an autodidact meets a dilettante…

‘Rise above yourself and grasp the world’ Archimedes – attribution

inference in the development of reason, and a look at intuition

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various more or less feeble attempts to capture intuition 

Many years ago I spent quite a bit of time getting my head around formal logic, filling scads of paper with symbols whose meanings I’ve long since forgotten, obviously through disuse.
I recognise that logic has its uses, tied with mathematics, e.g. in developing algorithms in the field of information technology, inter alia, but I can’t honestly see its use in everyday life, at least not in my own. Yet logic is generally valued as the sine qua non of proper reasoning, as far as I can see.
Again, though, in the ever-expanding and increasingly effective field of cognitive psychology, reason and reasoning as concepts are undergoing massive and valuable re-evaluation. As Hugo Mercier and Dan Sperber argue in The enigma of reason, they have benefitted (always arguably) from being taken out of the hands of logicians and (most) philosophers and examined from an evolutionary and psychological perspective. Charles Darwin read Hume on inference and reasoning and commented in his diary that scientists should consider reason as gradually developed, that’s to say as an evolved trait. So reasoning capacities should be found in other complex social mammals to varying degrees.    

An argument has been put forward that intuition is a process that fits between inference and reason, or that it represents a kind of middle ground between unconscious inference and conscious reasoning. Daniel Kahneman, for example, has postulated three cognitive systems – perception, intuition (system 1 cognition) and reasoning (system 2). Intuition, according to this hypothesis, is the ‘fast’, experience based, rule-of-thumb type of thinking that often gets us into trouble, requiring the slower ‘think again’ evaluation (which is also far from perfect) to come to the rescue. However, Mercier and Sperber argue that intuition is a vague term, defined more by what it lacks than by any defining characteristics. It appears to be a slightly more conscious process of acting or thinking by means of a set of inferences. To use a personal example, I’ve done a lot of cooking over the years, and might reasonably describe myself as an intuitive cook – I know from experience how much of this or that spice to add, how to reduce a sauce, how to create something palatable with limited ingredients and so forth. But this isn’t the product of some kind of intuitive mechanism, rather it’s the product of a set of inferences drawn from trial-and-error experience that is more or less reliable. Mercier and Sperber describe this sense of intuitiveness as a kind of metacognition, or ‘cognition about cognition’, in which we ‘intuit’ that doing this, or thinking that, is ‘about right’, as when we feel or intuit that someone is in a bad mood, or that we left our keys in room x rather than room y. This feeling lies somewhere between consciousness and unconsciousness, and each intuition might vary considerably on that spectrum, and in terms of strength and weakness. Such intuitions are certainly different from perceptions, in that they are feelings we have about something. That is, they belong to us. Perceptions, on the other hand, are largely imposed on us by the world and by our evolved receptivity to its stimuli.

All of this is intended to take us, or maybe just me, on the path towards a greater understanding of conscious reasoning. There’s a long way to go…


The enigma of reason, a new theory of human understanding, by Hugo Mercier and Dan Sperber, 2017

Thinking, fast and slow, by Daniel Kahneman, 2011

Written by stewart henderson

December 4, 2019 at 10:45 pm

What is inference?

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Don’t believe everything you read

What are you inferring?

So am I to infer from this you’re not interested?

What does inferring actually mean? What is it to ‘infer’? Does it require language? Can the birds and the bees do it? We traditionally associate inference with philosophy, which talks of deductive inference. For example, here’s a quote from Blackwell’s dictionary of cognitive science:

Inferences are made when a person (or machine) goes beyond available evidence to form a conclusion. With a deductive inference, this conclusion always follows the stated premises. In other words, if the premises are true, then the conclusion is valid. Studies of human efficiency in deductive inference involves conditional reasoning problems which follow the “if A, then B” format.

So according to this definition, only people, and machines constructed by people, can do it, deductively or otherwise. However, psychologists have pretty thoroughly demolished this view in recent years. In ‘Understanding Inference’, section 2 of their book The enigma of reason, cognitive psychologists Hugo Mercier and Dan Sperber explore our developing view of the concept.

