Justus For All

This was a neat little page that I found that stimulated at least the following thoughts:

1. A Scientific theory is a model of a natural process.

2. The basic components of the model are multiple hypotheses that have not been disproven via statistical analyses of experimental data.

3. A Scientific theory is a predictive model; to qualify as a theory, it is insufficient for the model to merely explain prior observations. It must be prospectively valid and testable.

I would qualify #2 by specifying falsifiable hypotheses. Your typical member of the “scientific community” assumes a hypothesis will be falsifiable, but not everyone makes that assumption.

That, of course, is my problem with ID. It presents no falsifiable hypotheses.

Yeah, yeah. I broke the “No ID discussion” rule. That’s what I get for not reading ahead. Sue me.

well, define for me a “falsifiable” hypothesis. I rather think I get around that by making it a requirement that an hypothesis be testable. The way you use the term “falsifiable”, I get the idea that one of your requirements is that there must be some fraudulent way to not-disprove hypotheses. I’m not sure you need that kind of requirement.

Actually, #3 states that the theory must be testable.

When I say that a hypothesis must be “falsifiable”, I’m saying it must present prerequisite and implication, such that, 1) The prerequisite is manipulable, 2) the implication is measurable, 3) prerequisite implies implication.

For example, suppose the hypothesis “All cows are brown.” As it is possible to observe a variety of cows, request remote cow observations, and new cows are continually coming into existance, I would call the prerequisite “manipulable”. If I gave it more time, I’d probably use a different adjective.

As we are able to determine the color of an observed cow, request independantly verifiable photographs, or even samples of cow hair, I would consider the implication measurable.

To falsify “All cows are brown” then, we need only produce a black cow, a photo of a black cow, or samples of black hair, otherwise provable to have come from a cow.

Conversely, “Frogs dance when Aphrodite tells them to” is not falsifiable, as we cannot produce Aphrodite to give the order, and a lack of dancing frogs may only prove that Aphrodite hasn’t spoken to them lately.

I would say that my definition of falsifiable is roughly synonymous with what you would call testable, though it should proably be more clearly called out. I guess the big question is, does each hypothesis need to be testable, or only the theory as a whole?

Falsifiability, was developed by Karl Popper to address exactly this difficulty. This Wikipedia page also provides a good overview, along with what I think is a powerful criticism of this idea:

As Sokal writes, “When a theory successfully withstands an attempt at falsification, a scientist will, quite naturally, consider the theory to be partially confirmed and will accord it a greater likelihood or a higher subjective probability. … But Popper will have none of this: throughout his life he was a stubborn opponent of any idea of ‘confirmation’ of a theory, or even of its ‘probability’. … [but] the history of science teaches us that scientific theories come to be accepted above all because of their successes.”

That said, falsifiability may indeed be a useful comcept. I wonder though if it is equally applied to accepted theories as it is to theories that are unaccepted, do we assume that because a theory is accepted it must be falsifiable?

Beyond that of course is the question of how to deal with synthesis of multiple theories into a larger theoretical structure, evolution would be a good example of this. Each individual theory of a theoretical structure may be falsifiable, but it the joining together of them still falsifiable? That may be more difficult to determine.

Some areas of science are also less ammenable to testing by default, once again evolution is a great example. We only have one ‘test’ and very incomplete data on that test. As we aquire new data, typically we see it either as a confirmation of the theory, or as an expansion of it. This last step, would be something Popper called a conventionalist stratagem, and some that he deplored, but is of course very common in science.

There was an interesting little comment I heard, whilst lying in the sun with a very cold beer to hand, along these lines…

EVERY organism, whether produced sexually or asexually (use scientific definitions there, please!) can and probably does have genetic mutations not produced from the parental genetic material.

The vast majority of those mutations have little or no impact.

A small number of those mutations might impact the survivability of the organism in some way – red hair, fair skin, and susceptibility to skin cancer for example.

