- Affirming the Consequent is a logical fallacy that takes a known true statement [if P then Q] and invalidly concludes its converse [if Q then P]:
- If Bill Gates owns Fort Knox, then Bill Gates is rich. Bill Gates is rich. Therefore, Bill Gates owns Fort Knox. False!
- If an animal is a dog, then it has four legs. My cat has four legs. Therefore, my cat is a dog. False!
- If it’s raining, then the streets are wet. The streets are wet. Therefore it’s raining. False! It could be raining or it could be something else. The “therefore” claim is false.
- How does ‘Affirming the consequent’ apply to evolution? We have not observed “evolution”. No one has, and no one will, despite the effort (see LTEE). What was observed is Resemblance, the Birth Mechanism, Variability and Adaptability. Neither of these (even combined) can logically be extrapolated to “evolution”, namely the hypothesized transmutation of one type of organism into another. Proofs of “evolution” always take the form: If “evolution” is true, then XYZ is true. XYZ is true. Therefore “evolution” is true. This is a classical Affirming the Consequent logical fallacy.
- Let’s see some concrete examples of “proof of evolution” fallacies:
- If “evolution” is true, some fossils are ancestors of and therefore resemble existing organisms. Fossils resemble one another and existing organisms. Therefore “evolution” is true. This argument fails because there will always be some resemblance between two or more entities (even chairs and cats have four legs in general). Also, a fossil can always be from an unrelated branch of the “tree of life” which circularly presupposes “evolution” anyway.
- If “evolution” is true, organisms are genetically similar. Organisms are genetically similar. Therefore “evolution” is true. This argument is false because other hypotheses such as common design account for genetic similarities just as well.
- If “evolution” is true, one might expect common embryology. Similar organisms have similar embryology. Therefore “evolution” is true. This fails because embryology is expected to match genetics and morphology, hence the previous counterargument applies.
- If “evolution” is true, one might expect vestigial organs. What looks like vestigial organs can be observed. Therefore “evolution” is true. This fails because what if those organs are useful rather that “vestigial”? And why would “evolution” not do away with “vestigial” organs as soon as they become useless? In sum, why can’t these organs have another reason or origin than “evolution”?
- If “evolution” is true, one expects adaptability such as antibiotic resistance. Antibiotic resistance is observed. Therefore “evolution” is true. This fails because adaptabilities such as antibiotic resistance are compatible with other hypotheses, not just “evolution”. In addition, antibiotic resistance is ubiquitous, limited, reversible, and never observed to result in organism transmutation aka “evolution”.
- How can “proofs of evolution” avoid the ‘Affirming the Consequent’ logical fallacy? Direct confirmation of “evolution” is unlikely as shown by the LTEE study. Alternatively, an observation that is true for “evolution” and only for “evolution” might also work. In other words, what’s missing from all the examples above is a true statement of the kind: “only if evolution is true, then XYZ”. Of course, excluding all alternatives to “evolution” is an impossible task therefore, given that Intelligent Design is the main rival, proponents of “evolution” need only add a true statement of the kind: “if Intelligent Design is true, then XYZ is not true” to turn their invalid arguments into valid ones. But even this lower bar cannot be met by “evolution” proponents, thus making all “proofs of evolution” invalid.
- Isn’t then all science ‘Affirming the Consequent’? For example, “if Newtonian physics is true, a ball thrown at angle Theta and speed V will land D meters away. The experiment is carried out, and we find that the ball landed distance D away. Therefor physics is true.” No! This is not a fallacy because it meets the “if and only if” requirement and is limited to “everything else equal” cases. Rockets do not disprove this claim because everything else is not equal between them and thrown inactive projectiles. In addition, no one claims a single experiment confirms all Newtonian Mechanics the way “proofs of evolution” are presented. In this case, multiple combinations of Angles and Speed result in the same Distance without violating Newtonian Mechanics because this experiment proves only portions of the theory.
Links:
https://en.wikipedia.org/wiki/Affirming_the_consequent
https://www.amazon.com/Biblical-Wisdom-Literature-Joseph-Koterski/dp/1598035258
Well said! Best post I’ve seen in a while.
Here’s what it takes to observe evolution: A change in the frequency of an allele in a population. Done, case closed, game over.
