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Author Topic:   The scientific method is based on a logical fallacy
subbie
Member (Idle past 1255 days)
Posts: 3509
Joined: 02-26-2006


Message 1 of 70 (375416)
01-08-2007 3:34 PM


I'm going to reveal science's dirty little secret. The scientific method is based on a logical fallacy.
In the thread entitled Creationism IS a 'Cult'ural Movement!, schrafinator quotes wiki's description of the scientific method, a passable description for my purposes. One of the key defining characteristics of the scientific method is prediction. The more predictions that a scientific theory makes that are borne out, the more reliable the theory is.
There is a logical fallacy called affirming the consequence. It goes like this:
Premise 1 If A, then B
Premise 2 B.
Conclusion Therefore A.
An example of this form would be the following:
If it's raining then the roof is wet.
The roof is wet.
Therefore it's raining.
This fallacy is central to the scientific method. Hypotheses are supported by arguments of this exact form.
If there is gravity then when I drop this ball it will fall.
A dropped ball is observed to fall.
Therefore there is gravity.
Just thought I'd give the creos a little ammunition for their arguments since this place seems to have gotten a bit slow lately.
Cheers!

Those who would sacrifice an essential liberty for a temporary security will lose both, and deserve neither. -- Benjamin Franklin
We see monsters where science shows us windmills. -- Phat

Replies to this message:
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 Message 9 by Dan Carroll, posted 01-09-2007 10:28 AM subbie has not replied
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Admin
Director
Posts: 12998
From: EvC Forum
Joined: 06-14-2002
Member Rating: 2.3


Message 2 of 70 (375433)
01-08-2007 4:43 PM
Reply to: Message 1 by subbie
01-08-2007 3:34 PM


Are you sure this is a correct example of the scientific method:
If it's raining then the roof is wet.
The roof is wet.
Therefore it's raining.
Shouldn't it be something more like this:
Observation: Rain makes my driveway wet.
Hypothesis: Rain makes all things wet.
Prediction: Rain will make my roof wet.
You can test this prediction.
In other words, this may not be a correct reduction of the scientific method to logic:
Premise 1 If A, then B
Premise 2 B.
Conclusion Therefore A.
I think what you've actually attempted to address is the logic for reasoning backward to original causes, and you're absolutely right that the logic you've provided is false, but it would be a poor scientist who forgot that any effect can have more than one cause. Putting it in terms of your rain analogy, there's more than one way for a roof to get wet, and everyone understands that rain is only a likely candidate, not an unavoidable conclusion.

--Percy
EvC Forum Director

This message is a reply to:
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Replies to this message:
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subbie
Member (Idle past 1255 days)
Posts: 3509
Joined: 02-26-2006


Message 3 of 70 (375458)
01-08-2007 6:56 PM
Reply to: Message 2 by Admin
01-08-2007 4:43 PM


The problem I describe comes in the testing of the prediction. As you describe it, the prediction about rain making the roof wet can be directly observed, and thus (apparently) confirmed. However, not all predictions can be directly observed in this way. Take another example:
Observation: Marsupials are the dominant form of mammalian life in Australia, but relatively rare elsewhere in the world.
Hypothesis: Marsupials became isolated on Australia from other forms of mammalian life when the land masses drifted apart.
Prediction: Fossilized marsupials will be found on Antarctica.
The logical structure of this prediction and its confirmation is as follows:
If marsupials became isolated on Australia from other forms of mammalian life when the land masses drifted apart, then fossilized marsupials will be found on Antarctica.
Fossilized marsupials have been found on Antarctica.
This was trumpeted as confirmation of the hypothesis. However, because we cannot go back in time and directly observe the migration, we are forced to rely on affirming the consequence for the force of the argument.

Those who would sacrifice an essential liberty for a temporary security will lose both, and deserve neither. -- Benjamin Franklin
We see monsters where science shows us windmills. -- Phat

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Replies to this message:
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Admin
Director
Posts: 12998
From: EvC Forum
Joined: 06-14-2002
Member Rating: 2.3


Message 4 of 70 (375488)
01-08-2007 8:41 PM
Reply to: Message 3 by subbie
01-08-2007 6:56 PM


The logic *and* the argument you follow in Message 3 has nothing to do with what you offered in Message 1.
I don't mind promoting this as is, it's an interesting topic. Sometimes the best way to think something through is by having a discussion about it. Let me know what you want to do.

--Percy
EvC Forum Director

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subbie
Member (Idle past 1255 days)
Posts: 3509
Joined: 02-26-2006


Message 5 of 70 (375504)
01-08-2007 9:48 PM
Reply to: Message 4 by Admin
01-08-2007 8:41 PM


I'm quite interested to see what other people here do with this. Is it Science? is where I suppose it should go.

