hi everyone Jade here what if I told you that the observation of a white shoe can support the hypothesis that all Ravens are black you'd probably think I was talking complete nonsense right and to be fair that's a pretty reasonable response what could a white shoe possibly have to do with all Ravens being black well this is a video about a phenomenon called the Raven paradox it came about in the early 20th century when a hopeful group of scientists and philosophers were trying to understand the world they called themselves the logical empiricists and as the
name suggests they thought the only things you needed to understand the world were logic and empiricism which is basically observations of the world we all agree on in a nutshell their philosophy was that any meaningful statement about the world could be understood by looking at the world that's the empiricist part and then we could use logic to make conclusions the name the logical in Paris escape their way of understanding the world might be familiar to some of you it's called the scientific method and as you can imagine it's greatly influenced the way that we think
about science but things didn't go as smoothly as they imagined as the Raven paradox soon flew into the face of their needs little method hopefully by the end of this video you'll see that the ways that we go about doing science aren't always as straightforward as you might think to demonstrate this let's take inspiration from the logical empiricism and try to do some science with just logic and empiricism imagine you have the hypothesis all Ravens are black it seems like a reasonable hypothesis to make right so as a logical empiricist what kind of steps would
you take to investigate this hypothesis well to gather some empirical evidence you could go out into the world and simply find some Ravens check the color of their feathers and see if they're black so you do this and every Raven you find is black this is good news for your hypothesis logical empiricism tells us that with every new black Raven you see you should become more confident in your hypothesis that all Ravens are black so now that we've gathered some empirical evidence it's time to introduce some logic basic inference and deduction tells us that the
fact that we've only seen black Ravens support our hypothesis that all Ravens are black we can formalize this logic by saying observing lots of a's with property b supports the hypothesis that all a's are b we can replace a with raven and b with black but we can replace them with anything for that matter and that logic should still hold now we can use the rules of logic to change this statement in such a way so that it is logically equivalent what I mean by logically equivalent is that there could be two sentences that look
different on the surface but are really saying the same thing for example the two sentences I'll meet you at the cafe at noon and I'll see you at the shop which sells coffee when the Sun is highest in the sky one might sound a little bit weird but ultimately they mean the same thing they're logically equivalent to make this clearer it's often really helpful to draw Venn diagrams to help visualize what we're saying let's draw a circle to represent all black things and another disconnected circle to represent all non-black things remember our original hypothesis is
that all Ravens are black which means that assuming our hypothesis is true Ravens only exist in the all black thing circle but if we stop and think about it for a second we can say that it's logically equivalent to say that there are no Raven in the non-black circle for in other words all non-black things are not Ravens all Ravens are black is logically equivalent to saying all non-black things are not Ravens if you're not convinced take a bit of time to let this sink in because this should be a non-controversial statement now can you
think of a non-black non-raven well what about a white shoe it fits the description it's not black it's white and it's not a raven it's a shoe now let's apply some inductive logic take the same formally logical statement from before observations of a with proper DB support the hypothesis that all a's are b we cannot place a with non black things and be with not Ravens so the observation of a white shoe give support to the statement all non-black things are not Ravens but hang on a minute we showed that the statement all non-black things
are not Ravens is logically equivalent to the statement all Ravens are black so we can swap it in without changing the meaning of the sentence and what do we get an observation of a white shoe gives support to the hypothesis that all Ravens are black now I don't know about you but I don't remember the last time a bird scientist published their results on the observation of white shoes and I like to keep up with my bird science but all we used to construct our argument was logic and empiricism so what went wrong this is
the question that puzzled philosopher this is the question that puzzled philosophers of science for years and still does today there are many responses to the paradox but here I'll give the three most well known ones and who knows they may even inspire you to come up with a theory of your own one potential response which our logical empiricist friend Kyle Hempel actually gave is to just bite the bullet and say that an observation of a white-shoe does help confirm the hypothesis that all Ravens are black even if only by a miniscule amount end of story
the advantage of this response is that the scientific method stays safely intact and there is no paradox but it doesn't really gel with our intuition of how the world works philosopher of science Nelson Goodman said that if this approach were true we could do a lot of indoor ornithology in other words we could sit in comfy armchairs and further the study of birds by pointing at colorful objects not only that but if you think about it an observation of a white shoe also helps confirm the hypothesis that all Ravens are blue or green or purple