An even smaller proportion of those might be fatal to the organisation – physical deformities, including enzyme and glandular function. Consider here that diabetes is a purely human “disease” caused by the inability of the pancreas to produce insulin. The process of sugar conversion however is common to all mammals. The increasing rates of human diabetes is in large part the result of having a “cure” for the mutation that causes the disease… Sorry, I digress but the illustration is pertinent…

Back to the general case.

Evolution is a very gradual process. The mutations involved in creating a new species are comparatively huge. The steps involved are extremely small. Every single one of those steps could result in the expiration of all the previous mutations.

The ID vs evolution debate is very largely predicated on large and instant steps – a proto-lion is changed to a lion or a tiger or a cougar “overnight”… instead of developing from common ancestors over many thousand generations… and without reflecting the differing environments in which they developed…

Undone by my tendency to paraphrase! I quote, now, directly from Popper’s The Myth of the Framework: In defence of science and rationality, the chapter Science: Problems, Aims, Responsibilities:

The criterion of refutability, or falsifiability, or testability, is only the first step in the solution of Bacon’s problem. As we have seen, this step is taken by asking a scientist who claims that his theory is supported by experiment or observation, “Is your theory refutable? And what experiment or observation would you accept as refutation?”

The solution amounts to this. Agreement between theory and observation should count for nothing unless the theory is testable, and unless the agreement is found as the result of serious attempts to test it. But testing a theory means trying to find its weak spots. It means trying to refute it. And theory is testable only if it is (in principle) refutable (Karl used italics instead of bold, there).

I have been trying to articulate this in my ape-like way for several posts now. Apes read Nietszche, they just don’t understand Nietszche!

I prefer the term “refutability” to “falsifiability”. Popper uses the terms interchangeably; maybe this is an artifact of translation from German but I believe Refutability is the more precise term for his concept.

Above post also undone by 1.)my pathetic HTML skillz, and 2.) Dave’s failure to provide me a means to edit my posts. The Karl Popper quote runs from The criterion of falsifiability, or refutability or …up until … theory is testable only if it is (in principle) refutable.

I think we need to distinguish between “Not being falsified proves a theory” and “Being falsified disproves a theory.” A theory isn’t particularly valuable if it can’t be disproven.

It is certainly the case that every theory should be subject to being disproven, regardless of longevity. While I’m sure any scientist you’d speak to would say that’s the case, you’ll also find that the longer a theory has remained without being disproven, the more useful it will be even once it is disproven.

Take the example of Newton’s theories of motion. They were subsequently disproven my the theory of relativity, which is in the process of slowly being disproven by quantum theory. Regardless, they all remain useful, as they describe, in simpler terms than the newer theories, everyday physical behavior.

I’m not sure why a theory would suddenly not need to be testable if it were part of a group of related theories. The more pertinent question is whether disproving one theory of that group automatically disproves the overall construct. It certainly doesn’t necessarily disprove the other theories.

That same question then can apply to the hypotheses that make up a theory. What does disproving one do to the overall theory? I don’t think there’s any doubt that it means a re-thinking is in order.

Technically, theories aren’t proven, Dave Miller, only repeatedly not-disproven.

Newtonian physics is not invalidated by relativity; just modified for extreme conditions of scale not imagined (or perhaps imaginable?) in Newton’s time. Neither has Max Planck’s quantum theory (which preceded Einstein’s two landmark papers on relativity) disproven relativity.

“Technically, theories aren’t proven, Dave Miller, only repeatedly not-disproven.”

Sorry if I wasn’t clear. Dave seemed to be asking “At what point is a theory proven by not being disproved?” and my reply was in part an attempt to say exactly what you did.

As far as Newtonian physics v. Planckian v. Einsteinian, that’s true, they weren’t disproven as a whole, simply individual hypotheses of the theories were shown to be more limited than originally thought, by being disproven as a general condition. That comes back to my final thought before, at what point do you call a theory disproven?

I haven’t got into proven or disproven yet, more important to me at the moment is scientific or unscientific.

If we were to go with a statement about natural law that can conceivably be disproven, then how well does evolution fit within our definition? I assume we agree that evolution is a scientific theory, made up of several component theories…can we identify the component theories and are they falsifiable/refutable?

