Several commentors and I have been having a discussion of teleology and purpose in biology.
Teleology is a metaphysical theory that change in nature is generally restricted to a limited array of outcomes. Striking a match causes a flame, but never an atomic explosion, or an ice cube.
Some philosophers have noted that teleology invokes the notion of "purpose" in nature. There often seems to be a striving, a goal-orientedness, to natural processes. Purpose seems particularly obvious in biology. The purpose of the eye is to see, the purpose of the ear is to hear, the purpose of the lungs is to breathe. Purpose is evident at the cellular level. The purpose of mitochondria is to make energy, the purpose of ribosomes is to make proteins. Purpose is everywhere in living things.
Several of our atheist commentors have a real problem with assigning "purpose" to biology. Clearly, atheists are uncomfortable with acknowledging purpose in biology because it conjures a Source of purpose, which makes them squirm. Always eager to sacrifice science on the altar of ideology, atheists claim that inference to purpose is not necessary to discuss biology.
I disagree.
bachfiend:
The heart is a hollow muscular organ which rhythmically contracts and pumps blood into relatively high pressure arteries, and rhythmically relaxes and receives blood from relatively low pressure veins.
There. I've defined the heart without mentioning 'purpose'.
Havok:
Just because we simplify things by using "purpose" langauge, doesn't mean there is actually any "purpose" there in the sense that you require.Egnor:
it is impossible to discuss biology without discussing purpose.
Havok:
That's rubbish Michael (unless you'd care to demonstrate that impossibility)....
Still waiting for your demonstration of goal directedness/purpose/final causality/Thomistic teleology in biology :-)
OK. Can I demonstrate that it is impossible to discuss biology without invoking purpose? Well, here goes.
Bach was kind enough to describe the heart without explicitly invoking purpose:
The heart is a hollow muscular organ which rhythmically contracts and pumps blood into relatively high pressure arteries, and rhythmically relaxes and receives blood from relatively low pressure veins.But if you neglect purpose, there are other ways to describe the heart:
The heart is red, with yellow fat.
The heart is in a pericardial sac.
The heart weighs about a pound.
The heart moves continuously.
The heart makes a lub-dub sound.
And, oh heck, there are a lot of other things that are just as true about the heart:
It makes a "splat" sound if you drop it from a tall building.
It has no eyes.
It doesn't make urine.
Most people would agree that it wouldn't taste good, even with spicy pesto sauce.
It makes a lousy soccer ball.
It can be used as a paperweight, although it makes the papers soggy.
It can be fired out of a cannon, but it makes a mess.
It has never driven a race car in the Indianapolis 500.
It can be used as a doorstop, although it is rarely used for that purpose.
It can't play the violin.
There are an infinite number of ways to describe the heart, if you eschew "purpose". The heart has never been used as a baseball in a major league baseball game. It can be used to juggle. It is meaty. It would fit in your shoe. It pumps blood. It can't dance. All are equally true, if you are unconcerned about purpose.
So how, pray tell, does a scientist decide which of the infinite number of true facts about the heart are relevant?
Here's how:
Scientists invoke the purpose of the heart.
The heart's purpose is to pump blood.
In fact, you can sum up the main project in biological science during the past 2,300 years: to learn the purpose of things like hearts and DNA and kidneys and mitochondria.
Ironically, bachfiend, in his description of the heart, picked the one description, out of an infinite number of true descriptions, that alluded to the heart's purpose-- and then he claims that the heart can be "defined" without allusion to purpose!
:-/
Even when atheists try to describe biology without "purpose", they invariably select a property out of an infinite number of true things about biology because it alludes to purpose.
It is impossible to discuss biology without discussing purpose. You can't even begin to talk about biology without selecting facts based on purpose. DNA is less tasty than a cannoli. DNA codes for proteins. DNA would make a lousy heat shield for the Space Shuttle. All are true of DNA.
When you talk about DNA, where do you begin? You pick the description of its purpose to talk about it.
The primary goal of biological science is to understand purpose in living things. Without purpose, nothing in biology makes any sense.
Where does purpose come from? Now you atheists can go ahead and squirm.
So how, pray tell, does a scientist decide which of the infinite number of true facts about the heart are relevant?
