Purple cow fallacy

Curious George said:

I am not sure you can have an invalid inductive argument.

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I think you can...I think if the conclusion is not a viable inductive inference (or worse yet, denies an obviously viable inductive inference) then you have an invalid inductive argument (IMO). Anyway, I actually think that's what the first argument (OP) does...

Curious George said:

Rewritten it reads

1) Some cows are not purple
2) N/A
3.1) If a proof exists, then you know it.
3.2)You dont know it,3c) Therefore a proof of purple cows does not exist.

Conclusion: Therefore no cows are purple.

I think that gets the errors.

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I don't think your rewrite is written right...

My 1st line does not say some cows are not purple is says none of the cows I ever observed are purple

My 2 is not N/A but makes the point that even if someone (like @David T for example) were to claim that purple cows do indeed exist because I have just mentioned the idea of a purple cow and therefore it exists as an idea, I can never hope to actually observe a real purple cow

The third line attests that being that I cannot (even hope to) see a purple cow even if there is one, I can never prove that it doesn't exist any more than I can prove that it does

And the proper inductive conclusion (from 1 and 2 and despite 3) is that since I have observed many, many cows and not a single one has been purple, there probably are no purple cows...

But on RF I often see arguments of the kind given in the OP in which the 3rd line is used to establish a conclusion which is not an appropriate induction. Usually, its just given as a throwaway "prove it" - which of course you can't - but concluding that purple cows exist because we can't prove that they don't is not a valid induction is it?

Suggesting that purple cows probably don't exist because we have observed very many cows and none of them were purple is a valid induction - isn't it?

I have an idea it might be a form of "slothful induction" fallacy. What do you think? In any case, I like the name of that fallacy - maybe I should have had purple sloths instead of cows?

Axe Elf said:

That really goes back past Carl Sagan to Antony Flew's short paper on "Theology and Falsification" in 1950, only he uses an invisible, undetectable gardener rather than a dragon. His thesis was that if a statement is not falsifiable, then it is meaningless--but of course that itself is a fallacy, since statements like "God exists" are not falsifiable, but clearly have a great deal of meaning to those who subscribe to them.

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But isn't the point of Flew's argument that statements like "God exists" are (at least intended to be) assertions - but if I ask someone making that statement to explain why, if God exists, can I not see him, or hear him, or touch him...etc. then I am met with a response that qualifies the assertion and - in this case - to such a degree that the qualified statement is no longer really an assertion at all. God exists but not in the same way that other "things" exist. That is what is meaningless. And it is meaningless because to assert that "God exists" in such a (grossly/grotesquely?) qualified way makes God's existence indistinguishable from his non-existence. What is the use of an assertion that is indistinguishable from its negation? Is it even an assertion any more?

siti said:

But isn't the point of Flew's argument that statements like "God exists" are (at least intended to be) assertions - but if I ask someone making that statement to explain why, if God exists, can I not see him, or hear him, or touch him...etc. then I am met with a response that qualifies the assertion and - in this case - to such a degree that the qualified statement is no longer really an assertion at all. God exists but not in the same way that other "things" exist. That is what is meaningless. And it is meaningless because to assert that "God exists" in such a (grossly/grotesquely?) qualified way makes God's existence indistinguishable from his non-existence. What is the use of an assertion that is indistinguishable from its negation? Is it even an assertion any more?

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Yeah, I would say that's a fair summary of his point. The counterpoint is that even after declaring such an assertion "meaningless," the plain fact is that such assertions still have a great deal of meaning to those who make them. The "use" of such assertions is evident in the effect they have on people's lives.

siti said:

I think you can...I think if the conclusion is not a viable inductive inference (or worse yet, denies an obviously viable inductive inference) then you have an invalid inductive argument (IMO). Anyway, I actually think that's what the first argument (OP) does...

I don't think your rewrite is written right...

My 1st line does not say some cows are not purple is says none of the cows I ever observed are purple

My 2 is not N/A but makes the point that even if someone (like @David T for example) were to claim that purple cows do indeed exist because I have just mentioned the idea of a purple cow and therefore it exists as an idea, I can never hope to actually observe a real purple cow

The third line attests that being that I cannot (even hope to) see a purple cow even if there is one, I can never prove that it doesn't exist any more than I can prove that it does

And the proper inductive conclusion (from 1 and 2 and despite 3) is that since I have observed many, many cows and not a single one has been purple, there probably are no purple cows...