Inference is largely based on experience. Think of Pavlov and his dogs. In his famous experiment he created an inferential association in the dogs’ minds between a bell and dinner. Hearing the bell thus set off salivation in expectation of food. The bell didn’t cause the salivation (or it wasn’t the ultimate cause), the connection was in the mind of the dog. The hearing of the bell set off a basic thought process which brought on the salivation. The dog inferred from experience, manipulated by the experimenter, that food was coming.

Mercier and Sperber approvingly quote David Hume’s common sense ideas about inference and its widespread application. Inference, he recognised, was a much more basic and universal tool than reason, and it was a necessary part of the toolkit of any sentient being. ‘Animals’, he wrote, ‘are not guided in these inferences by reasoning: Neither are children: Neither are the generality of mankind, in their ordinary actions and conclusions. Neither are philosophers themselves, who, in all the active parts of life, are, in the main, the same with the vulgar…. Nature must have provided some other principle, of more ready, and more general use and application; nor can an operation of such immense consequence in life, as that of inferring effects from causes, be trusted to the uncertain process of reasoning and argumentation’.

This is a lovely example of Humean skepticism, which flies in the face of arid logicalism, and recognises that the largely unconscious process of inference, which we would now recognise as a product of evolution, a basic survival mechanism, is more reliable in everyday life than the most brilliantly constructed logical systems.

The point is that we make inferences more or less constantly, and mostly unconsciously. The split-second decisions made in sport, for example, are all made, if not unconsciously, then with an automaticity not attributable to reason. And most of our life is lived with a similar lack of deep reflection, from inference to inference, like every other animal. Inference, then, to quote Mercier and Sperber’s gloss on Hume, is simply ‘the extraction of new information from information already available, whatever the process’. It’s what helps us slip the defender and score a goal in soccer, or prompts us to check the batteries when the remote stops working, or moves us to look forward to break-time when we smell coffee. It’s also what wags your dog’s tail when she hears familiar footsteps approaching the house.

There’s a lot more to be said, of course…

Written by stewart henderson

December 3, 2019 at 9:53 pm

the Palestinian/Israeli tragedy 2 (not so much a timeline)

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found em! Josh’s 12 tribes

It’s been a while since I wrote the first part of this series, and I may never have returned to it but for a book I’ve been perusing, A brief history of the Middle East, by Christopher Catherwood, which has caused some slight irritation. It has also made me feel that my first timeline, which tried to cover the region from about 9000 years ago to the destruction of the second temple by the forces of Titus in the first century CE, didn’t sufficiently cover the religious developments in the region. This is no doubt a product of my secular bias, but since so much of the modern tragedy is wrapped up in religion, I feel I need to at least try to make an effort to make something of the changing religious impulses and beliefs of those more or less prehistoric times. 

Statements in Catherwood’s book have also made this a priority. In its opening chapter, ‘Ancient Empires’, he clearly takes much of the history of the Palestinian region from the Old Testament, which I’ve always assumed to be a highly unreliable historical document (but of course I’m no authority on the region or the period). Particular claims strike me as odd, such as this, on what Catherwood calls the Israelites, or the Children of Israel:

Initially, the new state in which the different tribes settled was a kind of theocratic republic. The people were ruled by prophets speaking on behalf of the one God, a being who the Jews realised was not just a tribal deity, or even simply their tribal deity, but the one and only God who existed.

C Catherwood, A brief history of the Middle East, p19

There’s much that’s problematic here. First, the Jewish movement towards monotheism was a matter of changing belief, not realisation. Realisation here suggests reality, and there’s no evidence that a universal god is any more real than a local, tribal one. This isn’t history. The ‘different tribes’ here refers to the putative tribes of Israel who conquered the promised land. Catherwood assumes that this conquest, and the exodus from Egypt, were real events, even dating the beginning of the conquest at ‘around 1220 BC’ (note the use of the Christian dating scheme, which has long been superseded). You will find voluminous material about the ‘ten (or twelve) lost tribes’ online, but very little, indeed nothing, that amounts to evidence. Much (or should I say all?) of the material is written by Jewish scholars, who spend their lives in disputation over such matters. It’s easy to get swamped by all this. A good place to find a more objective view is, but the likelihood that these Israelites were once enslaved in Egypt is not great – the Egyptians weren’t slave-owners as the later Greeks and Romans were, and there is no evidence of major warfare and ethnic cleansing in the Palestine region at the period Catherwood suggests.

