Crabsallover blog: 18 Feb 2007

Sunday, February 18, 2007

Why do placebos work?

Tor Wager makes his living inflicting pain. As a psychologist at Columbia University, he zaps people with brief electric surges in order to study the placebo effect, one of the most mysterious phenomena in modern medicine. In one recent experiment, Wager and a group of colleagues delivered harsh shocks to the wrists of 24 test subjects. Then the researchers rubbed an inert cream on the subjects’ wrists but told them it contained an analgesic. When the scientists delivered the next set of shocks, eight of the subjects reported experiencing significantly less pain.

The idea that an innocuous lotion could ease the agony of an electric shock seems remarkable. Yet placebos can be as powerful as the best modern medicine. Studies show that between 30 and 40 percent of patients report feeling better after taking dummy pills for conditions ranging from depression to high blood pressure to Parkinson’s. Even sham surgery can work marvels. In a recent study, doctors at Houston’s Veterans Affairs Medical Center performed arthroscopic knee surgery on one group of patients with arthritis, scraping and rinsing their knee joints. On another group, the doctors made small cuts in the patients’ knees to mimic the incisions of a real operation and then bandaged them up. The pain relief reported by the two groups was identical. “As far as I know, the placebo effect has never raised the dead,” says Howard Brody, a professor at the University of Texas Medical Branch and author of a book on the subject. “But the vast majority of medical conditions respond to placebo at least to some degree.”

How do placebos have such an effect? Nobody knows. Studies have shown that our brains can release chemicals that mimic the activity of morphine when we’re treated with placebo analgesics. But only lately have researchers begun to pin down the underlying physiological mechanisms. In his groundbreaking electrical-shock experiment, Wager used functional MRI to examine images of the brain activity of his subjects. When a person knew a painful stimulus was imminent, the brain lit up in the prefrontal cortex, the region used for high-level thinking. When the researchers applied the placebo cream, the prefrontal cortex lit up even brighter, suggesting the subject might be anticipating relief. Then, when the shock came, patients showed decreased activity in areas of the brain where many pain-sensitive neurons lead.

One day, this sort of research could point toward new treatments that harness the mind to help the body. Until then, doctors are divided on the ethics of knowingly prescribing placebos. Some think it’s shady to perform mock surgery or offer a patient pills that contain no active ingredients. Yet the best doctors have always employed one form of placebo: Studies show that empathy from an authoritative yet caring physician can be deeply therapeutic. Maybe handing out the occasional sugar pill isn’t such a bad idea.

Shannon Brownlee, senior fellow at the New America Foundation

Return to Big Questions: http://www.wired.com/42

There is an argument that the placebo effect works because there is an evolutionary advantage in our ability to respond to treatment (no matter what), but I think that one thing worth considering is the fact that medication very often represents treatment by others.

Perhaps as social organisms our awareness of being valued by others is reason in itself to respond to placebos. This could be the case when we are provided with medication by another person (representing to us our value or worth to others) or in the case of an ill person with dependents, self administration would be symbolic of the dependents' need for the ill person. In either case the medication or treatment becomes a token of social status and worth.

By this reading the placebo effect could be explained as part of the same spectrum of phenomena that includes at one end very ill people's apparent capacity to live long enough to see important events in their lives (births, marriages etc.) and at the other end the clearly detrimental effects of treatments representing low worth (e.g. solitary confinement.)

Autism is (as I understand it) the inability to read social cues. If that is the case it may be worth investigating whether autistic people have a relatively diminished response to placebos...

http://entrepot.blogspot.com/

contributed by Guest User on Jan 24 4:19pm

In Chinese medicine, the mind itself is a vital substance in the body. They call this substance "Shen" and consider it a major player in disease and healing processes. It is not merely an esoteric or spiritual component, but an aspect of physiologic function that is deeply integrated with the blood and body structures. From this vantage point, activating the mind means activating physiologic function.

There's great flurry in neurology regarding the search for memory - how exactly do we store and process memory? Yes, we can locate specific filing locales in the brain, but that alone is insufficient to explain all facets of memory. Many believe and seek to prove that memory is stored in every cell in the body, somehow regenerated and/or lost as cells regenerate and function. Western science has also had a lot of fun discovering levels of communication between organ systems and the brain, pathways we once assumed were unidirectional now reveal sophisticated two-way dialogues. The digestive system and the heart each send independent messages to the brain and "make decisions" on their own. There is more to the way we function than just a brain running the show. That's like saying the CPU and motherboard in my laptop are typing these vowels and consonants, turning them into words, phrases and concepts.

