PHILOSOPHY - Epistemology: Analyzing Knowledge #2 (No-False-Lemma and No-Defeater Approaches)

[@kennethlaino9115]

I was going to say this is weird how all of these videos are basically summaries of the book I’ve been reading. Boy am I dumb to find out that the author is the narrator

[@almasomerville1070]

Which book please?

[@jose_500]

this series is great. thanks, Professor Nagel.

[@vhawk1951kl]

She professes nothing, but rather merely rehearses the best efforts o others, having nothing to propound herself.

[@Ace-dc1yz]

@@vhawk1951kl The purpose of the video is to teach, not to take ownership of the ideas. You would "know" this if you received the info presented.

[@soslothful]

I'm going to stick with the Theory of Epistemology of. "I Said So".

[@Dorian_sapiens]

I prefer the theory of "I think so".

[@Outofontology]

Dorian sapiens I prefer: "It is so, or else I'm triggered".

[@GottfriedLeibnizYT]

Nothing beats the theory of "I Told You So".

[@jobless5866]

Je pense donc je suis

[@soslothful]

@Gavin Naputi Sounds like the end of a relationship..

[@reganheath]

In the Indian gettier case, it is stated that there is no "inference" but surely the person is inferring that their "vision/brain is functioning correctly" and as they are halucinating this is false, thus there is inference from a false belief. Right?

[@sophiejones7727]

correct! lol bad example.

[@rjstoneus]

Regan Heath that's actually an unstated assumption rather than an inference. Unstated assumptions are big problems in reasoning especially when people are unaware of what the unstated assumptions are. Makes it hard to question them. Most of the time people just assume their brains are working normally and don't apply any reasoning to it. The exceptions would usually be prompted by something like say they just took some new medication and he pharmacist told them there was a small chance it could cause hallucinations. Another case would be if someone sees something that appears to be physically impossible.

[@jobecrooks6059]

@@rjstoneus I'm unsure of how it qualifies as just a "Unstated Assumption", but even if it did, wouldn't that therefore no longer be classified as "belief" and would no longer be JTB?

[@pimentejm]

This helped me sooooo much on my epistemology final. Thank you!

[@papercrafts5343]

Because of your profile picture I thought there is a peace of hair in my screen 😂😂 But it turned out that My believe was not knowledge. 😁

[@brokemage1395]

4 years later, it's now helping me with my epistemology final.

[@pneumonoultramicroscopicsi4065]

I don't agree with the "defeater's defeater" example, if you defined defeaters as a hidden fact which you did before, than it's wrong to say that a lie is a fact, maybe the mother confused the student with her lie, but she still had knowledge at some point, if she changed her mind because she was mislead by the mother, than she lost the knowledge, I liked the undefeated JTB theory, I think that it's pretty good.

[@plasmaballin]

Neither of the counter example cases works very well. In the detective case, the detective has enough evidence to justify the belief that a certain person committed the crime, even if some of the evidence turns out to be faulty. The justification is not "All of the evidence is correct," but rather "There is so much evidence that it is extremely unlikely that it is all faulty," which is still a true lemma. Additionally, if it is discovered that that witness is lying, the detective would not automatically discard the other evidence; she would stick with her conclusion unless a large amount of the evidence turned out to be faulty. Therefore, her justification doesn't actually require belief jn that witness's testimony, so it cannot be a false lemma. In the case of the hallucination in the desert, the supposed justification is based on a false lemma, the assumption that the traveler's eyes are not deceiving him. Even if he doesn't consciously think about this assumption, it is still required for his justification to be valid. The belief that there is water is also not basic knowledge. Basic knowledge is knowledge that cannot possibly have a defeater; for example, "I have a headache" is basic knowledge because you can be 100% certain of what you feel. "I see what appears to be water" would also be basic knowledge, but "There is water" would not be because it can be defeated by the fact that your senses are deceiving you. I think the No False Lemma theory and the No Defeater theory are both true because a defeater and a false lemma are really the same thing but defined in a different way.

[@alexanderdavidson7342]

Agreed with both of these points. Quite frankly I'm surprised Nagel used them for the reasoning. And funnily enough I used a headache as an example of basic knowledge as well. For me it's "phenomenal states" that encompass basic knowledge and nothing else.

[@nathanaelmancev3557]

Why can you say "I have a headache" but not "There is water"? Both are propositions informed by sense perception. Why can one be 100% certain of what they feel but not 100% certain of what they see? It seems if one has to say "I see what appears to be water" then they have to say "I have what feels like a headache". If my nerves are unreliable I may be just as deceived by such a physical sensation as that of my eyes/mind by a mirage in the desert, or moreover, just a misinterpretation of my eyes by mistaking a cloud for smoke for example.

[@brycerosenwald2915]

I'm not convinced by the Tom Grabit case for the following reason: The proposition is: "Tom Grabit stole the book." The proposed defeater is: "Mrs. Grabit says that John, not Tom, stole the book." The proposed defeater does not actually defeat the proposition, because the simple fact that Mrs. Grabit says something, does not affect who actually stole the book, or prove wrong our reasoning. We might as well consider: "Mrs. Grabit says that whangdoodles are splendiferous." -- Okay, so what? I don't care what she says, I just want a fact about what actually happened. This defeater would work: "John, not Tom, stole the book." However, this statement is not true, so it is not a defeater. So, I think the whole idea of overlapping defeaters is unnecessary. What do you think?

