This Frog is Green Therefore All Ravens are Black...The Problem of Induction?

It’s not really a paradox, it’s just counter-intuitive.

As Burgess said,

“I never saw a purple cow

But if I were to see one

Would the probability ravens are black

Have a better chance to be one? “

When I first encountered the Raven Paradox, it was presented to me as proof that inductive reasoning was flawed. That it led to a best guess, rather than an empirical truth. Consequently, I’d assumed that Hempel was being satirical.

However, the logic follows. If one could observe every colored (non-black) object in the universe and make sure none of them were ravens, he would have established the contrapositive: all ravens are black. Each colored object that is not a raven brings one closer to the goal.

So yes, both Hempel and inductive reasoning are correct. The green frog increases the odds that the statement “all ravens are black” is true.

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Edit (a.k.a. "Oh dear, I'm making this answer even *longer*!")

Re: Whiner48's response

What's so ”dodgy" about induction?

First, as I stated, the "problem of induction" is that it runs counter to intuition. Suppose I walk up to a man on the street and say, "Hey, a red tie! That means all crows are black!" Will he agree? Unlikely. But, as you rightly said, this is a problem with his understanding, not the logic. I was merely illustrating the comic nature of this type of logic.

However, since inductive reasoning is only based on human experience, it is inherently flawed, and I’m not referring to superficial usage of logic. It could very well be true that "all crows are black", but since it is imposiible to observe every crow or every non-crow, how can this statement be empirically verified?

Perhaps there was a *green* crow, but it died ten years ago. How can I observe it? Suppose one in a billion crows is green, but green crows are immediately killed and eaten by their mothers. Would I ever see it? I could observe 10 million crows and still be wrong. That is why I called it a “best guess” rather than an “objective truth”.

Many scientific theories are inductive, and therefore probably wrong. For example, if I had no knowledge of the universe beyond Earth, it would be logical for me to assume that gravity existed everywhere. After all, I have never been to a place where gravity did not exist. Yet we both know my logical assumption would be categorically incorrect.

In short, logic is limited by our limited understanding, our limited knowledge base, and our limited ability to observe. Logic does not exist separately from those who employ it; the logic is flawed because Man is flawed. (And Man is *always* a bit dodgy...)

Your comments?

This type of explanation the explanans gives only a high degree of probability to the explanandum, which is not a logical consequence of the premises. For instance all things not black are not ravens therefore all ravens are black, all ravens are black, all coal is black therefore all ravens are coal.

Circumstance that is not evedencuary to the falsehood of the premises makes the truth of the conclusion probable, but not definite, regardless of a direct corralation between the circumstance and the conclusion? If I understand correctly then this is not infact paradoxical as the existance of the green frog does not counter the premis or conclusion that all ravens are black and would tend to support that things that are not black are not ravens so ravens must be black. An established color variation in ravens would however, prove the conclusion false and so the premis aslo becomes false. That, I suppose falls back into deductive reasoning? Very enlighting question. I will pursue this further. Thank you.

I would agree with most of the things that 'Questionthis' has said.

Correct me if i am wrong, you seem to be ‘hinting’ that there is something 'dodgy' about Carl Hemple's claim. To me logic does in most cases provide the kind of 'objective truth' that we seek. Logic is usually not flawed it is our level of understanding and attitude towards the power of inductive reasoning that is flawed.

A men who uses inductive reasoning superficially is likely to fall in to the trap of stereotyping. Not only would the man draw false conclusions about one aspect of reality but he is also very likely to do the same for other parts of the reality that he was only able to experience them partially.

While induction could offer us quick ways to process and digest information, I try not to get into the habit of using it without giving myself additional premises that could be regarded as ‘exceptions’ by some or most people.

There might not be that many ‘exceptions’ in the things we see in nature but there surely are a lot of exceptions in the things and events we see/experience in the society we live in. Hope my answer makes sense.

********** EDIT **************

Thanks “Questionthis” for your comments.

“……….In short, logic is limited by our limited understanding, our limited knowledge base, and our limited ability to observe. Logic does not exist separately from those who employ it; the logic is flawed because Man is flawed. (And Man is *always* a bit dodgy...) Your comments”

Yes I agree . But I didn’t say that the law of induction itself is “dodgy” I said that perhaps “Nunayer Beezwax” thinks that Hemple’s claim sounds dodgy. Why? Well, “Nunayer Beezwax” said the following:

“The point of the question is...is it the case that instances which neither confirm nor disconfirm the antecedent or the consequent have a bearing on the nomic expectability of the conclusion.”

I have NOT read any of Hemple’s books to be honest, so I am just answering the question from reading whats on this post. Do correct me if I am wrong. What I think is dodgy is the way in which Hemple thinks its “okay” to use one aspect of the PERCIEVED reality as a REFERENCE for LIGITIMIZING the TRUTHFULNESS of other aspects or types of the PERCIEVED reality.

Even if 100% of the frogs that exist or have ever existed on earth were green, what does this tell us about the characteristics of other animals and other parts of our realities? Not that much in my opinion. Its not about whether or not this type of reasoning leads to “objective truth” or “best guess”. Again, consider the following statement made by the asker:

“In other words, it strikes many people as strange that an observation of a Green Frog should raise the level of probability that the statement "All Ravens are Black" is true, however, based on logic it appears this is something that we must accept.”

Yes to me the reasoning sounds strange NOT because it is or isn’t paradoxical but because it has the potential to lead the human mind beyond the scope of the “rational” or “scientific”. Even though Hemple’s original intention was probably to use the claim to support other scientific inquiries of similar nature, I feel he also wants to make his claim a general philosophical claim applicable to other non-science disciplines. If thats indeed the case, I would think the attempt is ludicrous.

It is no doubt a lot easier and maybe more ‘commonsensical’ to use “green frogs, black ravens, grey elephants or whatever attributes a ‘thing’ has in nature that a person perceives to be ‘true’, somehow I find Kant’s idea of “thing in itself” (sth that cannot be know through perception) a more plausible idea for comprehending our social reality. Hope my answer makes sense.

btw what does “nomic” mean?

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Hemple is correct. There's simply Ravens and Frogs here.

There was never a mention of a lake or a dock, let alone

a para docks. I further do not see evidence of a proposal

based on the difference in species.

No, it's correct. The universe includes diverse objects, including (let's say) ten bajillion total objects, including a million ravens and nine bajillion non-black things (with partial overlap). One non-black raven would clinch the matter. One black raven would put us one-millionth of the way closer to the truth. (Since one million black ravens would clinch the matter.) The green frog (as a non-black, non-raven) would put us one / ten bajillionth of the way toward confirming the proposition (that all non-black things are non-ravens).

According to the song by Peter, Paul & Mary, it's "I'm In Love With A Big Blue Frog", not a green frog.

Induction meets requirement.

If the light receptors in your eye see ravens as black and frogs as green, then induction is technically, sound.

However, once the light receptors receive the stimuli of a frog that is not green and a raven that is not black, then the limitations of the induction are revealed.

you have it all wrong dear friend.... not all NAZIS were German and not all Germans were NAZIS.

THAT IS LOGIC! Besides are you so infirm that you have to label everything around you to stabilize your environment? Here is some real help.... if it walks like a duck and talks like a duck.... it is not a raven or a frog.

Better? m'kay

No paridox

Probability not absolute.

Absolute probability, frequency theory, ... In any case, probability hypotheses does not prohibit single events.

chaos. It must never be always

ravens arent black

they are blue and red

nothing to do with paradox...

applying formula to life is about as bizarre as religion