The mind is not the brain. It is what runs the brain, and the entire body. It is substantial and esoteric simultaneously and we brain-thinkers tend to stop short of understanding what the mind truly is. If two elementary cells can differentiate into the complex organs, materials and personality of a human being, why not believe that the mind in charge of the body has the capacity to rewrite any program it chooses? Pain can be overcome by thought. Pain can be caused by thought. Why not?

Laurie Perez, L.Ac
http://www.xincare.com

contributed by Laurie Perez on Feb 6 9:51am

Most placebos have an apparent 'effect' in diseases or conditions in which subjective perception is known to make a difference. Our perception of pain is well known to be influenced by both psychological and socio-cultural factors. We interpret the effects of these influences as the powerful involvement or our minds on our somatic selves.

Where the so-called placebo effect fails to manifest itself is in diseases with more concrete biological origins. Take cancer, for instance. As scientists, we study the therapeutic effects or our high-tech, genomic research derived biological treatments, often comparing them to placebo. We express our results as either worse, the same or, hopefully, better than placebo. Looking at historical data on cancer outcomes, we easily conclude that the placebo effect is no different than the natural outcome of that particular cancer. While the 30 or 40% placebo 'effect' is often seen when the placebo is compared to a real treatment (ie 30% of participants treated with placebo report improved fill in the blank vs x% with study medication) . Placebo vs nothing has no effect in cancer. In other words, while pain may be modulated by whatever you want to define as the 'mind', cancer, and other biological diseases are not subject to these influences. Sure there are case reports and anecdotal evidence of cancers getting 'better' because of this or that belief, but these are very poorly documented, studied and entirely irreproducible.

We've cloned the entire human genome, we are in the process of systematically decoding its secrets. We are at the dawn of a quantum leap in our understanding of human physiology and disease. But just because there is still so much modern science does not understand, does not mean that we should jump to conclude that antiquated theories of 'vital substances' should rush in to fill those lacunes.

Michael Sebag, MD, PhD.

The point of mentioning Shen and mind as a vital substance was to describe the perception of Chinese medicine on how placebo might work, not to negate the merits of genomic discovery. Contrary to popular misconceptions, Chinese medicine does not rely on thought or belief for treatment; it relies on physical therapies, internal medicine and lifestyle / nutritional regulation. In other words, it is equally focused on the physical body and its biology.

The CM theory of how the mind plays a role in physiology may belong to a very old medical paradigm, but it's not actually outdated or in conflict with the discoveries of the current era. It may simply hold one of those keys to decoding a mystery as intriguing as the placebo effect.

Laurie Perez, L.Ac
http://www.xincare.com

contributed by Laurie Perez on Feb 6 2:24pm

I agree, the theory of 'vital substances' to explain physiological responses does not in any way negate the merits of genomic research. What it does, however, is somewhat more nefarious, as it attempts to comprehensively fill in the gaps that lie beyond the leading edge of our research endeavours. While I agree that there are merits in Chinese traditional medicine, much of it remains unexplained, incomprehensible and irreproducible in scientific settings. Centuries of practice has led to an empiric knowledge of the effects of certain herbs, roots, tree barks and preparations. The biochemistry, pharmacology and physiology needed to understand these effects are only now being applied to the study of tranditional Chinese medicine. A quick look at scientific publications on a variety of traditional Chinese therapies reveals that these may have specific reproducible biochemical properties. Not all of them work, but some do. Those that do, likely do not rely on a placebo effect.

As a society, we spend an exceedingly large amount money on the exploitation of the 'placebo' effect. Many 'alternative' therapies are at best, unproven, although I admit that they may 'stimulate' the placebo effect. The problem is that as placebos, 'alternative' therapies are expensive. We have turned down too many cancer patients that could benefit from our newly discovered biological therapies. These new targeted therapies cost, sometimes unjustifiably, a fortune and we are running out of money. Why waste so much of our precious health-care dollars on expensive placebos?

contributed by Michael Sebag on Feb 6 3:42pm

In my opinion, the theory of 'vital substances' should be understood in a way similar to our understanding of the theory of the 'atom'. There is no 'atom' as the term was originally meant -- an indivisible particle. Go down far enough, and everything is patterns of energy. The word 'atom' remains useful as a signifier in the context of our ongoing work in physics, and our definition and understandings of 'atoms' continue to expand. Similarly, the Chinese Medical theory of 'vital substances' is useful within the context of CM practice. We may never find a physical entity we could call 'shen' (or 'chi' or 'jing', to name the other two vital substances). The meaning of 'substance' in the phrase 'vital substance' has never meant a visually observable physical entity, however. A better translation of 'substance' into the terminology of modern science might be 'perceptible web of causation in the body'.