Although I think we should treat any dominant scientific theory with skepticism, I am afraid I do not have the patience to analyze why darwinian evolution is science.

I guess if Erich von Daniken comes down from the sky with video documentation of ancient astronauts artificialy inseminating australopithecines, it might impress me.

I think that’s where I stand as well. It might not be complete (but neither was Newtonian Physics), It might not explain everything (Look at Quantum Mechanics and General Relativity) – but Evolution is about the best that we have.

We have real evidence that it happened, and is happening to us right now. We have no evidence for ‘other hypotheses’. Those others are providing no evidence.

If I were to proclaim that Aliens built the Pyramids, and they were actually the landing pads for great star ships… I would be in the same boat as those ‘Others’. No evidence, only speculation.

Speculation is a good place to start. However, speculation does not science make. Science is when that speculation is put to the test, and shows that it’s up to muster. I would posit that ID is not up to muster. We should not teach Infinite Causes as a scientific theory that is on par with evolution in High School any more then ID.

I think you guys are misunderstanding me. The purpose of this excercise is NOT to cast doubt on evolution. As I stated in the original post, any definition of a scientific theory that EXCLUDED evolution is not a definition of scientific theory that I can accept. I am wondering if our Popperian theory will pass the test, not if evolution will.

I contend that if evolution is not falsifiable that falisfiability cannot be a valid test for what is and is not science.

My reluctance to proceed stems from the fact that this task would recapitulate 4 years of my undergraduate education (pre-med), then much of the first two years of medical school, followed by intermittent periods of my post-graduate medical education and post-post-graduate medical education.

Dave Justus, why don’t you just go off and get a master’s in molecular biology? That would be easier on me.

Okay, then. Let’s get a little help from Papa Karl. Quotes from same chapter cited above:

“10. The fundamental role played in science by theories or hypotheses or conjectures makes it important to distinguish between testable (or falsifiable) and non-testable (or non-falsifiable) theories.

11. Only a theory which asserts or implies that certain conceivable events will not, in fact, happen is testable. The test consists in trying to bring about, with all the means we can muster, precisely these events which the theory tells us cannot occur.

12. Thus, every testable theory may be said to forbid the occurrence of certain events. A theory speaks about empircal reality only in so far as it sets limits to it.

13. Every testable theory can thus be put into the form ‘such and such cannot happen’. For example, the second law of thermodynamics can be formulated as saying a perpetual motion machine of the second kind cannot exist.

14. No theory can tell us anything about the empirical world unless it is in principle capable of clashing with the empirical world. And this means, precisely, that it must be refutable.

15. Testability has degrees: a theory which asserts more, and thus takes greater risks, is better testable than a theory which asserts very little.

16. Similarly, tests can be graded as being more or less severe. Qualitative tests, for example, are in general less severe than quantitative tests. And tests of more precise quantitative predictions are more severe than tests of less precise predictions.”

So here is my qualitative test. One of the historic difficulties with submitting darwinian evolution (DE)to an experiment was its slow time course. Until Mendel started messing with fruit flies, genetics and mutations occurred at such slow rates that selection pressures could not be evaluated.

With the development of the polymerase chain reaction, DNA recombinant technology, etc., it became possible to track mutations at the gene level within a time frame that allowed meaningful observation.

So with contemporary molecular biology methods, now we can formulate a refutable assertion which comports with Popper’s thesis #13 as cited above. The assertion can be “In the absence of selection pressures, mutations which lead to adaptive phenotypic traits do not arise”.

Then, we take two dishes full of naive e. coli and start pounding one with penicillin (a selection pressure). We don’t do anything to the other dish. Voila, the little guys in the penicillin dish come up with a beta-lactamase gene after a few generations and laugh at your penicillin. No beta-lactamase gene emerges in the control dish.

Certainly one component of the theory of evolution is Mendelian Genetics and Microevolution as you described above. I agree that both of those items would be falsifiable.

That doesn’t seem to be the complete theory of evolution. We still have to account for Macroevolution, for example. I don’t expect a dissertation on each of those components, nor do I require that a Popperian expirament be practicle for each of these major components, as long as a Popperian expirament is conceivable for them.