Here's how:
Scientists invoke the purpose of the heart.
The heart's purpose is to pump blood.
In fact, you can sum up the main project in biological science during the past 2,300 years: to learn the purpose of things like hearts and DNA and kidneys and mitochondria.
Ironically, bachfiend, in his description of the heart, picked the one description, out of an infinite number of true descriptions, that alluded to the heart's purpose-- and then he claims that the heart can be "defined" without allusion to purpose!
:-/
Even when atheists try to describe biology without "purpose", they invariably select a property out of an infinite number of true things about biology because it alludes to purpose.
It is impossible to discuss biology without discussing purpose. You can't even begin to talk about biology without selecting facts based on purpose. DNA is less tasty than a cannoli. DNA codes for proteins. DNA would make a lousy heat shield for the Space Shuttle. All are true of DNA.
When you talk about DNA, where do you begin? You pick the description of its purpose to talk about it.
The primary goal of biological science is to understand purpose in living things. Without purpose, nothing in biology makes any sense.
Where does purpose come from? Now you atheists can go ahead and squirm.
Michael,
ReplyDelete'The heart's function is to pump blood'.
Not a very good definition of the heart. In many species (but not in humans), the spleen contains a lot of smooth muscle in the capsule. In case of acute blood loss, the smooth muscle in the splenic capsule contracts, pumping blood into the circulation (the spleen is a blood filled organ), acting as an emergency blood transfusion.
So equally, you could say 'the spleen's function is to pump blood'. Or ask 'which organ pumps blood? Answer - the spleen.
My definition is more inclusive, including hearts in animals from earthworms to whales.
At least my definition does include what the heart does. Instead of, as you often do, ascribing functions it doesn't have, such as having emotions written in it.
Actually, I've just noticed I've made a typo'. The quote should be 'the heart's purpose is to pump blood', which doesn't make sense.
Delete'The heart's function is to pump blood' actually does make sense, but that wasn't what was written.
Michael,
ReplyDeleteAnyway, I thought you were going to produce some evidence for Thomistic (teleological) evolution. You persist in refusing to do so, insisting that teleology is a metaphysical or philosophic theory, not a scientific theory, and hence not requiring evidence.
OK. Teleological evolution reduces to 'survivors survive'.
That is:
Survivors (if God decides for unknown reasons and by unknown mechanisms to will a new structure or function, or improve a preexisting structure or function, to cope with future changed circumstances, not presently existing)
survive (unless God, again for unknown reasons, decides not to bless a species with teleology, in which case it goes extinct when the circumstances change - as has happened with 99.9% of previous species).
Directed teleology (and Aquinas used the analogy of an archer shooting an arrow at a distant target in 'Summa Theologia') only occurs if a species has some feature not required for survival. A complex 4-chamber heart in an earthworm, for example.
You persist in mischaracterizing Darwinian evolution as 'survivors survive'. 'Survivors survive' applies much more strongly to your theory of Thomistic evolution. Darwinian evolution doesn't necessarily require survival. Just differential reproductive success. Having a lot of offspring, and in particular the offspring having a lot of offspring.
Survival isn't needed in some cases. The female giant Pacific octopus spends the last few months of her life lovingly protecting and tending her eggs while at the same time starving to death. Salmon very rarely manage to spawn a second time, almost all, if they manage to reach the headwaters of their home river, dying of exhaustion (I wonder if that's what my old obstetrics professor meant when he defined epidemiology as the study of man broken down by age and sex).
You don't have a mechanism. You also have no way of telling when it occurs, if it occurs.
Darwinian evolution has a mechanism, natural selection, and it's also possible to determine when it has occurred.
The fitness landscape as a model fits Darwinian evolution. It doesn't fit teleological evolution, despite your claims.
Michael,
ReplyDeleteAt least Thomistic evolution is more 'scientific' than Intelligent Design, which is just 'God did something somewhere somewhen, for unknown reasons and by unknown mechanisms'.
I'll concede you that at least.
Yawn.
ReplyDeleteHoo
bach and Hoo:
DeleteDescribe the eye, without explicitly or implicitly invoking purpose.
This thread is going nowhere fast. How about you return to the discussion of adaptation and reproductive success and address this comment?