This concept of a web of causation, where everything is a dependent variable of everything else, is the essence of Chinese Medical theory. It is also something that modern science is still struggling to come to grips with. It is clear that biological systems are immense webs of nested and inter-locking feedback loops; nonetheless, most biomedical research is done using traditional experiment structures attempting to isolate a the behavior of a dependent variable.

In looking at the effects we call 'placebo', it might be useful to investigate the patterns that produce these 'placebo' effects -- or the 'spontaneous remissions' that happen in some cases where no 'placebo' application has been recorded. The words 'placebo' and 'spontaneous remission' both remove our attention from what has happened: a person got well through a mechanism we do not currently understand. The various systems of our bodies, coordinated through a wide range of information transfer mechanisms, continuously maintain our well-being. For example, most cancers are eliminated by the immune system before they are detected by any sort of medical system. Biomedicine has given up on the ancient Greek theories of 'vital substances', and for good reasons. Unfortunately, we now lack terminology and a philosophy of experimental inquiry that would allow us to easily investigate the aspects of the human system that make us whole. (There are numerous inroads being made of course -- the work of neuroendocrinologists such as Candace Pert, and the heart-brain-body interactions described as 'physiological coherence' by the HeartMath Institute researchers are two examples).

Whether we use (and redefine through research) Chinese words like 'shen' to represent the information patterns within the body that make us whole, use and redefine English words like 'spirit' and 'integrity', or we invent new words that better suit our modern sensibilities, we will undoubtedly require such a concept to understand the way in which people become well.

Nathaniel White
contributed by Nathaniel White on 2007-02-09 12:05 GMT

reposted from: http://www.eu.socialtext.net/wired-mag/index.cgi?why_do_placebos_work
my highlights / emphasis / comments

What do scientists mean by 'theory'?

Posted on: February 10, 2007 3:33 PM, by Janet D. Stemwedel

In my basic concepts post on theory testing, I set out what I take to be a fairly standard understanding of "theory" in philosophy of science discussions:

... a theory is a group of hypotheses that make claims about what kind of entities there are and how those entities change over time and interact with each other. If you like, the theory contains claims about ontology and laws. If you prefer, the theory tells you what kind of stuff there is and how that stuff behaves.

In a comment, Lab Lemming opined:

That's a really odd way to think of theories. I reckon a theory is something that is both sufficiently broad and sufficiently tested that a scientist can use it to figure out how to frame a question in a testable manner.
For example, if you're looking into an outbreak of a drug resistant germ, you can use the theory of evolution to design an experiment that will test how this resistance arose, and how effective it is against other drugs.

Now, I don't think these two descriptions of a theory are necessarily contradictory, although the theory-as-set-of-hypotheses I'm describing might not be well tested (i.e., it could be a new theory). Indeed, it seems like having some picture of what kind of stuff you're dealing with and some of the ways that stuff behaves it at least extremely helpful, if not absolutely necessary, to the framing of questions in a testable manner.

The thing that interests me here is the possibility that scientists think of "theory" in a different way than the philosophers of science who are trying to make sense of what scientists are doing. So, a question to the scientists: How would you define (or at least describe) a theory? If you think it's relevant (and it may well be), indicate your scientific field.

Once we have some "empirical data" on this, I'll give you my hunches as to what may be behind some of the differences in perspective.

Comments

Here was my take from a while back:

http://cosmicvariance.com/2005/09/19/theories-laws-facts/

Basically, if what you care about is how scientists use the word theory, rather than some prescriptive notion of how it should be used, you have to face up to the fact that the usages are wildly varying and inconsistent. Sometimes it just means "a model," other times it means "a subject area," other times it means "a well established set of rules and ideas." I worry about pretending that it means something more specific and well-defined than it really does.