But on RF I often see arguments of the kind given in the OP in which the 3rd line is used to establish a conclusion which is not an appropriate induction. Usually, its just given as a throwaway "prove it" - which of course you can't - but concluding that purple cows exist because we can't prove that they don't is not a valid induction is it?

Suggesting that purple cows probably don't exist because we have observed very many cows and none of them were purple is a valid induction - isn't it?

I have an idea it might be a form of "slothful induction" fallacy. What do you think? In any case, I like the name of that fallacy - maybe I should have had purple sloths instead of cows?

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I think that i am getting confused here. I agree that it is an inductive argument. But if you are asking what fallacies the first one had. The first one seems like inductive reasoning but makes a conclusion. My re-wording was based on the fiest iteration. The first line does claim that some cows are purple. All of the cows the speaker has seen equals some cows. Unless the speaker is claiming to have seen all cows? If that is the case i would lead with that. The second line is speculation. Whether the speaker never hopes to see or believes they can never hope to see purple cows is trivial.

A blind man can never hope to see a cow and a man who is scared of cows never hopes to see a cow. In either case, a person's hopes or future speculation has no nearing on the conclusion. Still it creates measure, allows for rhyming, and is expressive. In t he third point the speaker claims you cant prove me wrong. This is an argument from ignorance that is based on denying the antecedent.

It's just the foolishness of semantics: of being deliberately vague and then blaming the proposition for the absurdity that such vagueness creates. We can prove the negative if we clearly articulate the positive. "X" exists where, and in what way, according to what reasoning. Once we clearly articulate these positives, we can determine whether or not they are being fulfilled.

siti said:

I never saw a purple cow
I never hope to see one
If you can't prove there's no such thing
There certainly must be one

What is the logical fallacy here?

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Thief said:

science believes in dark energy and dark matter

can't see it
can't touch it

BUT MUST BE THERE!!!!!!

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It's a hypothesis, sure. Science doesn't 'believe' in it as such, but rather it's a hypothesis that fits the available evidence.

If you want a more interesting example of how this works, Google how Neptune was discovered.
Compare this, then, to inaccurate hypothesis about Mercury's orbit which were calculated via the same Newtonian theories which accurately predicted Neptune.

It's actually pretty interesting, and a great example of hypothesis being both right and wrong ultimately.

siti said:

I never hope to see one

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there's that emotional insistance

Unveiled Artist said:

Huh?

This is what the OP is referring to. You say something exists by the fact you cant prove that it doesn't. Then compare it to something that does exist we can't see but know as if that automatically supports the existence of something else we can't see or know.

Explain the nature of god as scientists can explain the nature of the universe....

Once you have that then everything else would make sense.

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and science would take us back to the beginning....
a primordial singularity......

start and op?

Axe Elf said:

I can be on the left cushion of my sofa at the same time that I am on the right cushion of my sofa, for instance, by merely sitting in the middle. I can be in both Kansas and Missouri at the same time by standing on the state line. And so forth.

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siti said:

Well OK - but is that really two places? Anyway, never mind - its not really relevant.

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I do think it is relevant though, when trying to solve "Can I be in 2 places at the same time?"
Who am I? Axe considers "I" to be his body in his example. It all depends on "who am I"

Some claim "I have a headache". Hard to prove. If someone says so, I just have to believe
What is real anyway? Someone claiming to have a Head-ache, or others claiming a God-ache
For me something is real when it does not change. Not so much reality using this definition

From Indian Spirituality "Consciousness" is the only reality. Everything is superimposed on Consciousness.
Probably that is why Saints can claim to be omnipresent, because they identify with Consciousness

lewisnotmiller said:

It's a hypothesis, sure. Science doesn't 'believe' in it as such, but rather it's a hypothesis that fits the available evidence.

If you want a more interesting example of how this works, Google how Neptune was discovered.
Compare this, then, to inaccurate hypothesis about Mercury's orbit which were calculated via the same Newtonian theories which accurately predicted Neptune.

It's actually pretty interesting, and a great example of hypothesis being both right and wrong ultimately.