What the hell is “Resemblance”? Are you talking about heritability, the propensity for offspring to look like, aka resemble their parents?
And “the Birth Mechanism”(capitalized?), what’s that? Reproduction?
Is “Variability” supposed to be variation, as in genetic and physiological differences between individuals?
Adaptability is just another way of saying change in the frequency of alleles due to natural selection, so when creationist ultradenialists insist on using the word “adaptability” instead of evolution by natural selection we know they’ve already lost the argument because they’re so afraid of conceding anything remotely related to evolution, they feel forced to invent a new word to describe the same phenomenon.
Dude, what’s the deal with your own personal undefined vocabulary here? Are you so desperately afraid of the concept of evolution you want to establish a new set of words to describe all the same phenomena just so you can superficially declare it’s not evolution because lol omg none of the words are the same?
The gig is up buddy.
That’s not the definition of evolution, it’s some dumb shit you made up. The closest thing in the actual biological science of evolutionary biology would probably be macroevolution, but even then not really, since speciation and extinction are macroevolutionary phenomena and don’t necessarily constitute “transmutation” of a “type” of organism, whatever the fuck that even is.
That whole op is…
Um, not so fast. Theistic evolution & evolutionary creation both differ from atheistic evolution and ‘Darwinism.’ BioLogos & Peaceful Science, as well as most people in the ASA, openly reject so-called ‘Intelligent Design’ theory. Were you aware of this?
At least you capitalized ‘Intelligent Design’ properly, which IDists at the DI don’t do. If they did, the IDM would quickly collapse, because from a sociological perspective, they require the illusion that ‘it’s Designed’ is a ‘strictly scientific’ claim (just like their atheist counterparts). It doesn’t matter if IDists cannot and will not openly name (only behind closed doors) the Intelligence directly, or posit when, where and how the instantiation of this ‘Intelligence’ can be measured using strictly science & explicitly not involving theology or worldview.
It’s a major question when this goes beyond being just a ‘strictly scientific’ topic, at which point scientists are again amateurs, not experts. Yet biologists seem to have a penchant for talking beyond their expertise as if people should listen to them, just because they’re a ‘scientist’. The biological hubris.
Really, there’s just one definition? LOL!
I applaud that you are now conceding that evolutionary theory is a possible explanation for a great number of observations. That’s a major improvement from your previous OPs.
I do wonder what parts of the OP were cited from the “Biblical Wisdom Literature”.
By the way, even your attempt at exposition on the fallacy of affirming the consequent is incompetent at best. You cannot claim that a conclusion is false just because it was arrived at by an invalid inference, on that alone all you can say is that the conclusion doesn’t follow from the premise. The conclusion might be false, but the mere fact that a person stating it arrived at it fallaciously does not allow you to declare that.
Bill Gates might actually be the owner of Fort Knox, it’s just that Bill Gates being rich is not what makes him the owner of Fort Knox.
If I am the offspring of my biological mother, then I will have at least one of her traits. I have at least one of her traits, therefore I am the offspring of my biological mother. This is an affirming the consequent fallacy, but both the premise (I have at least one of her traits) and the conclusion (I am the offspring of my biological mother) are both true. But the inference is invalid, because sharing a trait with my biological mother is not the only way I could come to have that trait. My dad could have had it too.
With respect to this claim:
You give zero concrete examples of anyone committing these fallacies, rather you just make up a couple of examples that you purport is how evolution is concluded. I have never seen anyone argue that evolution is true using arguments of the form you have provided. So please give actual examples from the biology literature of anyone engaging in those fallacies.
This demostrates a fundamental misapprehension about how science works. Nothing is deductively proven in science. No scientific theory has ever been “proven”, as it is always possible to give an alternative hypothesis that postulates that the observed was caused by a different phenomenon. There is no proof of thermodynamics, for example, or proof of general relativity, or proof of Lambert Beer’s law.
I’m convinced.
What god should I start to worship? How did you pick your one nonlin?
It appears that Nonlin is confusing the testing of predictions with the fallacy of affirming the consequent.
The OP rests on three really serious confusions: one between distinct types of reasoning, one between kinds of necessity, and one between kinds of scientific explanation.