DeleteHoo
Michael,
DeleteYou're confusing 'purpose' and 'function'. Function is what has survived the process of natural selection. Purpose is intention ascribed to the structure.
And anyway, your challenge to describe the eye is meaningless, without specifying the species. Eyes have arisen around 40 times during evolution.
Two can play this game.
DeleteDescribe the purpose of the pinky toe.
Describe the purpose of trisomy 21.
Describe the purpose of kidney stones.
And what comedian designer configured the region between our legs—an entertainment complex built around a sewage system?
LOL
Hoo
@Hoo:
DeleteNot everything has purpose in a way we humans recognize as purpose.
But some things do. Where does that purpose come from?
Wait, what? Teleology can't explain such simple things as trisomy 21 and kidney stones? I am sooo disappointed.
DeleteHoo
Why do humans (and most mammals) have 10 fingers and toes? What is the purpose of that?
DeleteWhat is the purpose of the human tail? To remind us that we are monkey's uncles?
What is the purpose of myopia?
Damn, so many questions! So few answers.
Hoo
@Hoo:
DeleteIt's funny that you think of the sex organs as an entertainment complex. Hey, if you're a gay man then your sewer system DOUBLES AS an entertainment complex! How cool is that?
Don't tell me you don't see the design in it.
I think the purpose of the pinky toe is the same as the other toes, to keep us from falling over. But I'm no expert.
The Torch
Hmmm, interesting that the Torch manages to bring up gay sex once again in a thread almost entirely unrelated to it.
DeleteJust get over with it. Try it and report back. Maybe it's not as bad as you think.
I think Torch's observation about the gay entertainment complex and sewer being the same thing is quite funny. An example of evolutionary efficiency.
DeleteMichael,
DeleteWell, actually the reproductive and excretory systems in birds come together externally too. It's called the cloaca. It wasn't deliberately designed.
It happens occasionally in humans. Not by design. By accident. Not funny.
I realize your sense of humor isn't particularly sophisticated.
Michael,
ReplyDelete'When you talk about DNA, where do you begin? You pick the description of its purpose to talk about it'.
But that's assuming that all the DNA has a function. ENCODE might show that anywhere between 20 to 80% of the human genome has a function, to the extent at least of being transcribed into RNA at least once.
Only about 1.5% of the human genome is translated into protein (your definition of DNA 'purpose', represented in just over 20,000 functional genes. There's roughly an equal number of broken non-functional pseudogenes, representing previously functioning genes which have mutated and no longer work. Like approximately half of the 1,000 or so olfactory receptor genes in humans (and all of them in whales).
And then there are the 800,000 or so SNPs (single nucleotide polymorphisms) which mutate frequently enough to give a lot of diversity in the genetics of humans (without having a biological effect), but mutate infrequently enough so that particular ones are inherited in families - and if close to a cancer gene, acts as a marker.
The human genome still contains a lot of junk. Without purpose. However, one man's junk is another man's treasure. Junk DNA is a treasure for geneticists and evolutionists.
bach:
DeleteThe whole question about junk DNA is a question about purpose. Discerning purpose is at the core of biological science.
Why do you persist in denying that purpose exists?
Purpose is in the eye of the beholder.
DeleteDiscerning purpose in biology is a fool's errand. What's the purpose of ERVs?
Hoo
Michael,
DeleteNo. The whole question about junk DNA is function, not purpose.
The core of biological science is defining function. Purpose is arbitrary and can change. The function of eyes is to see. Eyes can be used to read books, so in some people, not all, eyes may have the purpose of reading.
Haha bachfiend, try harder. Teleology is the view that every agent acts for an end. You define the heart as "The heart is a hollow muscular organ which rhythmically contracts and pumps blood into relatively high pressure arteries, and rhythmically relaxes and receives blood from relatively low pressure veins."
ReplyDeleteGuess what the heart's natural end is. The heart acts towards pumping blood into relatively high pressure arteries.
So, perhaps read up on the concept of teleology and try a little harder.
Oh noes! Techne will produce a ton of mind-numbing shit like this. Take cover, y'all!
DeleteHoo
@Hoo:
DeleteCare to address the point that Techne and I have raised?
I see no point worth addressing, Dr. Egnor. You are antropomorphizing evolution and that is hilarious.
