The Raven Paradox, aka Hempel's Paradox

The paradox of the indoor ornithologist. Hempel's paradox. The raven paradox. All of them are names for a bizarre thought experiment that illustrates one of the many problems of induction.

[@charliekowittmusic]

My takeaway from this is that finding a black raven doesn’t hold that much weight to begin with. You can spend 100 lifetimes only finding black ravens. And if a single white raven exists somewhere, all of those confirming instances led me to the wrong conclusion. This is an important idea for considering the bias inherent to our geographical and social bubbles.

[@thehistoryofbeinghuman6597]

"All ravens are black" is confirmed by, for example, finding a red fire hydrant. Is it self-contradictory? No. But I would argue that it is a paradox in the strictest sense you wish to define the term. It is interesting, though, that finding a red fire hydrant also confirms that ravens are blue, green, brown, etc. -- any color of raven besides red is confirmed by finding a red fire hydrant.

[@beatricechauvel8237]

The weight is the reason why it's not a paradox.

[@danielputhawala2008]

Yea, this is one reason I've never really liked this being called "the Raven Paradox". It's not a paradox. It's merely counterintive when framed a certain way. It's just an illusion where your system 1 intuition doesn't actually bear out, similar in my mind to why my students found the de Morgan equivalencies confusing, or why your brain initially jumps to the wrong answer in the following math problem: A bat costs $1.00 more than the ball, and together they cost $1.10. how much is the bat?

[@kellychuba]

I answer 'The balance of Probability, Little Brother'

[@paryanindoeur]

G.E. Moore's _Here is a hand_ might be a bit easier to accept than the Raven Paradox

[@guybrushthreepwood3173]

Interesting. This is certainly counterintuitive, but I'm not sure it is a paradox?

[@danielputhawala2008]

You're correct. Strictly speaking, it's not a paradox. But in OP's defense, he didn't come up with the name. It's a misleading name that's just sort of stuck.

[@Ruktiet]

Fun logic/epistemology video

[@mcleodyoutube7298]

Yes, the false equivalency is that a positive confirming instance is equal to a negative confirming instance. In the same way as seeing a purple raven is a completely different event than seeing a black raven.

[@yesitschelle]

Yeah, he says the instances have different weight. But I don't understand what he's trying to show. Once he got to the set of all non-black things, that made sense to me. Until that, why would it matter if the statements are logically equivalent? Neither can be shown, realistically.

[@Cukito4]

No fallacy here. It only works if the first statement is a fact. And the first statement is not the same as "All black things are ravens." Not, what happens if my 5 year old draws a raven and uses a yellow crayola? She says it is a raven, and draws other birds in other colors. Is it a raven?

[@Jaggerbush]

What's your background? This channel is all over the place. You have no channel description.

[@jeromeblacq7528]

As a black person, it might be a bit hard 😀

[@thinkingcitizen]

I wouldn't say that finding nonblack thing that is not a raven is a "confirming instance" since all it proves is that ravens can be black but not necessarily black... it definitely is one step closer but you'd need to exhaust all things in the universe to prove the original statement, and if it takes an infinite amount of sampling to prove something, then a positive sample is no confirmation-- its basically useless lol not arguing with the logic, just arguing with use of the term 'Confirming' (sorry I was a physics major in college, not a math or philosophy student...)

[@thehistoryofbeinghuman6597]

I agree that "confirming" sounds too strong for a such a weak level of evidence. I didn't feel comfortable with it at first. It seems, though, that this is the way the term is used by philosophers studying induction.

[@QobelD]

Not black is not for even 1 raven. This is logically equivalent to All ravens are black. What you said is not logically sound. Note that the opposite of all, is "not all", or equivalently "not for even 1"and "at least one not" because not"at least one not" is "all." . I assume you are not trying to trick people. (Don't do that with logic and math as an educator) "All" in this case part of the thing "all ravens" so to negate it we say "not for at least one raven" I assure you you are wrong. By your logic. If i make something of wombats i prove that all extrasolar planets aren't made of wombats. This is ridiculous sounding. But making something of wombats that is not an extrasolar planet doesn't prove all extrasolar planets not to be made of wombats. Like if i say "all tables are made of atoms". If i make a chair out of atoms, this doesn't prove all tables aren't atoms. Just as finding a chair that isn't atoms doesn't help confirm "all tables are atoms" either. Reading the comment section here is not surprising. 😅 Logic doesn't always come easy

[@barrow_3490]

I don't see how this is a paradox. It's just acknowledging that experiences which don't disprove a theory tilts you an EXTREMELY small amount towards being more confident. As a method of proving the theory it's useless. Also, unless by definition ravens are black, you cannot claim for certainty all ravens are black. In reality, albino ravens are 1 out of 30,000; so there are a lot - regardless of the colour of my wallpaper.