1. Affirming the consequent is a fallacy of deductive logic. The argumentative structure in most modern science, including evolutionary theory, is not deductive but what Peirce called abductive logic or what epistemologists today call ‘inference to the best explanation’.
2. It is true that in physics we can get statements that look like deductive statements, but this is misleading. It is because fundamental physics is often articulated in terms of laws. Laws of physics (if there are any) are not the same kind of necessity that deductive statements have. This can be seen easily once we notice that the necessity of logic holds in any possible world, and the necessity of physics holds only in the actual world.
3. It is sometimes thought that scientific explanations consist in searching for universal laws or law-like generalizations. This is a contentious claim amongst philosophers of science today. Fodor, rather infamously, insisted that evolutionary theory was not genuinely scientific precisely because it did not involve laws. Other philosophers of science take the view that physics is special precisely because it involves laws. It is hard to see what the laws of ecology are, yet no one would deny that ecology is a science regardless of whether evolutionary theory is true or false. Likewise, it’s hard to see what the laws of neurophysiology are.
So the attempt to condemn evolutionary theory by squeezing it into the Procrustean bed of deductive logic, while at the same making an exception for Newtonian mechanics, just doesn’t work.
Yes, that’s a shorter and more concise way of putting my point.
Nonlin,
Some kind of “evolution”, or change, within kinds had to have happened after Noah’s flood…
We can observe it today within wolf kind, where the interbreeding between wolves, coyotes, dogs etc. produced a great variety of coy-wolves, coydogs…
This kind of evolution doesn’t fit the Darwinian dogma of slow, small changes overtime. The major changes with in wolf kind happen within one or few generations…
Most, but not all, “evolutionary” changes from wolf to dog are due to damage to genes, such us growth hormone mutations, cartilage, bone, joints abnormalities due to mutations…
https://advances.sciencemag.org/content/2/7/e1501714.full
The evolutionary claim never proven or observed is the origin of the new body plans…
So, bacteria without a flagellum never evolved a flagellum and wolfs or dogs never developed new organs or bones…
One of the recent proofs of the lack of any real evolution is the polar bear evolution from the brown bear…
Brown bears can develop a pigment mutations and lose brwon fur color within one or few generations.
The so called cholesterol evolution is a hoax…
Behe and DI fell for it…unfortunately 🙁
Polar Bear Evolution Was Fast and Furious (lol)
https://www.sciencemag.org/news/2014/05/polar-bear-evolution-was-fast-and-furious
Nonlin isn’t arguing against evolution specifically. Nonlin is arguing against the validity of the scientific method itself. Go figure.
Nonlin,
The evidence for evolution is not similarities between species. The evidence for evolution is a correlation between the phylogenetic signals found in two data sets: morphology and genetics. It is the PATTERN of similarities AND differences that evidences evolution. You need to address this evidence.
More than that. It is also the correlation between the phylogenetic signals between different parts of the morphology and between different parts of the genetics.
When you start out with a blatant falsehood, why would I be compelled to read the rest of this?
From the article:
“In other words, what’s missing from all the examples above is a true statement of the kind: “only if evolution is true, then XYZ”. Of course, excluding all alternatives to “evolution” is an impossible task therefore, given that Intelligent Design is the main rival, proponents of “evolution” need only add a true statement of the kind: “if Intelligent Design is true, then XYZ is not true” to turn their invalid arguments into valid ones. But even this lower bar cannot be met by “evolution” proponents, thus making all “proofs of evolution” invalid.”
The problem for Nonlin is that this is true for all scientific theories, including Newton’s theories of gravity. In the cast of Newton, we can’t rule out invisible fairies guiding an object through space in a parabola consistent with Newton’s equations. Therefore, the theory of gravity is as invalid as evolution according to Nonlin’s argument, and for the same reasons. In trying to destroy the theory of evolution, Nonlin has to tear down all of science.
T_aquaticus:
Just a slight quibble, but an interesting one, I think: the path in that case wouldn’t really be a parabola. Only if gravity remained unchanged with distance would it be a parabola.
We all computed parabolas in our introductory physics courses, but that was because we were told to assume that the acceleration due to gravity was a constant 9.8 m/s^2. That’s an acceptable approximation near the earth’s surface, but for objects in outer space, such as planetary probes doing “slingshot” maneuvers, the assumption of constant acceleration will introduce a significant error.