DeleteHoo
Techne,
DeleteMichael is pushing the idea of teleological evolution as a competitor to Darwinian evolution.
Evolution is species changing. Darwinian evolution has a mechanism - natural selection - to produce the change.
Michael thinks teleology - a directed process - will produce change. It won't. Teleological evolution would require a feature to be present, but not necessary for survival. Such as a complex 4-chamber heart in an earthworm.
Michael had challenged the realists amongst us to define the heart without mentioning 'purpose'. 'The function of the heart is to pump blood' is OK, sort of. 'The purpose of the heart (in humans) is to allow us (intention) to run a sub-4 minute mile' isn't.
Egnor: It is impossible to discuss biology without discussing purpose.
ReplyDeleteOf course it is possible. Return to the example of adaptation in E. coli that evolved an ability to digest citrate.
Furthermore, one would be hard-pressed to frame that example in teleological terms. Teleology is clearly irrelevant in that case.
Hoo
Bachfiend, evolution is just another term for change. All change is towards some end, be it determinate or indeterminate. An Aristotelian would say change is the reduction of potentiality to actuality. You don't need evolution to be directed towards the emergence of a specific thing over time for the process to be teleological.
ReplyDeleteWhat is so difficult about the citrate munching bacteria? Certain individuals had the potential to metabolize citrate when certain mutations come into being. Those potentialities where actualized through mutation. The mutations may be indeterminate, but that hardly changes the fact that a potentiality was actualized.
ReplyDeleteWhere is the difficulty for teleology?
How does invoking teleology aid in understanding?
DeleteSuppose a system is in state X at time t, and some process F causes the system to be in state X' at time t+1. Then according to teleology jargon the system at time t had the potential to be in state X' at time t+1, and that F actualized it. That's just a word game - it doesn't give any new insights, does it?
This is incredibly funny.
ReplyDeleteAll these atheists spinning like tops to deny that the purpose of the heart is to pump blood, the purpose of the eye is to see, etc.
That's "atheist science" in a nutshell.
Natural processes often act toward ends. Often the ends are purposeful-- an eye sees, and ear hears.
Atheist ideologues are in a frenzy to deny that the purpose of the eye is to see.
Lol.
What's the purpose of the human tail, Dr. Egnor? Everything should have a purpose in teleology, shouldn't it?
DeleteHoo
Hoo:
Delete[What's the purpose of the human tail, Dr. Egnor? Everything should have a purpose in teleology, shouldn't it?]
Not everything is teleological. Coincidences and accidents happen.
Not every teleological thing has a purpose we can cite.
But some things do have purpose.
What, Hoo, is the purpose of the eye?
Hilarious this advanced Egorance.
DeleteTeleology in a nutshell: the baby Jesus must have wanted unless he didn't. Checkmate atheists!
I really doubt any existential questions will be settled by semantic arguments over the definition and applicability of the word “purpose”.
ReplyDeleteWhen communicating ideas to one another we are forced to rely on our vocabularies to create a picture or framework in another person’s mind. In our experience, function and purpose go hand-in-hand, and are quite often synonymous. If we want to communicate information about biological systems, the use of language that implies purpose helps us do so economically using terms easily grasped, nothing more.
It’s a giant leap to make existential claims based on a rigid interpretation of the definitions of words used to try to impart knowledge about systems as complicated as those found in biology. “The purpose of the heart is to pump blood”. That’s great when you’re introducing a child to the subject, but for an adult to use that simple description to justify the notion that the heart was designed to solve the problem of blood flow, or was somehow magically imbued with the desire to be the best heart possible, shows that they simply fail to grasp the subtleties required for true understanding.
The entire conversation strikes me as childish semantics.
-KW
Does the eye have a purpose, KW?
DeleteWhere does the purpose come from?
Michael,
DeleteCurrently I'm using my eyes to read your blatherings. The purpose of my eyes are therefore to read. The purpose comes from me, not from any sky fairy.
You're confusing function and purpose.
And you still don't have any evidence that Thomistic evolution occurs. Unlike Darwinian evolution, which has had over 150 years of research confirming it.
@bach:
Delete[The purpose of my eyes are therefore to read. The purpose comes from me, not from any sky fairy.]