BTW: Mendel did not work with fruit flies, he worked with pea plants primarily.

With regard to Mendel & fruit flies vs. pea plants: yes, of course, you are right and I stand corrected.

Ok… How about this:

A Scientific Theory is speculation (a hypotheis) that has had an amount of testing and peer review of said testing. It has parts which can be proven to be true or false with emperical evidence that can be readily reproduced.

Short, sweet and to the point. I think that covers all of the bases – if not, Please Feel Free to Correct!

Tsykoduk’s definition takes a slightly different direction than that Popperian one above. It seems to me to be a little weak in specificity, ‘and amount of testing’ and ‘parts which can be proven.’ To be useful I think we would have to narrow that down a somewhat. Certainly a hard number or percentage would not be appropriate but something that would narrow it down more than it is.

Is the bones of this definition worth trying to flesh out or would attempting that be going on the wrong track?

BTW, that was “pea plants”, not to be confused with MC Pee Pants

apologies in advance if the HTML is f*cked

crap! images not allowed. link: http://upload.wikimedia.org/wikipedia/en/c/cd/Peepants.jpg

I have a couple of very good books on evolution and scientific investigation that may provide more stable information for you to masticate in regard to your general querie. If you are interested let me know and I will bring them this weekend.

X

Any further thoughts on this? At this point I have to regard the attempt as a failure.

I would not say that it’s a failure. Several very good models were presented – all of which are very close to reality. Is it a failure just because you do not agree?

When dealing with concepts, it’s all about semantics. Words are symbols for ideas – and if we have different ideas what those symbols are, we are never going to be able to communicate. A Scientific Theory is defined as

In science, a body of descriptions of knowledge is usually only called a theory once it has a firm empirical basis, i.e., it

1. is consistent with pre-existing theory to the extent that the pre-existing theory was experimentally verified, though it will often show pre-existing theory to be wrong in an exact sense,
2. is supported by many strands of evidence rather than a single foundation, ensuring that it probably is a good approximation if not totally correct,
3. makes predictions that might someday be used to disprove the theory,
4. is tentative, correctable and dynamic, in allowing for changes to be made as new data is discovered, rather than asserting certainty, and
5. is the most parsimonious explanation, sparing in proposed entities or explanations, commonly referred to as passing Occam’s Razor.

–Wikipedia

When it comes down to it – that is what a Scientific Theory is – not because of some platonic ideal, but rather because of an agreement on it’s definition.

A person can decide that they want to use some other definition – however their ability to effectively communicate will be rather hampered. I could decide that fire was cold and up down, but when I call the snow murder and tell them that my ipod is freezing, will they laugh, or come and put the fire out on my house?

This is why we have dictionaries. We need to be able to all agree on what symbols refer to what concepts. We already have a concept tied to the symbol of Scientific Theory. There is no need to try and invent another one.

There was a bit of “reinvent the wheel” to it…

I considered the discussion a failure, not necessarily a waste of time or unuseful because we had not been able to state a definition of scientific theory that was specific enough and seemed to match up with ideas that were agreed upon.

I certainly was not trying to insist that this definition be an original work, or trying to come up with something that would be a definition that did not match up with people’s concept of scientific theory.

I think that the Wikipedia definition is considerably better than anything we have played with previously in this comment thread. That said, I am not necessarily willing to consider Wikipedia the source of all wisdom.

I note right off that the definition includes the words usually. I am not necessarily opposed to this, a certain flexability seems to be required but it does make me wonder when an exception would be appropriate.

Secondly, and related, are the 5 requirements above equally important or should they be considered to have different relative importance. If the latter, what should that order be?

Lastly, are we content with those 5 requirements. Is one of them extraneous and able to be removed or should a sixth be added?

I don’t in general think that it is a waste of time to examine one’s premises and ensure that everyone is talking about the same thing. I also think that being precise in definition and terminology is important in some discussions.

Maybe science is like pornography: I don’t know how to define it, but I know it when I see it!

I have had the exact same thought a few times during this discussion myself….