to not like) - we guess the human brain is just a classical computer. But it's a classical computer running a special kind of software. Whatever the case if a quantum computer - or indeed just a classical computer, but this is beside the point - can simulate a working human brain then it will be a working human brain - just made out of other stuff. It will be computing - performing the physical processes a brain does. Nothing spooky - nothing requiring new physics. And so - it will be running a mind. It will have a mind and thus it will be a person.

Perhaps take a moment to just consider again that sentence above. It is rather a profound claim. Not only does it takes "spookiness" out of the "what is a mind?" question it regards so called "Artificial General Intelligence" or AGI as a person and thus with the full legal rights and moral status of a person. Anything less is genuinely racism. The spookiness also removes caveats about an "analogy". That "the brain is a computer" is demonstrably the case for the reasons stated above is no analogy. It is mainstream physics. The mind is a kind of software: it's what brains do. It's the abstract software running on the brain. A mind in a human brain already is a simulation: it is simulating the reality delivered to it by the sense data that it interprets. So a computer that is able to simulate a mind really is a mind. Minds are abstract things. This is important because a quantum computer - or any computer - that simulates, let's say, a bullet...has not created an actual bullet. Simulated bullets are not real physical bullets. There's a difference there. If a computer gamer is playing "Call of Duty" and shooting bullets from a gun, neither the gun nor bullets are real. This should go without saying. But minds are not physical. They're abstract. So simulating them "to arbitrary precision" is to create them in reality. It's rather more akin to the person at the warehouse doing stocktake and adding up by hand all the products. They have many sums to calculate. Now if they do the calculation by hand with pen and paper or by using an abacus that's one thing. It's a real calculation. But if they then take the calculation and use a computer to do it: they are in a real sense "simulating" the action of the abacus or ink-and-paper calculation. In either case it's a real calculation and one is not more or less "real" than the other for being done with the hands or with a computer.

So we (humans, in the form of David Deutsch and anyone else who wants to try) can prove the "Turing Principle" and we can notice that as humans are made of atoms the principle applies to us just as it applies to any other physical system in reality. We can be simulated. But more than that we are computers too. But more than that: we are much more than computers. For more on that, see here: http://www.bretthall.org/physics-and-learning-styles.html or here http://www.bretthall.org/alien-intelligence.html

I've sometimes been told the principle is "just an assumption". It isn't. It's been proved. We are told time and time and time again that it's an analogy. It isn't. It's been proved.  That doesn't mean it's "infallibly the case" - it just means it's a conclusion...mathematically derived from what is already known about physics. If I was to be asked "How is it proved?" I'd be unable to do better than the paper itself. And that runs for around 17 pages and has to this date won the author a number of prestigious prizes in Physics...so it's not something that can be easily summarized in a blog nor on twitter. So I refer the reader to the original paper.

One of those times above is from the 2014 Edge Question "What scientific idea is ready for retirement?" and the author there is arguing "The brain is a computer". But actually this thesis seems very poorly subscribed if one does a cursory search on google for "brain is a computer" AND "neuroscience" we get stuff like this: faculty.washington.edu/chudler/bvc.html - and that's for kids. Now I am unfamiliar with the present state of actual neuroscience and the professional literature there but if popular accounts are anything to go by, there is still a strain of mystical thinking lurking there. The truth is, the brain is mysterious - but not mystical. We know it must be a computer of some sort, given The Turing Principle - but we don't have almost even the first clue as to what the software is that is running on that computer. That, so far as we know, entirely unique creative software that generates consciousness and the experience of freewill and - most importantly - new explanations. We know there must be some code that can be captured in an algorithm. We just don't know what it is. That of course is another story.
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(*) Note that "It's been proved" on the assumption quantum theory is true. So of course if quantum theory is refuted, then the proof is worthless. Like any proof, the soundness/truth of the conclusion is only as good as the premisses one begins with. Now I can imagine scenarios where quantum theory is, technically, refuted, but the newer, improved, deeper theory has quantum theory as a limiting case in which case the proof may still indeed be valid.
(1) Note that what the principle is called is a matter of some confusion. David Deutsch refers to the principle as the "Turing Thesis" in his original paper and the "Turing Principle" elsewhere. Some - like mathematicians Roger Penrose and Robin Gandy have insisted that Alonzo Church conjectured (guessed!) the same thing and so have called the same principle the "Church-Turing" Principle and still others have suggested it be called the "Church-Turing-Deutsch" principle as David actually proved the conjecture beginning with quantum theory as a premise. The upshot of that was that computer science then became a branch of physics because computers were no longer the ideal mathematical objects supposed by Turing (or Church for that matter) but rather real physical objects that obeyed the physical laws known as quantum physics. And of course they must because all computers are made of matter and not Platonic Ideals.
(2) Note that this is not the way the principle is put in the original paper found here: http://www.daviddeutsch.org.uk/wp-content/deutsch85.pdf I have changed the phrasing. The original formulation is "every finitely realizable physical system can be perfectly simulated by a universal model computing machine operating by finite means". David knows better than most that "perfectly" isn't correct and, though I cannot find it, I recall a tweet exchange between himself and quantum physicist Michael Nielsen on exactly this point.
 