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that's the one item that appears to reverse it's movement?
or was that Pluto?

siti said:

No - you're reading it wrong, the point is there is no hope of ever seeing one because even if one exists (in this case as an idea) its not something that you can see.

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and you're not hoping to see God?

well....I'm not hoping to see dark energy or dark matter
but it's ok if I do

and maybe.....the dark stuff IS God

Curious George said:

I think that i am getting confused here.

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I agree...but apparently not too confused:

Curious George said:

This is an argument from ignorance that is based on denying the antecedent.

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Anyway, I think most people are misreading my intent in the second line - but as someone pointed out maybe its because I was deliberately introducing ambiguity and confusion (these are, after all, essential elements of arguments for the existence...etc...of (for example) God (and other things we can never hope to 'see' because they are not seeable).

I don't agree with your blind man thing - a blind man could certainly hope to see a purple cow (if such a thing existed and was visible) if his sight was somehow restored... I am honestly not trying to be pedantic an persnickety (that comes naturally), but the point I was intending is the non-trivial idea that even a purple cow did exist (for example as an immaterial 'idea'), there would not be any way for me to 'see' it (in the sense of detecting such a thing with my physical senses or any other physical measuring instrument).

Anyway, you are correct (I think - but I might be wrong) that "you can't prove it isn't therefore it is" itself is an argument from ignorance - but the third line is really a premise (one cannot prove the non-existence of something that even in principle is undetectable).

I honestly don't see how the (attempted) conclusion is "denying the antecedent" - there is nowhere in any of the argument that states, claims, asserts...that purple cows either do not or cannot exist.

So here's my own (possibly still faulty) answer to my own question (am I allowed to answer my own question?):

The overall argument is an inductive argument and the fallacy is a form of "slothful induction" because it denies the obviously viable inference from the very strong evidence that no-one has yet seen one or even suggested a sensible means by which one might be observed, that purple cows probably, to the best of our knowledge, do not exist.

Another name for this fallacy is "appeal to coincidence". An example might be:

It walks like a duck, it quacks like a duck...it could be anything...which is to suggest that the waddling gait and quacking are purely coincidental and do not lead us to any viable inference.

Like wise with the purple cow thing...the fact that we have never seen one and have no idea how to detect one if there was one are suggested (by the conclusion) to be entirely coincidental - one still exists.

stvdv said:

I do think it is relevant though, when trying to solve "Can I be in 2 places at the same time?"

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I wasn't trying to solve that question though, I was talking about purple cows.

Thief said:

and you're not hoping to see God?

well....I'm not hoping to see dark energy or dark matter
but it's ok if I do

and maybe.....the dark stuff IS God

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Where is the emoji that shows an idea going straight over someone's head and then kicking the butt of his own ideas?

Anyway, for what its worth, I have written another poem in honour of your contribution - I think the last line especially needs a bit of work :

I never saw a lump of dark matter
Though I hope one day to see some
It really doesn't too much matter
Because I can reasonably infer it is there on account of its gravitational effect on the the visible matter that I can see that cannot be properly accounted for by the existence of the visible matter that I can see and even if it turns out it isn't there it has proven to be a really useful hypothesis that has guided science to some really interesting discoveries that otherwise might have passed us by completely

siti said:

I wasn't trying to solve that question though, I was talking about purple cows.

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Right. Got it.

We have plenty of cows in Holland, but not purple ones (yet). I will get back to you (Deo volente), when they turn purple. I do like the purple color.

siti said:

How did God get into this?

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Some must see God as the metephor for the purple cow in your question?

Only you know the intent.

Regards Tony

Tony Bristow-Stagg said:

Only you know the intent.

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I can assure you, the purple cow knows.

siti said:

I can assure you, the purple cow knows.

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I guess also then that the purple cow also supplies the milk that can sustain life.

At least one can never be blue with a purple cow be happy, be happy, be full of joy!

Regards Tony

Tony Bristow-Stagg said:

I guess also then that the purple cow also supplies the milk that can sustain life.

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That's probably why the stuff tastes so funny these days.

siti said:

I never saw a purple cow
I never hope to see one
If you can't prove there's no such thing
There certainly must be one

What is the logical fallacy here?

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siti said:

That's probably why the stuff tastes so funny these days.

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So are you saying you have tasted milk from the purple cow?

If so, by default have we not proved a purple cow?

Regards Tony