T_aquaticus:
Right. It’s an interesting phenomenon: Critics like Nonlin are so fixated on tearing down evolution that they fail to notice the collateral damage they cause to their own positions.
Nonlin:
“Vestigial” doesn’t imply “useless”. See
http://www.talkorigins.org/indexcc/CB/CB360.html
You might want to spend some time at TalkOrigins.
I thought the nit pickers would have focused on the much more obvious effects of air resistance causing deviation from the predicted trajectory. There is also the fact that Newton’s equations were replaced by Einstein’s, so you could have nit picked the deviations caused by relativity.
So many nits, so little time. 😉
Right, though Nonlin could have avoided this objection if they had been more clear about the difference between logical necessity and physical necessity and also between descriptions and explanations. It must be the case that the magnitude of force is equal to the magnitude of mass times the magnitude of acceleration, as a descriptive claim that holds everywhere in the universe (to the extent that Newtonian mechanics is correct anyway). That’s a way of cashing out the “only if”.
T_aquaticus:
I interpreted “through space” as “through outer space”, where air resistance wouldn’t be a factor.
Except you specified that we were talking about Newtonian gravity.
Like I said, it’s a quibble, but I think it’s an interesting one. The path is actually hyperbolic if the speed is high enough and elliptical otherwise.
Not when you tan or fight an infection.
There’s a different OP that completely demolished “natural selection”. Feel free to discuss here: http://theskepticalzone.com/wp/natural-selection-evolution-magic/
Btw, it’s clearly a hit when you’re so pissed 🙂
Nonlin:
“Completely demolished”? Your hubris is amusing.
Not significantly. And because of that, they employ the same fallacy as Darwinistas.
The one that matters here. Remember “origin of species”
and other such nonsense?
Not really. But if it were, its “proofs” would still fail.
Sorry to disappoint, not. On the other hand, I worked so hard on you, and now you’re disappointing me by returning to your old mistakes 🙂
Excellent question! That’s where this logical fallacy clicked with “evolution” for me. Of course, the author was talking about something else.
You’re trying too hard… or not hard enough.
“Therefore, Bill Gates owns Fort Knox” fails because of “therefore”.
Nothing except evolution: http://evolutionfaq.com/articles/five-proofs-evolution , right?
Best of WHAT? Sooo funny 🙂
I’ve already shown where “evolution” differs:
“In addition, no one claims a single experiment confirms all Newtonian Mechanics the way “proofs of evolution” are presented. ”
Not only. Then you agree? Some people here reject Fodor.
I already mentioned Variability. Check out how all KNOWN variability reverts:
Darwin’s finches revert. Peppered moth reverted. Antibiotic resistance reverts. Epigenetics revert. The LTEE eColi would revert if released (go check out this prediction!). Etc, etc.
Did you see this:
“What was observed is Resemblance, the Birth Mechanism, Variability and Adaptability. Neither of these (even combined) can logically be extrapolated to “evolution”, namely the hypothesized transmutation of one type of organism into another. ”
“Attacking the scientific method”? But not finding any fault with Newton? Hmm. You figure it out.
This was also discussed ad nauseam. But feel free to continue: http://theskepticalzone.com/wp/nested-hierarchies-tree-of-life/
Good question. Not so! Newton DOESN’T CARE what drives gravity. He just states the obvious observation-based law. And of course, we still don’t know how gravity works.
A chihuahua will not revert back to a wolf…
At doing what, and which one is it?
That merely shows it is an inference, it doesn’t show the conclusion to be false. I hope you understand the difference between showing an inference to be invalid, and showing the stated conclusion of the inference to actually be false.
No, not right. No scientific theory, including evolution is actually proven in the way you are insisting it must be. But congratulations on having found a website where someone else mistakenly employs the word proof like you do, that just makes there be two of you who are wrong when you use the word proof about scientific theories.
There you go with your strangely altered personal vocabulary again. It’s called variation, not variability.
They just adapt to their food source. If they go back to a previous food source, they re-adapt to it. That’s still evolution. The fact that they can adapt to an environment they left isn’t in any way problem for evolution.