Having said all that, the problem for Palestine is that conservative Jews fervently believe in these myths and in their god-given right to ethnically cleanse all unbelievers and other-believers, in spite of their ancestry in the region.

I’ll take a deep breath and dive into what is known about the religious beliefs and practices during the period when Jewish monotheism became a thing, in future posts on this subject.

Written by stewart henderson

November 25, 2019 at 11:46 pm

reasons to be cheerless, part one…

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Tunguska – caused by an alien

Will anthropogenetic global warming be an unmitigated disaster or will it be a boon to some species, possibly even our own? Will artificial intelligence make slaves of us all or enable us to become masters of the multiverse? Will social media developments turn us all into obese opinionated ignoramuses or will it help to unite the powerless against destructive autocrats? Will virtual reality sex liberate the unattractive or simply diminish real relations? And so on. When considering the future we often make the error of imagining the past as having been more predictable than it was. In particular, we think we know ‘human nature’, and we generally consider it unchanging, so we can predict our response to events, even if we can’t predict the events themselves. IMHO, we’re mistaken even on that count.

But let’s consider an event we definitely can’t control. Maybe there’s an object out there in space, a very big one, that’s on track to smash into our planet, with such speed, power and accuracy, that all concerns about human development and response become superfluous.

Few things can be more chilling than inevitability. I experienced this once in my early twenties, in casual conversation with a friend. Something in our talk struck me, and I realised, in a heart-freezing moment, that I was destined to die. Of course, I’ve had a long time since then to come to terms with it! But in reading of fatal events, what often torments the mind is the gap between the knowing and the happening. As they say, falling off a cliff never hurt anyone, it’s the landing that does it – but that’s probably wrong, you can suffer a lot of hurt in anticipating the end.

So this morning I was reading about Shoemaker-Levy 9, a comet named after those who discovered it, more or less by accident (though it was the ninth comet discovered by the team, hence the name), in 1993, by which time it had been captured by the gravitational field of Jupiter. In fact, studies of its orbital motion showed that it had been orbiting Jupiter for at least twenty years, and had begun to fragment a year or so before its discovery, when it passed close to Jupiter in an eccentric orbit. It was the first comet ever discovered to be orbiting a planet rather than the sun. Its discovery caused a sensation in the astronomical community, especially as further calculations of its behaviour confirmed that it was certain to collide with the planet. Which, in one week in July 1994, it spectacularly did, in bits and pieces, the largest of which had an impact described at the time as ‘500 times more powerful than the detonation of the whole world’s nuclear weaponry’.

Jupiter is, of course, the largest planet in our solar system, and has been described as a ‘cosmic vacuum cleaner’, sucking asteroids and small comets into its orbit at a rate many thousands of times more than Earth does. The assumption being that it’s protecting us little planets from a lot of nasty stuff. And yet…

great pic of Comet Hyakutake, in 1996

That protection isn’t guaranteed, as what is now called the Cretaceous-Palaeogene impact even shows. That was pretty massive, and the Tunguska event of 1908 was relatively tiny, as was the Chelyabinsk event of 2013, and then there are much larger bodies passing by, such as Comet Hyakutake, and so on. But as to the size and placement of these events, we seem not to reliably forewarned. The second largest impact in over 100 years (since Tunguska) occurred in December 2018, but few lay people even know about it. It occurred over the Bering Sea, between Russia and Alaska. The meteor had a diameter of 10 metres – nothing compared to Shoemaker-Levey 9’s five kilometre nucleus – and of course it impacted in a region uninhabited by humans, but the fact that these impacts aren’t picked up until the last minute is a worry. Of course technology is being developed to improve the situation, but it’s not there yet. And then there’s that mighty, faraway object that might be hurtling towards us, beyond our ken…

Written by stewart henderson

November 24, 2019 at 12:00 pm

Laws are more important than constitutions, get it?