let's see what other options there are the next response comes from another famous name in the philosophy of science Karl Popper his approach to science can basically be summed up as the job of science and the scientific method is to show whether or not a hypothesis is wrong that's it this idea of showing something as false using observation is called falsifiability and it's what popper thought was the key feature of a scientific hypothesis on the surface this seems like a reasonable way of looking at science it always leaves us open to the possibility that we
might be wrong but if we look a bit closer things get a bit funny remember when we said that many observations of black Ravens would support our hypothesis that all Ravens are black well popper completely disagreed with this approach he thought the business of science was to falsify theories and only falsify them not make us more confident in anything being true an observation of a white shoe wouldn't support the hypothesis that all Ravens are black but neither would a black Ravens to Papa the notion of support or confirmation was not the way science should operate
before we find our black Ravens all this means is that our hypothesis is yet to be falsified this last response I must tell you is the one I agree with most just so you know my biases up front it has to do with the context surrounding an observation let's demonstrate this with some strange but instructive examples imagine you have someone come up to you and say behind my back is a raven would you like me to show it to you you're a bit creeped out but as someone interested in the hypothesis all Ravens are black
you should say yes since if it's a blue or purple raven that would refute your hypothesis Papa would be proud now imagine someone comes up to you and says behind my back I have a black object would you like me to show it to you you figure the people here are just a bit weird so you go to say yes but if you think about it for a minute whatever is behind their back could never refute the hypothesis that all Ravens are black since even if it is a black raven not much would be learned
since you knew the object was going to be black given the circumstance finally a more subtle example imagine a third person comes up to you and says behind my back is a non black object would you like me to show it to you here you should definitely say yes since it could be a blue raven which could refute your hypothesis but if this person pulled out a white shoe in a roundabout way it gives support to your hypothesis that all Ravens are black since given the particular situation a different outcome could have refuted it but
the crucial point to make here is whether or not we care about the observation of a white shoe depends on the wider context if this person said they have an on Raven behind their back then pulling out a white shoe should not matter to you in the slightest since we only care about Ravens whereas you should care if they say they have a non black object since then it has the chance to be a non black raven so the take away with this response is that sometimes a white shoe does add confidence to your hypothesis
and sometimes it doesn't you need more information about how the observation was carried out to make that call so they're just three theories about how the Raven paradox could potentially be resolved the historical development after the advent of the logical empiricist was incredibly fascinating with its fair share of heated disagreements and skirmishes between scientists and philosophers some had more radical approaches to the scientific method like Paul FEA bans total rejection of any kind of universal methodology complete scientific anarchy other approaches like Bayesian analysis were developed and is still being widely used to this day but
that is a topic for another video but the Raven paradox tells me personally is that you can't remove science from the specific context in which it's done even in principle and especially in practice I think this paradox serves as a really good introduction to the counterintuitive intricacies of the scientific method it challenges our assumptions about how science is done and in doing so makes us understand it and hopefully appreciate it over more but I want to know what you think does the observation of a white-shoe support the hypothesis that all Ravens are black let me
know your thoughts in the comments below being exposed to paradoxes and brainteasers like this is great for improving your lateral thinking and training your powers of reasoning but what's even better is trying to answer these problems yourself with today's sponsor brilliant you can do just that their daily challenges are a fun and interactive way to improve your problem-solving skills this one was one of my favorites as I've always been fascinated by the unintuitive nature of probability and how numbers can be so sneaky I found that trying to answer questions is the best way to learn
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get unlimited access to all the brilliance in depth math and science courses head over to brilliant org slash up and Adam to get 20% of their annual premium subscription I'm doing my first-ever live stream to celebrate the channel reaching 100,000 subscribers it's going to be on the 19th of May 8 p.m. Eastern Standard Time I'll also be reminding you guys about it on my social media so make sure to follow me on there as well it would be awesome if you could make it along you'll get to see how awkward I am in real life
when I don't have any prepared lines to say it's probably going to be a Q&A so nothing too exciting if you have any suggestions of things I can do to make it interesting please leave them in the comments below I feel like I need to entertain anyway that's the end of the video thanks for watching bye [Music]