The dark phenotype still exists in the moth population, it rose in frequency during the industrial revolution when there was a lot of pollution, then later the frequency dropped again when the pollution was curbed.
That’s textbook evolution by natural selection by the way. The original dark phenotype arose by spontaneous genetic mutation(by transposition IIRC), then became favored by environmental change so rose in frequency due to increased relative reproductive success of carriers compared to the bright phenotype, then when pollution stopped the selective pressures again favored the bright phenotype so the dark phenotype dropped in frequency.
If the selective pressure is not maintained, the adaptation is eventually lost to accumulating mutations. That’s still evolution.
What do you mean? Are you talking about the fact that environmentally sensitive gene expression changes in response to change in the environment?
This claim of yours is amazing for how many wrong and unclear things seem to be implied by so short a sentence. First of all it’s E. coli, not eColi.
Second, it’s not clear what you even mean by reversal here. Reversal to what? The full ancestral state, genetically and phenotypically? How would that even happen? Don’t bother even contemplating an answer here, we know you haven’t the slightest of clues.
Third, released? It lives in your intestines, it’s not like it’s being kept in a cage or barn. Fourth, it’s your own goddamn job to demonstrate the truth of your claims, we are not required to prove your predictions wrong and labor to produce your agreement. You are required to substantiate them in the first place and until such a time as you have done so, they should simply not be believed. You’ll note scientific publications don’t normally take the form of “We hereby declare X is the case, now prove it wrong to our satisfaction or we will continue to believe X”.
How do you know?
When?
Well, I am not so sure about that, but will a dwarf revert back to Yao Ming? If not, then are dwarfs a new species/example of evolutionary transitions?
Do you realize that a chihuahua is a result of a selective breeding where genetic defects where selected for, such as dwarfism? For a Chihuahua to return to a wolf, the interbreeding with wolves would have to be possible first….
While wolves and chihuahuas look somewhat different, they still share the same body plans… they’re a part of the same kind, whether the changes within the kind are reversible or not…
The chihuahuas have the normal growth-hormone and fur production disruption due to mutations…
Of course I realize that, that’s why I wrote it. Its my point. Its the same reason why plants can look so varied and yet still be the same plant family, forever, and ever…
Lots of variation, no change, that seems to be the only story of evolution we can ever see.
Then better show that the proofs fail. In arguing for the fallacy of the converse, you are conceding that evolutionary mechanisms fulfill their role as a possible condition in a large number of independent observations. From your link:
emphasis mine
The mutation responsible for the carbonaria morph has been identified as a transposable element insertion.
The event has been estimated to have occurred in the beginning of the 19th century. Paper abstract here.
H/T Dave Carlson
Did you really mean to write it that way?
Sure, unless you think every human is a new species.
Corneel,
I doubt it.
“MODERN SCIENTISTS ARE WRONG FAR MORE THAN YOU THINK
Statisticians have shown that many scientific findings are wrong, and without an increase in statistical know-how for scientists it’ll continue happening.”
https://psmag.com/education/scientists-are-wrong-a-lot
So what you really meant was, “lots of variation, no change of kind”.
We can run experiments where the emergence of antibiotic resistance is due a random mutation. This is quite different from tanning or immunology, and yet you lump them together. You need to read up on how biology works before criticizing it.
We do know how gravity works. It is due to the warping of spacetime. You need to catch up on your physics education.
What do you have to say about rejecting the scientific method as a valid way of determining how the universe works?
Did you see what I wrote? It is the PATTERN of similarities AND differences that evidence evolution, not simply resemblances. That pattern is a nested hierarchy.
You are attacking the scientific method itself in your campaign to get rid of evolution. What do you have to say for yourself?
Aren’t you “affirming the consequent” according to your own argument? If evolution is false, then variability will revert. Variability reverts, therefore evolution is false. Do you see the problem?
Lots of variation within the specific kind (some reversible and some probably not) but no new kinds are produced…
The mechanism of variation, such as mutations seem to be controlled by quantum processes. Whenever a mutation happens within the genome, that leads to a cascade of processes, such as other mutations etc via quantum entanglement for example… Behe referees to these processes in Darwin Devolves without being aware that quantum entanglement is a prefect candidate to explain the cascade of the events…
Lots of variation within specified kind but no new kinds arising due to the variations within the kind…