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not entirely relevant to this piece, but worth considering…

Watching proceedings from afar against Trump and his blundering bovver boys, I become more agitated than I probably need to, but I quite often find my frustration directed more at the prosecutors than at Trump’s mostly contemptible allies. For example, MSNBC commentators and many of their guests, not to mention Nancy Pelosi, are still claiming that the crime here is bribery, when it’s clearly extortion, which is generally considered a more serious crime.

So what’s the difference? It should be obvious. A bribe generally involves appealing to a person’s venality. It’s usually presented in positive terms, as in ‘I’ll make you rich beyond the dreams of avarice if you just do this dirty job for me’. Extortion however is presented in more menacingly negative terms – ‘if you don’t do this dirty job for me, you’ll really really regret it’. Now, it’s notable that the infamous phone call from Trump was relatively polite, which is why he’s trying to characterise it as ‘perfect’. After all, by his boorishly bullying standards, it probably was. The near-polite asking of a favour, then, might be characterised as a bribe, but what was happening behind the scenes, directed by Trump, was definitely extortionate. That’s why focussing on the phone call as the main incident is definitely a mistake, and that’s why Giuliani, Mulvaney and Trump himself need to testify, and should of course be made to, and jailed immediately if they refuse, as should happen in any nation worthy of respect.

But this would only happen if the matter was being dealt with in court – where of course it should be dealt with.

Americans are profoundly worshipful of their constitution and their founding fathers. Indeed they seem to have been fine, upstanding, as well as colourful fellows. It’s my view, though, that given current circumstances, they’d have been the first to realise that the constitutional provisions for dealing with a law-breaking, rogue President were wholly inadequate. This isn’t surprising – experience is the best teacher in these matters, and the US experience has been mostly of Presidents priding themselves on being ‘gentlemen’. This is the only silver lining of this presidency, that it has exposed manifold inadequacies of the constitutional presidency system. 

Constitutions are guides to how governments are to be constituted. I don’t think the framers of this or any other constitution ever imagined that later followers would expect that it constituted the entire law under which the head of state operated. That, to me, is virtually proven by the vague and minimalist treatment of the legal liabilities of the President in the US Constitution. Surely the founding fathers took it for granted that the President would be subject to all the laws of the land that any other citizen would be subject to. How could it be otherwise for someone in leadership, someone expected to set an example? Even minor infractions would be seen as ‘the thin end of the wedge’, and generally this is the case under the Westminster system. 

The worst argument that could possibly be given for the kind of immunity granted to the US President is that he’s too powerful to be charged with a crime. You might call this the Putin argument (or the Stalin, Ghengis Khan or Ramses II argument, or name your favourite dictator). The argument hasn’t improved over the last 3000 years. 

Written by stewart henderson

November 21, 2019 at 4:32 pm

sauropod dreaming

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a bunch of sauropods caught not eating


African bush elephants are today’s largest land animals. The heavier males weigh about 8 or 9 short tons on average. Ridiculously, heavy stuff can nowadays be measured in short tons (US), long tons (British) and metric tons, or tonnes. Come on scientists, instil some discipline here.

Many sauropod (meaning ‘lizard-footed’) dinosaurs were much heavier, though there’s much disagreement about actual weight, regardless of measurement methods. The semi-legendary Bruhathkayosaurus has been described as weighing some 120 tons (of some kind). If this is anywhere near correct, how did such beasts, notable for their long necks and tails, manage to carry themselves around with any sort of grace or agility over millions of years?

Brian Ford, in his recent book Too big to walk, argues that they must have been aquatic or semi-aquatic, a minority view that dates back to the 19th century.

Sauropods were herbivorous quadrupeds, the earliest known of which, Antetonitrus, dates from the Norian Age of the Upper Triassic, somewhere around 220 mya, and the last of which, the real titanosaurs, lived for some 70 million years (not individually) before the Cretaceous–Paleogene extinction event which brought the dinosaur age to an end. Clearly, these were very successful beasties in their day, but how did they manage to feed themselves to sustain their enormous weight, and to provide the enormous energy required to shift that weight around? These and many other sauropody questions have been the subject of lively debate in recent decades, raising questions of habitat and habits as well as anatomy, physiology, metabolism, circulation, respiration, nutrition, organic function and so on. For example, it’s estimated that a sauropod weighing ten times as much as an elephant (which spends about 80% of its waking life foraging) would require about 100,000 calories a day, or about 450 kilos of foliage. They probably swallowed this stuff whole, and relied on micro-organisms in their massive guts to break it all down. Of course, much of what we think we know of these creatures is speculative.