Posted by: Sean Carroll | February 10, 2007 04:55 PM

As a follow-up, here is some empirical data, in the form of papers in the SPIRES high-energy physics database that use the word "theory" in the title:

http://www.slac.stanford.edu/cgi-bin/spiface/find/hep/www?rawcmd=t%20theory&FORMAT=WWW

It's easy to see all of the above meanings, plus several more.

Posted by: Sean Carroll | February 10, 2007 04:59 PM

As a theorist (of soft matter; polymers and the like), I think an important element of a theory is that it is a (somewhat) comprehensive model of a class of phenomena. An equation is not, by itself, a theory. A prediction is not, by itself, a theory. In order to qualify as a theory, a model has to provide an explanation for some already-observed phenomenology and a prediction for some other (already observed, or capable of being observed, at least technically) phenomenology. Your definition makes sense, but it's not really how I would think of a theory while in the process of developing one.

Posted by: Capella | February 11, 2007 12:56 AM

I tend to regard science as an excercise in building (and testing) explanatory links between disparate observations and data; so I think of a theory as the description of all the links between a particular set of data, as well as an assessment of how well-supported those links are (tested to death, seemingly well-supported, speculative).

I'd guess Lemming is just making the point that theories are not solely an end in themselves, but that they are also used as tools - people use the present pattern of links to propose new connections, or transplant them into new fields.

Posted by: gengar | February 11, 2007 06:10 AM

I take back the well-tested requirement for theories.

Or, rather, I admit that it was a value judgement on my part- that I think that scientists are generally better off using those sorts of theories.

As Sean points out in his blog, some theories, like phlogiston, or lamarkian evolution, don't hold up very well at all. So there are good theories and bad theories.

However, I don't think you can tell the difference between them by any sort of logical proof or analysis. I think the most appropriate way to evaluate theories is on the basis of their utility. There are useful theories, and theories that are a waste of time. And judging theories by their utility gives us a handy way to differentiate science from philosophy, logic or religion, which deal in non-scientific matters like truth and correctness.

I have a half-baked explanation of how this applies to evolution written somewhere, which I'll try to find, finish, and post.

Posted by: Lab Lemming | February 11, 2007 06:30 AM

I'm in comparative religions... do social scientists count?

We use theory to focus in on the giant pile of data in our field, to tease out specific elements we want to examine. It's a necessary tool for methodological reduction.

Posted by: John B | February 11, 2007 08:32 AM

To me a theory is a set of experiments incorporated into a story which lets you make predictions about experiments to come. Thus you have a theory in your head, and in that framework you construct hypotheses which you can test.

I think a lot of divergence comes in the barriers you set yourself in how you can tell stories from a theory, and what the relevant objects are (if you're worrying about binary effects of having genes, the structure looks rather different than if you're fighting with the 23rd decimal place of a measurement of a physical constant).

Posted by: Frederick Ross | February 11, 2007 09:40 AM

I agree with Sean, that the problem is that theory has several, closely related, meanings in science. I think you need a lexicographer to tease out these meanings.

Bob

Posted by: Bob O'H | February 11, 2007 11:24 AM

We don't need no stinkin' lexicographer!

That is to say: What I'm really asking for is not the officially way Science defines Theory. Rather, I'm interested in how actual scientists in various scientific fields and contexts use the word theory. (Lexicographers need to attend to usage, I reckon.) So, I'm under no illusion that all the things people mean by "theory", or expect should come along with a "thoery", or would identify in contrast to "theory" will line up neatly.

I just want some good reports from the field, as it were.

Posted by: Janet D. Stemwedel | February 11, 2007 02:32 PM

I tend to think of a theory first as a system for establishing correspondences between the terms and operators of some formalism on the one hand, and objects, processes, and relationships of phenomena in the world on the other hand. That is, theories are interpretations of formalisms.

Testing theories then resides in messing with the transition rules of the formalism to generate predictions of what will happen if the corresponding objects, processes, and relationships are altered in a similar way. For example, interpreted in terms of objects and operations performed on them, F=MA suggests that if I pare some M off an object and accelerate it, measured F will be a specified amount less than it was before I did the paring at the same acceleration. Lots of tests tend to more strongly corroborate the theory (formalism plus correspondence rules).