 Somebody asked for some comments about this video: https://youtu.be/OoIcsj9ysvs . It is an attempt to criticise the optimism of people like David Deutsch - but the more explicit target seems to be Steven Pinker. It is not an easy watch for people who are familiar with optimism. Not because there is any substance to what the speaker says but because it is (a) frustrating and (b) one knows that this sort of thing will be latched onto by many. It purports to be a reasonable analysis. It is anything but. Here are some quick responses because something longer I am afraid isn't worth the time. In line with David Deutsch's own approach to these things, time is far more fruitfully spent working on solutions - and therefore having an actual optimistic approach, than dealing with all the false ideas out there. This was just a litany of false ideas. But the motivation behind them I must address. The speaker is a socialist so he despises capitalism (because he doesn't understand it). That is the tone and that is the motivation. So he must attack people who see the great good that freedom in law and in markets (i.e: capitalism) do for people while actually tending towards socialism tends towards severe shortages and lack of growth in both societal and individual health. But let's move onto specifics: 

The speaker (Roland Paulsen) has concerns about what he calls “reality” but by this he means inequality  The concern is completely misplaced. But that’s an anticapitalist, antifreedom socialist for you.

I concede: from the perspective of a continental European, one may well think things are getting worse. In much of *Europe* they are. Also unsurprising for a sociologist to think things are getting bad. In that profession...perhaps.
 
He says means are not reality. He's wrong. Means are reality. He is actually worried about the standard deviation – that is indeed getting bigger. But, and I’ve made this point many times before, inequality could get way worse while everything infact gets way better. Eg: in the distant future the poorest people could be multi billionaires could all own their own islands and get Amazon to deliver stuff by drone, while the richest people ($10^20aires) own entire planets and 3D print literally anything they want…from fusion reactors to food. The inequality will be way way greater than today (when the poorest people have close to zero and the richest are mere billionaires).
 
He says we shouldn't be concerned about the averages anyways - say the average increase in income in a nation because:
 
Income might remain the same (as he says) for 4 decades - but this is silly. A person 4 decades ago isn't earning the same today. But his point is in some places the average doesn't change. But who cares? The people on average income or at the lower level are NOT the same people. And besides: their *quality of life* is far far better. Those people on the same income 40 years ago did not have:
-Access to good medical care
-Smartphones
-The internet and all the world’s information (for goodness sake!)
-CHEAPER food and energy and so on as a percentage of their wage
-Greater mobility. The people at the average or median or even bottom *do not remain there* in capitalism.
-Far more leisure time.

Only under non-capitalist systems are people *condemned to poverty*. Under capitalism people are free to change jobs and create and earn more by working more. Under socialism the more you work has no effect on how much you earn. So his concern about “distributions” is just the usual socialist academic misconception and hatred of wealth. Any amount of “inequality” in income is seen as evil. But as I’ve just explained: everyone might be massively more wealthy than people today but people like that guy will say inequality is evil. Period. But it’s not. Only absolute poverty is – and it’s declininig.
 
People really are not starving like they once were. No one in the USA will ever starve.
 
His stuff on medicine was ridiculous – people are getting healthier and happier. But all such studies that attempt to measure things that cannot possibly be measured (say the nebulous “well being”.). That section is pseudoscientific nonsense. Those happiness indicies are, again, a socialist trope that ask leading questions. It’s not science and gives social science the bad name it has. It’s bad sociology where the answer is known before the questions are asked. They are motivated in their research: they *want* rich nations to be more depressed and poorer nations to be happy. So what questions do they ask? #notscience
 
Extremely dishonest stuff about Mao towards the end. Tries to say that there were some good things about Mao. Now we’re into actual evil. Nothing more worth responding to. 

So does he have a point? Not even half a point, sorry.