So what do we think we know about their environment, and how they negotiated it? Presumably, that environment wasn’t stable over 140 million years, and over the whole range of sauropod fossil discoveries. Early representations often placed them in aquatic environments, but in the late 20th century the consensus view that their bodies were ‘permeated with air-sacs’ required a shift of perspective, which I can’t easily follow. It seems the air-sacs would have, in effect, caused them to be totally buoyant and unstable in deep water, due to their maladaptive body proportions. However, sauropod fossils have often been found mingled with those of marine organisms, and their footprints have often been associated with floodplains and lagoons. 

There’s a lot still to learn about how they moved and sustained themselves. Could they rear up on hind legs, supported, kangaroo-style, by their massive tails (a ‘tripodal stance’)? Often they’re depicted in museums and paintings in unusual stances and poses, more for visual effect than to capture a known reality. There’s some evidence that the very elongated Diplodocids, which had a lower centre of mass, were well adapted for the tripodal stance, unlike other titanosaurs. 

Clearly there’s far more that we don’t know about dinos large and small, than what we know, and we’re living at a time of abundant fossil discoveries. It all makes for entertaining reading. 


Too big to walk: the new science of dinosaurs, by Brian Ford, 2018

Written by stewart henderson

November 19, 2019 at 4:22 pm

pardonnez-moi, mais c’est ridicule

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Today I heard the American legal expert and editor of Lawfare, Ben Wittes, assuring a cable news host that the President had an absolute right, or ‘ability’, to pardon anyone he wishes. This came up in a discussion of the Roger Stone guilty verdict recently handed down.

Of course I noted that there was no sign of shame or embarrassment in Wittes’ pronouncement, which I will take on trust to be true. Nor did I expect to observe such a sign. I’ve become ‘Americanised’ to a certain degree in the past couple of years. But I also feel a need to resist this.

As has been noted by many people, Stone has been a close personal friend and associate of Trump for many decades. So, will he pardon Stone?

To be asked to enter the mind of the current US President, on this or any other matter, would be the ultimate ‘hardship assignment’, but still it’s interesting to speculate why he may hesitate to pardon Stone. First, Stone is no longer of any use to him – and that is generally Trump’s foremost consideration. Second, Trump is conscious, however vaguely, of going ‘too far’ in certain directions, though he sometimes errs on this front. Third, he appears to be a creature of the ‘eternal present’, in which case his failure to pardon Stone would be due to indifference rather than hesitation. His new ‘buddies’ are – or possibly were – the three amigos, and so it goes.

But to return to the Presidential pardoning powers – it seems to take an outsider to note how totally outrageous and immoral they are. A pardoning power, granted, is an important power for a government to have, but within very strict limitations. In Australia the power is vested in the Governor-General, the Queen’s representative, but of course he or she is instructed by the government of the day, through the principal law officer, the Attorney-General, in consultation with the rest of government. It’s a rarely used power in Westminster-style governments, as it should be. A notable recent example of its use is the so-called ‘Alan Turing Law’, which pardoned thousands of gay men, living and dead, who have been prosecuted over decades for behaviour now deemed legal. However, in the US the Presidential pardoning power has often been abused, as in the case of Richard Nixon (not sufficiently condemned), and more recently by Donald Trump’s pardoning of Libby and Arpaio. The general US population has been troublingly insouciant about this power. To have it vested in one person (there is an ‘Office of the Pardon Attorney’ but I doubt that Trump recognises or has even heard of it) is of course typical of that superhero-worshipping nation, but it’s another failure of a system that Trump will surely be seeking to exploit in his battle to secure ultimate dictatorship.

Meanwhile, there are always new developments in the runaway trainride of this current presidency. A new name, David Holmes, may have entered the lists of history, in a small way. Of course all of these names – the names of people who actually work hard for their nation and for positive international relations – deserve to remembered better than the current US President, but life never was fair.

Written by stewart henderson

November 17, 2019 at 4:21 pm

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