The formalism doesn't necessarily have to be expressed in explicit equations. I do applied work with evolutionary algorithms -- simulations -- and theory tells me about correspondences between the processes in the model running in the computer and the phenomena of interest in complex adaptive systems. Multiple runs of the simulators under plausible perturbations provide ranges of outcomes to be expected in the world of phenomena we model, and the veridicality of those predicted outcomes are tested with real money every day in various derivatives markets. Trading in negative-sum markets is much less forgiving of invalid or plain wrong theories than are one's (former) academic colleagues. :)

Posted by: RBH | February 11, 2007 06:46 PM

Lexicographers need to attend to usage, I reckon.

I was assuming they did! At least the approach the OED takes is descriptive - i.e. they describe the way words are used. I agree that having a prescriptive lexigographer involved would be awful.

I think a survey of usage would be useful, and may have been done. But searching lexicographal journals for "theory" and "science" may not be the wisest way of finding it.

Bob

Posted by: Bob O'H | February 14, 2007 03:09 AM

My $.02 worth on this topic:

Science starts with an observation. You devise a hypothesis to explain the observation. Then you use the hypothesis to make predictions. Then you test the predictions. If the predictions are wrong, then you go back and try a different hypothesis. If the predictions are correct, you try to expand the hypothesis to be more general and more powerful. A very general, very complex hypothesis that makes lots of verifiable predictions and explains lots of different observations is called a theory.

I still call things like phlogiston and Ptolemaic astronomy by the term "theory" because they were well-meant attempts to form theories, using the best evidence then available. They failed because they didn't agree with the facts, not because they were internally flawed or illogical.

Posted by: wolfwalker | February 14, 2007 08:12 AM

Action plan for killer asteroids

By Jonathan Fildes
Science and technology reporter, BBC News, San Francisco

Nasa is tracking many asteroids

A draft UN treaty to determine what would have to be done if a giant asteroid was on a collision course with Earth is to be drawn up this year.

The document would set out global policies including who should be in charge of plans to deflect any object.

It is the brainchild of the Association of Space Explorers, a professional body for astronauts and cosmonauts.

At the moment, Nasa is monitoring 127 near-Earth objects (NEO) that have a possibility of hitting the Earth.

The association has asked a group of scientists, lawyers, diplomats and insurance experts to draw up the recommendations.

The group will have its first meeting in Strasbourg in May this year. It is hoped the final document will be presented to the UN in 2009.

"We believe there needs to be a decision process spelled out and adopted by the United Nations," said Dr Russell Schweickart, one of the Apollo 9 astronauts and founder of the Association of Space Explorers.

Known threat

The threat of an asteroid hitting the Earth is being taken more and more seriously as more and more NEOs are found.

In the US, Congress has charged Nasa with the task of starting a more detailed search for life-threatening space rocks.

"Congress has said that Nasa's efforts to date are not sufficient to the threat," said the US space agency's Dr Steven Chesley.

"They have changed Nasa's targets so that the cataloguing and tracking of asteroids is part of its mandate."

Congress has asked the agency to mount a much more aggressive survey.

At the moment, Nasa tracks all objects greater than 700m (2,300ft) in diameter. The agency's new goal is to track all objects greater than 70m (230ft) in diameter.

To do this, the agency needs to use a new suite of telescopes.

Alternatives include building a new Nasa-owned system or investing in other proposed telescopes such as the Large Synoptic Survey Telescope (LSST) or the Panoramic Survey Telescope & Rapid Response System (Pan-Starrs).

Pan-Starrs is a wide-field telescope being developed at the University of Hawaii, whilst the LSST is a proposed ground-based instrument being developed by the not-for-profit LSST corporation based in the US.

Nasa estimates that there are about 20,000 potentially threatening asteroids yet to be discovered.

"Out of those thousands, there will be without question many that look like they might hit the Earth with a high enough probability that the public and everyone else will be concerned," said Dr Schweickart.

"This has gone from being an esoteric statistical argument to talking about real events," added Dr David Morrison, an astronomer at the Nasa's Ames Research Center.

Future plans

The UN draft treaty would establish who should be in charge in the event of an asteroid heading towards Earth, who would pay for relief efforts and the policies that should be adopted.

In addition, it would set out possible plans to deflect the object.

Ideas could include hitting the asteroid with a spacecraft or rocket to deflect its orbit.

Other less destructive proposals include a "gravity tug" that would simply hover over the asteroid and use gravity as a "towline" to change its path.