Those who would sacrifice an essential liberty for a temporary security will lose both, and deserve neither. -- Benjamin Franklin
We see monsters where science shows us windmills. -- Phat

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 Message 4 by Admin, posted 01-08-2007 8:41 PM Admin has not replied

  
Admin
Director
Posts: 12998
From: EvC Forum
Joined: 06-14-2002
Member Rating: 2.3


Message 6 of 70 (375604)
01-09-2007 9:37 AM


Thread moved here from the Proposed New Topics forum.

  
PaulK
Member
Posts: 17822
Joined: 01-10-2003
Member Rating: 2.2


Message 7 of 70 (375614)
01-09-2007 10:10 AM
Reply to: Message 1 by subbie
01-08-2007 3:34 PM


You've got two problmes here, Firstly a misunderstanding of what it means for an argument to be logically fallacious and second a failure to understand the actual reasoning.
For an argument to be logically fallacious simply means that it is not valid deductive logic. That is the truth of the premises does not guarantee the truth of the conclusion. An argument that provides assurance that the conclusion is almost certainly true is logically fallacious. Since that is the most that science actually claims it isn't that important that it's methods fall short of rigourous deductive logic. (Note that "fuzzy logic" does deal with probabilities and the scientific method could well be valid under those conditions).
So science doesn't rest on pure deductive logic. How then does it work. By considering probabilities. Let us suppose that a theory predicts a certain observation that will be true if the theory is true and true with a probability p if the theory is incorrect. So you have a probability p of being wrong if you guess that the theory is right on one observation. But when you add other observations in the probability goes down. Two such predictiosn and the probability is p^2, three and it is p^3 - and probabilitis can drop pretty quickly.
Let's use an illustration. Suppose someone else is flipping a coin and it comes up heads first time. You wouldn't guess that there was anthing wrong there. Suppose that it comes up heads 10 times in a row. You might start to suspect something there - the odds are worse than 1000:1 against that happening by chance. Thirty times in a row and the odds are a billion to one. Any sensible person is going to get suspicious that there is something not quite right going on at some point in this performance. And every further head will - rightly - make them more suspicious. That's the sort of reasoning you have to address. Cumulative probabilities adding up to one whacking great improbability - not simple examples like the sort you present.

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Jazzns
Member (Idle past 3912 days)
Posts: 2657
From: A Better America
Joined: 07-23-2004


Message 8 of 70 (375615)
01-09-2007 10:17 AM
Reply to: Message 1 by subbie
01-08-2007 3:34 PM


I think where your argument breaks down is in the fact that scientific theories are tentative. You Theory of Roof Wetness does not have the same muster as a complete logical statement but it IS PARTIALLY USEFUL for describing the natural world. If my roof is wet, it likely that it has rained because the other means for my roof to get wet are much less likely than rain.
You mistake is in assuming that scientific theories must be:
1. Complete
2. As stong as a logical statement
Science will settle for, "the best aproximation to reality that we can get at the moment". Logic will not settle for such a thing.
The other problem I have with you OP is that it is often easy enough to provide a counterexample to the fallacy of affirming the consequence. Therefore if there were some science based upon affirming the consequence in a bad enough way then it should be seemingly easy to refute the conclusion.
For example, I could simply wet my roof with a hose as a counter example to my roof is wet => rain.
To invalidate the argument in the case of the marsupial isolation, all one would have to do is prove that marsupial fossils have a wider distribution around the world. Without that evidence, there is no reason to doubt the conclusion.

Of course, biblical creationists are committed to belief in God's written Word, the Bible, which forbids bearing false witness; --AIG (lest they forget)

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Dan Carroll
Inactive Member


Message 9 of 70 (375618)
01-09-2007 10:28 AM
Reply to: Message 1 by subbie
01-08-2007 3:34 PM


I'm going to reveal science's dirty little secret.
I rest assured that this will turn the scientific community on its ear. Someone put Stockholm on speed-dial.
If it's raining then the roof is wet.
The roof is wet.
Therefore it's raining.
Well, the problem here is that the third statment won't be "therefore it's raining." It'll be a lot closer to the following:
If it's raining, then the roof will be wet.
The roof is wet.
All right, now we're getting somewhere.
Is there anything else could have made the roof wet?
Oh, there is? Okay. What else would we see if it was raining?
Maybe water falling from the sky? Somebody check if there's water falling from the sky.
There's water falling from the sky.
All right, now we're getting somewhere.
Repeat as necessary.