Your eyes didn't have purpose, until you decided they did?
Would they lose purpose, if you decided they didn't?
You still assert that your heart has no purpose. Would you reconsider, and give it a purpose?
Does a person's parathyroid gland have a purpose, if the person doesn't know what a person's parathyroid gland is or does?
Do people's organs gain purposes when people take anatomy and physiology courses?
The theory of evolution suggests that a substance or combination of substances found in the body undergo changes depending on the amount of light impinging on them, and that when by chance, these substances are located such that the nervous system can detect these changes, natural selection does the rest.
DeleteNo purpose, just natural selection taking advantage of proteins that happen to react to light. It’s happened many times.
-KW
@KW:
DeletePerhaps the eye arose that way. Maybe there's more to it.
Do you think that the eye has no purpose?
Michael,
DeleteThe purpose of the eye varies from time to time. The function remains the same. You're still confusing function and purpose.
mregnor: Perhaps the eye arose that way.
DeleteGiven the evidence we can be quite confident that the various types of eyes came arose that way.
mregnor: Maybe there's more to it.
Is there more to it?
What is the "more"?
How would you know if you were mistaken?
This is getting so dumb. Just because a kidney stone has no known purpose doesn't mean that an eye has no known purpose. Is there a reason some people are afraid of the word "purpose?"
ReplyDeleteTRISH
Ms. TRISH,
DeleteDumb is right. A framework that arbitrarily endows some things with purpose (eyes) and leaves others without (human tails) adds nothing to biological knowledge. It amounts to saying "I guess eyes are designed" and calling it a day. Any fool can do that before breakfast.
For instance, I can say that the purpose of the sun is to provide heat for humans. There is no way to prove or disprove that, unless you happen to meet the sun's maker and manage to get a direct answer from him.
Hoo
Hoo:
DeleteYou have made the argument that purpose does not exist in nature.
I have made the argument that it does by showing that you can't even talk about nature without invoking the purpose of things, such as eyes, hearts, ears, etc.
A person who was honest would acknowledge that some things in biology have genuine purposes. Next, that honest person would acknowledge that the question "where does natural purpose/teleology come from" is a valid question.
But of course "honest person" doesn't apply to everyone in this debate.
What's the purpose of vestigial eyes of a true mole? They exist but they don't function. At all.
DeleteHoo
How about the vestigial pelvis of a whale? What is its purpose?
DeleteHoo
Hoo:
DeleteI have repeatedly pointed out that not everything in biology has a purpose. Accidents happen.
That has been a concept central to teleology since Aristotle. Aristotle's classic example of a non-teleological accident is the discovery of a buried treasure by a farmer plowing his field. Other than the discovery itself, everything is teleological-- the treasure was buried (by a pirate) on purpose, the farmer is plowing his field on purpose, etc. But the actual discovery is not on purpose, and is not a teleological process.
Accident and teleology can exist side-by-side.
Some things in biology obviously manifest teleology/purpose, such as the eye. Other things in biology are probably accidents, like some mutations.
Vestigial organs are probably accidental, in the sense that earlier in an evolutionary lineage they did serve a purpose, but due to an accidental event (eg isolation of a population of moles with eyes in a dark cave) they no longer contributed to that animals' survival and (accidental) mutations accumulated that rendered them non-functional. The traditional evolutionary explanation for vestigial organs is fine.
It does not mean that teleology does not exist in other situations, where is obviously does exist, such as in eyes that do see.
Some things (accidents) don't manifest teleology or purpose, at least that we can discern. Other things do.
I have made the argument that it does by showing that you can't even talk about nature without invoking the purpose of things, such as eyes, hearts, ears, etc.
DeleteAnd your argument has been falsified, here in this thread, as numerous people have talked about nature, and even about the specific things you have mentioned here, without invoking purpose.
@anon:
Delete[And your argument has been falsified, here in this thread...]
Be specific.
Hoo,
DeleteSo does an eye have a purpose? Yes or no?
TRISH
It has a function, TRISH. Whether it has a function on purpose, you would have to ask its maker.
DeleteHoo
Egnor: Some things (accidents) don't manifest teleology or purpose, at least that we can discern. Other things do.