But any decision to deflect an NEO could come with its own set of conundrums for the UN, as changing its path may simply alter its final target.

"It's important to understand when you start to deflect an asteroid that certain countries are going to have accept an increase in risk to their populations in order to take the risk to zero for everyone," said Dr Schweickart.

It is difficult decisions like this which can only be addressed by the UN, the Association of Space Explorers believes.

And it is under no illusion that the process can be sorted out quickly.

"You have to act when things look like they are going to happen - if you wait until you know for certain, it's too late," said Dr Schweickart.

Experts who will draw up the treaty include Lord Rees, the English Astronomer Royal and head of the Royal Society; the ex-director of science at the European Space Agency, Roger Bonnet; and former UK government advisor Sir Crispin Tickell.

The proposals were outlined at the American Association for the Advancement of Science (AAAS) annual meeting in San Francisco, US.

reposted from: http://news.bbc.co.uk/1/hi/sci/tech/6370817.stm
my highlights / emphasis / comments

Karl Popper - contribution to Scientific Method

Sir Karl Raimund Popper is counted among the most influential philosophers of science of the 20th century (also wrote extensively on social and political philosophy - not included here). Popper is perhaps best known for repudiating the classical observationalist-inductivist account of scientific method by advancing empirical falsifiability as the criterion for distinguishing scientific theory from non-science.

In 1934 he published his first book, Logik der Forschung (The Logic of Scientific Discovery), in which he criticised psychologism, naturalism, inductionism, and logical positivism, and put forth his theory of potential falsifiability being the criterion for what should be considered science.

Philosophy of Science

Popper coined the term critical rationalism to describe his philosophy. The term indicates his rejection of classical empiricism, and of the observationalist-inductivist account of science that had grown out of it. Popper argued strongly against the latter, holding that scientific theories are universal in nature, and can be tested only indirectly, by reference to their implications. He also held that scientific theory, and human knowledge generally, is irreducibly conjectural or hypothetical, and is generated by the creative imagination in order to solve problems that have arisen in specific historico-cultural settings. Logically, no number of positive outcomes at the level of experimental testing can confirm a scientific theory, but a single counterexample is logically decisive: it shows the theory, from which the implication is derived, to be false. Popper's account of the logical asymmetry between verification and falsification lies at the heart of his philosophy of science. It also inspired him to take falsifiability as his criterion of demarcation between what is and is not genuinely scientific: a theory should be considered scientific if and only if it is falsifiable. This led him to attack the claims of both psychoanalysis and contemporary Marxism to scientific status, on the basis that the theories enshrined by them are not falsifiable.

Popper also wrote extensively against the famous Copenhagen interpretation of quantum mechanics. He strongly disagreed with Niels Bohr's instrumentalism and supported Albert Einstein's realist approach to scientific theories about the universe. Popper's falsificationism resembles Charles Peirce's fallibilism. In Of Clocks and Clouds (1966), Popper said he wished he had known of Peirce's work earlier.

In All Life is Problem Solving, Popper sought to explain the apparent progress of scientific knowledge—how it is that our understanding of the universe seems to improve over time. This problem arises from his position that the truth content of our theories, even the best of them, cannot be verified by scientific testing, but can only be falsified. If so, then how is it that the growth of science appears to result in a growth in knowledge? In Popper's view, the advance of scientific knowledge is an evolutionary process characterised by his formula:

$PS_1 \rightarrow TT_1 \rightarrow EE_1 \rightarrow PS_2$

In response to a given problem situation ( $P S 1$ ), a number of competing conjectures, or tentative theories ( $T T$ ), are systematically subjected to the most rigorous attempts at falsification possible. This process, error elimination ( $E E$ ), performs a similar function for science that natural selection performs for biological evolution. Theories that better survive the process of refutation are not more true, but rather, more "fit"—in other words, more applicable to the problem situation at hand ( $P S 1$ ). Consequently, just as a species' "biological fit" does not predict continued survival, neither does rigorous testing protect a scientific theory from refutation in the future. Yet, as it appears that the engine of biological evolution has produced, over time, adaptive traits equipped to deal with more and more complex problems of survival, likewise, the evolution of theories through the scientific method may, in Popper's view, reflect a certain type of progress: toward more and more interesting problems ( $P S 2$ ). For Popper, it is in the interplay between the tentative theories (conjectures) and error elimination (refutation) that scientific knowledge advances toward greater and greater problems; in a process very much akin to the interplay between genetic variation and natural selection.