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Chiroptera
Inactive Member


Message 10 of 70 (375709)
01-09-2007 3:11 PM
Reply to: Message 1 by subbie
01-08-2007 3:34 PM


Hey, sub. Interesting choice of topic. I wonder how much mileage we'll be able to get out of it?
Part of the problem is that you are confusing deductive logic, the type that is studied in philosophy and mathematics courses, with inductive logic, which is more relevant to science.
To take your example, what we start with is (a slight modification of) your hypothesis, It has rained.
So to test this, we say,
If it has rained, the roof will be wet.
The roof is wet.
Therefore, it may indeed have rained.
What we are really doing is testing the contrapositive:
If the roof is not wet, then it has not rained.
The roof is wet.
Therefore, we cannot conclude that it is false that it has rained.
The hypothesis that it has rained has been tentatively confirmed, pending further studies.
-----
Let's look at another example:
Hypothesis: All ravens are black.
(I like this one, because I try to expose my Math Concepts students to the raven paradox.)
So how do we determine this is true? We certainly cannot examine all ravens. The only thing we can do is,
If all ravens are black, then the very next raven I see will be black.
So then I examine the next raven. It is black. Well, this sure as heck does not prove that all ravens are black in a deductive sense, but it does increase my confidence (a little) that maybe all ravens are black.
So then I look at the next raven. And then the next. After examining 1000 random ravens from different areas from two different continents, I find that each and every one of them is black. Now, from a purely deductive standpoint, I have proved nothing. However, I think that we can see that it is becoming quire reasonable to believe that maybe all ravens are black after all. In fact, we can even begin to put error bars on our conclusion; using relatively simple statistics, we can use the observed fact that, to date, all 1000 ravens that we have seen are black to estimate a maximum for the proportion of ravens that are not black.
Now suppose that we come across a white raven. So now we have a scientific falsification of our simple hypothesis that all ravens are black. We now have to do one of three things:
(1) Find out whether we made an experimental or observational error:
That's not a raven, moron, that's a swan!
(2) Modify the original theory (and then test the modifications):
All ravens are black except those that suffer from white fungus albinism.
(3) Abandon the theory altogether under the weight of contrary evidence:
Out of 1000 ravens in the sample, 700 were black, and 300 were white. I guess that not all ravens are black after all.
-------
Now, getting back to the former example.
If it has rained, the roof will be wet.
The roof is wet.
Therefore, we can tentatively retain the theory that it has rained.
Now, a Biblical anti-precipitationalist can object to this by, for example, positing, the roof is wet because the owner hosed it down. Well, this hypothesis can, itself, be tested. Would the owner have a motivation for hosing the roof (say, as protection of an approaching wild fire)? Do we still see a hose connected to the outdoor tap?
Also, we can further test the original hypothesis:
If it has rained, the neighbor's roof will also be wet.
Also, the trees across the street will be dripping.
And the rutted road on the next block will have mud puddles.
And so forth.
Now these predictions are confirmed, and the anti-percipitationalist offers counter-explanations: the neighbor installed a fire-sprinker system in the ceiling that burst, soaking through to the roof; the trees aren't dripping rain water, they are dripping sap, and the puddles in the next street are because someone on that street has overfilled their swimming pool.
Well, we note a few things here. First, we then go and test each and every one of these counter-explanations to try to find whether they are plausible. Second, we note that the anti-precipitationalist has to come up with ad hoc explanations for a wide variety of data, while the Theory of Recent Precipitation is a single explanation that unites this seemingly unrelated variety of phenomena (this is called conscilience, a good word -- I am currently reading Stephen Jay Gould's The Structure of Evolutionary Theory).
And of course the anti-precipitationalist then points out that the basketball court is not wet. Oops! A potential falsification. Now the precipitationalist must try to come up with an explanation that fits the theory: is the basketball court covered? Is the ground composed of a material that dries out quickly?
Of course, in sight of the bulk of data that supports the Theory of Recent Precipitation, one seemingly contradiction is not going to discount the theory immediately. But it does open up a line of further investigation: can we determine why the basketball court is dry? We might discover something exciting about basketball courts! Or, are there other phenomena that falsify the Theory of Recent Precipitation? Once contradicting data becomes too numerous to ignore, people will start to look for an alternate hypothesis to explain the phenomenon of Widespread Wetness.
----
Heh. This went a bit long. Summary: there is a difference between deductive and inductive logic.
Edited by Chiroptera, : Typos. More than one.