DeleteSo your framework arbitrarily divides things into ones that have purpose and ones that don't. It then declares that those things which (in your view) have purpose, well, have purpose. Or something.
Did I get that right?
Hoo
@Hoo:
Delete[It has a function, TRISH. Whether it has a function on purpose, you would have to ask its maker.]
Function means that it plays a role in a causal relationship. The eye, without respect to its purpose, plays a role in all sorts of causal relationships. It serves as a conduit for the blood in the ophthalmic artery to flow into the ophthalmic vein. The eye provides inertance to the movements of the extraocular muscles. The eye provides vision. The eye fills a hole in the face.
The eye has many functions. The function that is relevant (vision) is identified by reference to its purpose.
You can't evade purpose, if you want to discuss the eye.
@Hoo:
Delete[So your framework arbitrarily divides things into ones that have purpose and ones that don't. It then declares that those things which (in your view) have purpose, well, have purpose. Or something. Did I get that right?]
Some things in biology have a purpose. Some probably don't. One of the most important roles of science is to make the distinction, and to discern purpose in organs that have purposes.
Why is that so hard for you to grasp?
Function means that it plays a role in a causal relationship. The eye, without respect to its purpose, plays a role in all sorts of causal relationships.
DeleteNo, that's not what function means. It has a more specific meaning in biology. A trait is functional if it contributes to an organism's fitness. Of course it's tempting* to say that the purpose of a functional trait is to improve fitness, but such language doesn't imply that a designer had any role in the origin of the trait.
*You might enjoy this statement by the famous evolutionary biologist Haldane:
Teleology is like a mistress to a biologist: he cannot live without her but he’s unwilling to be seen with her in public.
The theory of evolution suggests that a substance or combination of substances found in the body undergo changes depending on the amount of light impinging on them, and that when by chance, these substances are located such that the nervous system can detect these changes, natural selection does the rest.
DeleteNo purpose, just natural selection taking advantage of proteins that happen to react to light. It’s happened many times.
Purpose in biology is an illusion, and evolution by natural selection is the theory that explains why.
-KW
Michael,
DeleteSo what is the 'purpose' of DNA? You've previously claimed that it is to be transcribed and translated into protein, but in humans, that only accounts for less than 1.5% of the human genome, since many genes are there to produce RNA as their final product (various tRNA molecules for a start).
What is the 'purpose' of the remaining 98.5%. Including the tens of thousands broken non-functional pseudogenes. And the 800,000 or so single nucleotide polymorphisms, non-functional, free to mutate, but very useful to geneticists and evolutionists.
You've claimed that some mutations are accidental. A photon hitting a nucleotide (I take it, you mean a high energy photon, unless you're one of the tin hat crowd - perhaps you are?). But you've also claimed that nothing happens without the permission of God since He's the 'ground of existence' (whatever that means). Including elementary particles, such as electrons and photons.
So what is it? Are mutations part of God's plan? Or are they accidents? Or are they both? And if both, how do you determine in any particular case which one is happening? It's circular reasoning to assert that if a mutation is 'good', it's part of God's plan, because God is good. Or that if a mutation is 'bad', then it's accidental, because God wouldn't allow something bad to happen (unless as a punishment).
It's sophistry to argue that God is good because he allows evil to occur, from which good could come (as Augustine argued).
And mutations aren't the only changes possible in DNA. Genes duplications and chromosomal fusions also occur. What is the 'purpose' of them.
@KW:
Delete[Purpose in biology is an illusion, and evolution by natural selection is the theory that explains why.]
"Why" presupposes purpose. You can't even deny purpose without invoking purpose.
Pitiful.
@bach:
DeleteYou go off on tangents, and ask a spate of stupid questions.
I simply point out that some things in biology have purposes. It's obvious. The details are of course interesting, but they don't change the fact that purpose is real.
God's role in creation is a matter of theology, which is not the topic of this thread.
I can't stop laughing, because you actually assert that the heart has no purpose.
Michael,
Delete"'Why' presupposes purpose".
No it doesn't. You've claimed that certain mutations occur by accident.
Why did certain mutations occur (such as those causing the eyes deteriorating in cave-dwelling fish)? Answer; by accident. No purpose.
That's actually your reasoning. Not mine.