Where does "truth" fit into all this? As early as 1934 Popper wrote of the search for truth as one of the "strongest motives for scientific discovery." Still, he describes in Objective Knowledge (1972) early concerns about the much-criticised notion of truth as correspondence. Then came the semantic theory of truth formulated by the logician Alfred Tarski. (Its first published form was in 1933.) Popper writes of learning in 1935 of the consequences of Tarski's theory, to his intense joy. The theory met critical objections to truth as correspondence and thereby rehabilitated it. The theory also seemed to Popper to support metaphysical realism and the regulative idea of a search for truth.

Critics

The Quine-Duhem thesis argues that it's impossible to test a single hypothesis on its own, since each one comes as part of an environment of theories. Thus we can only say that the whole package of relevant theories has been collectively falsified, but cannot conclusively say which element of the package must be replaced. An example of this is given by the discovery of the planet Neptune: when the motion of Uranus was found not to match the predictions of Newton's laws, the theory "There are seven planets in the solar system" was rejected, and not Newton's laws themselves. Popper discussed this critique of naïve falsificationism in Chapters 3 & 4 of The Logic of Scientific Discovery. For Popper, theories are accepted or rejected via a sort of 'natural selection'. Theories that say more about the way things appear are to be preferred over those that do not; the more generally applicable a theory is, the greater its value. Thus Newton’s laws, with their wide general application, are to be preferred over the much more specific “the solar system has seven planets”.

Thomas Kuhn’s influential book The Structure of Scientific Revolutions argued that scientists work in a series of paradigms, and found little evidence of scientists actually following a falsificationist methodology. Popper's student Imre Lakatos attempted to reconcile Kuhn’s work with falsificationism by arguing that science progresses by the falsification of research programs rather than the more specific universal statements of naïve falsificationism. Another of Popper’s students Paul Feyerabend ultimately rejected any prescriptive methodology, and argued that the only universal method characterizing scientific progress was anything goes.

Popper seems to have anticipated Kuhn's observations. In his collection Conjectures and Refutations: The Growth of Scientific Knowledge (Harper & Row, 1963), Popper writes, "[S]cience must begin with myths, and with the criticism of myths; neither with the collection of observations, nor with the invention of experiments, but with the critical discussion of myths, and of magical techniques and practices. The scientific tradition is distinguished from the pre-scientific tradition in having two layers. Like the latter, it passes on its theories; but it also passes on a critical attitude towards them. The theories are passed on, not as dogmas, but rather with the challenge to discuss them and improve upon them."

Another objection is that it is not always possible to demonstrate falsehood definitively, especially if one is using statistical criteria to evaluate a null hypothesis. ^{[citation needed]} More generally, it is not always clear that if evidence contradicts a hypothesis that this is a sign of flaws in the hypothesis rather than of flaws in the evidence. However, this is a misunderstanding of what Popper's philosophy of science sets out to do. Rather than proffering a set of instructions that merely need to be followed diligently to achieve science, Popper makes clear in The Logic of Scientific Discovery his belief that the resolution of conflicts between hypotheses and observations can only be a matter of the collective judgement of scientists, in each individual case. ^[6]

reposted from: Wikipedia
my highlights / emphasis / comments

Karl Popper - The Logic of Scientific Discovery (1934)

Karl Popper's 1934 Bombshell

In 1934 Popper published what many regard as his Magnum Opus The Logic of Scientific Discovery. In one majestic and systematic attack, psychologism, naturalism, inductionism, and logical positivism are swept away and replaced by a set of methodological rules called Falsificationism.

Falsificationism is the idea that science advances by unjustified, exaggerated guesses followed by unstinting criticism. Only hypotheses capable of clashing with observation reports are allowed to count as scientific. "Gold is soluble in hydrochloric acid" is scientific (though false); "Some homeopathic medicine does work" is, taken on its own, unscientific (though possibly true). The first is scientific because we can eliminate it if it is false; the second is unscientific because even if it were false we could not get rid of it by confronting it with an observation report that contradicted it. Unfalsifiable theories are like the computer programs with no uninstall option that just clog up the computer's precious storage space. Falsifiable theories, on the other hand, enhance our control over error while expanding the richness of what we can say about the world.