I have always preferred, as guides to human action, messy hypothetical imperatives like the Golden Rule, based on negotiation, compromise and general respect, to the Kantian categorical imperatives of absolute righteousness, in whose name we so often murder and maim until we decide that we had followed the wrong instantiation of the right generality. -- Stephen Jay Gould

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platypus
Member (Idle past 5754 days)
Posts: 139
Joined: 11-12-2006


Message 11 of 70 (375904)
01-10-2007 2:43 PM
Reply to: Message 10 by Chiroptera
01-09-2007 3:11 PM


Musical feathers
So, I think the real answer is that there are many different ways in which scientific research is done. Although the "scientific method" as outlined in the 7th grade science book may be slightly problematic, real scientists take account of how far their results explain.
Example: A researcher was testing the hypothesis that hummingbirds produce a certain noise with their tail feathers during a ballistic dive meant to show off in front of females. He found that four sounds were made during this dive, which corresponded to changes in the bird's posture (wing's extended, wings folded, etc.). The timing of the noises corresponded to the timing of the different postures. The noise he was interested in was the third note. This note was produced during a phase where the bird expanded it's tail feathers into a fan. He wanted to know if the tail feathers produced the noise when they were extended.
The birds produced the noise 100% of the time with all of their feathers.
He cut off the first tail feather, and the birds produced the noise 0% of the time.
He cut off the second tail feather, and the birds produced the noise 10% of the time.
He cut off the third tail feather, and the birds produced the noise 95% of the time.
He cut off the fourth tail feather, and the birds produced the noise 100% of the time.
Now from this you might conclude that the birds used their first two feathers to produce the noise. But he did not do so. Rather, he took the first two feathers off the bird's body, and moved them through the air at the same speed that the bird was moving. He found that the feathers produced a sound at a frequency very close to the observed frequency.
At this point he concluded that the feathers produced the sound in the air. But the first question he got was from a skeptical scientist, asking him how he could not rule out the possibility that the sound was vocalized, by for example removing the bird's vocal cords. Apparently even all his work was not enough to reach his conclusion, since there was still one logical possibility left desptie the strong evidence against that conclusion.

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subbie
Member (Idle past 1255 days)
Posts: 3509
Joined: 02-26-2006


Message 12 of 70 (375934)
01-10-2007 3:50 PM
Reply to: Message 11 by platypus
01-10-2007 2:43 PM


Da yumping frog
Reminds me of an experiment my cousin Sven did a few years ago.
He took a frog and taught it to yump on command. Den he tell the frog to yump and measure how far it yump. Dat vas four feet. Den he cut off one of da frog's legs and tell it to yump again. It only yump tree feet. Den he cut off another frog leg and tell it to yump. It only yump two feet. Den he cut off a tird frog leg and tell it to yump. It yump yust one foot. Den he cut off da last leg and tell frog to yump.
Noting happen.
He tell frog to yump again. Again noting happen.
He got very excited and wrote in his yournal:
"Vit four legs, frog yump four feet. Vit tree legs, frog yump tree feet. Vit two legs, frog yump two feet. Vit one leg, frog yump one foot....
Vit no legs, frog goes deaf."
Edited by subbie, : No reason given.

Those who would sacrifice an essential liberty for a temporary security will lose both, and deserve neither. -- Benjamin Franklin
We see monsters where science shows us windmills. -- Phat

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ShootingStar
Junior Member (Idle past 6269 days)
Posts: 5
From: Germany
Joined: 01-27-2007


Message 13 of 70 (380622)
01-28-2007 4:16 AM
Reply to: Message 10 by Chiroptera
01-09-2007 3:11 PM


Perhaps the roof is wet because a helicopter exercised poor aim while trying to put out a nearby forest fire. Or, maybe gnomes are to blame. Sneaky little bastards!
In any event, I agree with Dan Carroll. Most conclusions require a larger variety of observations to test all the possible loopholes of a theory before it is accepted as truth.
Edited by ShootingStar, : No reason given.
Edited by ShootingStar, : No reason given.

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ShootingStar
Junior Member (Idle past 6269 days)
Posts: 5
From: Germany
Joined: 01-27-2007


Message 14 of 70 (380623)
01-28-2007 4:17 AM
Reply to: Message 10 by Chiroptera
01-09-2007 3:11 PM


Kein Problem
chiroptera wrote:
we can tentatively retain the theory that it has rained.
Now, a Biblical anti-precipitationalist can object to this by, for example, positing, the roof is wet because the owner hosed it down
What's wrong with rain?

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Chiroptera
Inactive Member


Message 15 of 70 (380659)
01-28-2007 9:30 AM
Reply to: Message 14 by ShootingStar
01-28-2007 4:17 AM


Re: Kein Problem
Biblical anti-precipitationalists claim it contradicts the literal account of Widespread Wetness as it is written in their scriptures. It also removes God from the picture. That is why they want "equal time" and include the "Intelligent Bedwetter" theory into the public school curriculum.

This world can take my money and time/ But it sure can't take my soul. -- Joe Ely

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