Your reasoning in attempting to justify purpose is pitiful.
Michael,
DeleteNo. I didn't assert that the heart doesn't have a purpose. I was just providing a definition of hearts in general which doesn't mention 'purpose'.
My definition succeeded. Yours doesn't (and also, as I noted, includes the spleen!)
And anyway, purpose varies. For a considerable number of Australians (and definitely Americans) the purpose of the heart is to supply just enough blood flow to get from the couch in front of the TV to the fridge and back again. For me, the purpose of the heart is to do a sub-3 hour marathon (currently, only in my dreams).
You still confuse 'function' and 'purpose'. Purpose in intention based.
Michael,
DeleteAnd anyway. There are no stupid questions. Just stupid answers, when you decide to give them, or no answers (the usual case) because you don't have any.
Thomistic evolution reduces to 'survivors survive'!
And Thomistic evolution is theology, not science, so theology is the topic of this thread. Thomistic, from Thomas of Aquinas, a theologian, remember?
DeleteI have defined function, purpose, and intention quite clearly.
DeleteI reiterate to spare you the trouble:
Function: participation in a causal chain.
Intention: (Intentionality) the capacity of a thought to refer to something other than itself; loosely, to ascribe meaning.
Purpose: the meaning that is imparted by an intentional act
Bonus definition:
Teleology: the directedness to an end of a change.
I have pointed out that invocation of function in biology is inherently linked to discernment of purpose. Biological things have countless functions. We are interested in a limited range of functions because we infer purpose to these functions.
Now, you define these things.
Michael,
DeleteFunction; what something is capable of doing.
Purpose; what is accomplished, based on function and on what is possible.
Intention; what an active agent sets out to do, based on what is possible. It may be conscious or subconscious.
Teleology; the erroneous idea that it's possible for a function to develop before it's needed - in anticipation. Like the dodo on Mauritius redeveloping the power of flight in the 17th century. Doesn't happen.
You've claimed that ID is true, but also that it's a part of Thomistic evolution. Or if you like, ID is the materialist theory and Thomistic evolution is the dualist theory.
Sophisticated believers, such as Ken Miller and probably Francis Collins, accept Darwinian evolution, but just ascribe a role to God in human evolution. Implanting a mind and a soul (whatever that is) in humans sometime within the last few thousand or tens of thousands of years.
You don't. Why else would you insist that bees and termites must have minds, because they construct bee hives and termite mounds, the most complex constructions on Earth till humans came along?
Or why do you wet your pants about Punctuated Equilibrium? Of what concern would it be to God that a small common widespread marine invertebrate with a shell abruptly (in geological time) goes extinct and is replaced equally abruptly (in geological time) by another small common widespread marine invertebrate with a shell, which is almost identical?
Or as Ken Miller puts, considering God not only to be a serial creator, but also an incompetent serial creator (99.9% of his creations so far didn't work very well and went extinct).
The meanings of the words you've picked are just obsolete based on an outmoded and erroneous conception of how nature is. Aristotle and Aquinas.
Michael,
DeleteAnd applying your definitions of words to your definition of the heart:
The heart's purpose is to pump blood.
The heart pumping blood is the meaning imparted by an act (definition of purpose), which in this case is due to an abstract thought with a meaning not inherent in itself (definition of intention).
Function doesn't get a look-in.
Just meaningless gibberish - gibberish referring to your meanings of the words.
Whereas, in reality, all hearts have the function of pumping blood. Regardless of how complex the species having the heart. And regardless of whether the heart is simple or complex.
Each heart in each species is always appropriate to the species involved. You never get a more complex heart (such as a complex 4-chamber heart in an earthwork) than is necessary, as teleological evolution would require. Never happens.
All you've got is a theory (if theory is the correct word to describe as half (no tenth) baked as teleological evolution) explaining adaptation not evolution.
Be specific.
DeleteGiven that you don't seem to be unable to read, that would seem futile. Every time a poster in this thread discussed biology without reference to purpose, which has happened numerous times, your theory was falsified. Despite your desperate dodging, weaving, evading, and dissembling, that is quite clear.
The person squirming on this thread is you. Atheists have no reason to squirm. They can just enjoy watching you writhe, contort, and dance.