Any "positive support" for theories is both unobtainable and superfluous; all we can and need do is create theories and eliminate error - and even this is hypothetical, though often successful. Many superficial commentaries are keen to point out that other people stressed the importance of seeking refutations before Popper. They overlook the fact that Popper was the first to argue that this is sufficient.

This idea of conjecture and refutation is elaborated with an orchestration suggestive of someone who loves great music. (Popper loved Mozart and Bach, and took great pleasure in composing his own music.) The common idea that Popper neglected to consider whether Falsificationism itself is falsifiable is already scotched here. You can falsify a description, but not a rule of method as such (though obviously a rule can be criticized in other ways). The notion that science offers proof is now only advanced by popular treatments of science on TV and in (many) newspapers - most journalists (with a few important exceptions) are sadly completely devoid of theoretical knowledge: a side-effect of overspecializing on the immediate moment. But then, anyone can improve!

Most people who think they have a ready rebuff to Popper's position have never read his work. If they only read the original works, in most cases they would see that their supposed "Point that Popper neglected" had already been considered and exploded. A good example of this is Lewis Wolpert's remarks on Popper's works in his otherwise excellent book The Unnatural Nature of Science. He seems to think that Popper's falsifiability criterion ignores hypotheses about probabilities - overlooking the blatant fact that The Logic of Scientific Discovery devotes more than a third of its pages to the two fundamental problems of probability in an effort to find a solution that will also allow hypotheses about the probability of events to be capable of clashing with the evidence! Popper was in fact fascinated by probability and even produced his own axiomatisation of the probability calculus.

For the best current re-statement, defence and - more importantly - application of Falsificationism see David Miller's Critical Rationalism: A Re-Statement and Defence (click here for Amazon.co.uk). Miller was a very close friend and colleague of Popper's. He pulls no punches and is (despite his modesty) Popper's best knight. If you want razor-sharp logical accuracy, a full arsenal of arguments, and comprehensive demolition (with unrestrained collateral damage) of the opposition, Miller's book is the answer.

Karl Popper - Greatest Philosopher - advocated by Andrew Marr

	GREATEST PHILOSOPHER


Karl Popper (1902-94) advocated by Andrew Marr Listen to Andrew Marr say why you should vote for Karl Popper 'Philosophers should consider the fact that the greatest happiness principle can easily be made an excuse for a benevolent dictatorship.' A British Philosopher of Austrian birth, Karl Popper is famous as a philosopher of science. He questioned traditional ideas that firm scientific laws could be established through observation and experiment and argued that absolute truth was alien to the scientific method. For example, 'all cats are black' is a theory that can never be verified because we can never observe all cats. However, it could be falsified by the observation of one white cat. Thus scientific theories should not be said to be true: at best they can hope not to be proven false. Indeed this is the essence of a proper scientific theory - if it is not open to being proven false then it is merely pseudo science or even myth. This is known as Popper's falsification principle. Popper also argued for the significance of the individual against Marxist and Hegelian ideas of the inevitable process of history. After all, the process of history is influenced by human knowledge and the future of knowledge is unpredictable (else we'd already know it). In the political arena he was perhaps best known for his contention, set forth in The Open Society and Its Enemies (1945), that communism and fascism were philosophically linked, and his works provided some of the theoretical underpinnings for Thatcherism. Read about Karl Popper on Wikipedia Read about Karl Popper on the Stanford Encyclopedia of Philosophy Please note: the BBC accepts no responsibility for the content of external websites. Listen to Andrew Marr say why you should vote for Karl Popper Andrew Marr Andrew Marr is the BBC Political Editor and presenter of Radio 4's Start The Week. He was born on 31 July 1959, in Glasgow, Scotland. He attended Dundee High School, Craigflower School in Fife, and Loretto School, Musselburgh. He then gained a BA in English from Trinity Hall, Cambridge. He joined The Scotsman in 1981 and became editor of The Independent in 1996, before being appointed as BBC political editor in May 2000. Andrew lists his hobbies as reading, painting, cooking and remembering his children's names.

reposted from: BBC Radio 4
my highlights / emphasis / comments

In Our Time's - Greatest Philosophers

VOTE RESULT





In Our Time's Greatest Philosopher Result The final top ten positions are listed below. You can still read the profiles and enjoy some stimulating advocating by our experts or go to the full shortlist for all the special pleadings in the vote. Listen to Melvyn Bragg announce the winner on Radio 4's Today.