[@alexanderdavidson7342]

Completely agree. Mrs. Grabit's claim was never a defeater. A defeater needs to be a true fact which hers wasn't. By Nagel's logic, any claim that counters a proposition is a defeater, which is stupid.

[@verywierd61]

@@alexanderdavidson7342 I think Nagel used Mrs. Grabit’s testimony as non-basic knowledge, which she has said to be usually, but not always, good justification. This unfortunately leads the argument in a way to have a hidden assumption that any non-basic knowledge is considered true until proven false. So I think it depends on whether the philosopher arguing the case accepts this hidden assumption. Overall, I think Nagel did not necessarily make a mistake in her explanation, but has merely made her argument contentious because of the hidden assumption mentioned. On a side note, perhaps you shouldn’t be so hasty in declaring that Nagel is dumb. Declaring someone to be dumb requires an objective test like an IQ test to determine whether she has a learning disability or mental disorder. This is quite hard to believe since she is a full-fledged professor.

[@Rikkan4]

So no false lemmas is the no false belief argument correct?

[@cliffordhodge1449]

All these examples ignore the essential indexicality of beliefs formed upon receiving sensory input, beliefs like, "That is water," as opposed to, "There is water ahead." The second seems to be a conclusion based on the first. "That person will get the job, that person stole a book, that person is Tom Grabit." I think a solution needs to consider the myriad indexical beliefs that come into play in forming any belief. In the case of "That is pain," there is arguably at least, no reasoning process, implicit or otherwise.

[@JK-ve9ho]

Thank you so much Dr. Nagel. You saved me.

[@myachantel2345]

I want you as my philosophy professor, Dr. Nagel.

[@popejagged]

I'd imagine that "no false-lemma" could be instrumental, were we to consider that every incorrect inference were omitted - subsequently, only allowing for a straight line of reason from premises to the conclusion. If a straight line of accurate inferences can be constructed without defeaters or false information under that qualification, perhaps it would be salvageable. All false information would thus become irrelevant. On the other hand, there's always uncertainty as to whether or not there are variables unaccounted for which could break that line of reason.

[@virologistic7546]

Essentially Occam’s razor.

[@jonassamek9518]

Those two modification basically follow positivist ideas about verification (in case of non-false-lemme) and popperian fallibility (in case of defeaters), arent they?

[@KozzmoKnight]

I am enjoying your series. I wanted to review epistemology in reference to my theory of quantum ethics. My general thesis of truth is consistent with virtue ethics. I’m always looking for new ideas as well

[@vhawk1951kl]

Whose "ethics"? All that normative guff is no more than relative subjective- and temporary, likes and dislikes- or in plain language, religion.

[@ericwatts8599]

A quick questions about the traveler in the desert that sees water ahead. (I get that his belief about there being water isn't really false because there actually is water ahead where he thinks he sees it). You said that this traveler never made an inference from a false belief, but doesn't he technically infer from his false belief that he sees water that there is water? Or is it because his "seeing" the water counts as basic knowledge?

[@rikardotsamsiyu]

If you don't have JTB, you for sure do not know. If you have JTB, then you still may not know, but your chances go up.

[@Ihadtochooseaname]

I wonder what happens when there is a defeater, but it is specifically chosen so nobody can know about it. For example, tossing the other defeaters aside, if there really was an evil twin and he took over Tom's life, but nobody knows this. For all intents and purposes, that "new" person is Tom now. Does the girl still know that Tom stole the book if she sees him then? I would like to extend the No-Defeaters Theory with this: If you cannot know a defeater exists, or if it does not make any difference in your life if something is secretly false after all, then you know it to be true for all intents and purposes.

[@abdullahhani672]

no, it's not knowledge because after all it's not True.

[@drxyd]

Hidden defeaters should still be defeaters.

[@km1dash6]

Clark's theory seems correct so long as you say "a false premise isn't essential to concluding P is true." In the detective case, if she gathers enough evidence, no one piece of information proves who is guilty. In fact, if the case is iron clad, then it may be that some pieces are false, but non-essential to the final argument.

[@BelegaerTheGreat]

This video offers no explanations. All examples and courses of thought are flawed. 2:11 this is such an incoherent jumble! What if she just did not treat that one person as justification! Her justification would be only the reliable proofs!

[@Doctaviod]

isn't this the same video?

[@ietsbram]

+Winter Wombat a reupload.... again

[@WirelessPhilosophy]

+Bram iets Yeah sorry, we noticed that one of the animations didn't come through the first time and it slipped through our editing process. We just wanted to fix that and reupload it. Unfortunately, the way youtube is setup there is no way (that we know of) to correct the mistake without deleting and reuploading. We have the next video (part 7) in the editing process right now (hopefully without any errors!) and it will be released this coming friday.

[@WirelessPhilosophy]

+Winter Wombat Yes, definitely apologize for the reupload. I gave a fuller explanation down below. Hope it didn't cause too much inconvenience.

[@ietsbram]

Wireless Philosophy np, i didn't even notice anything strange about the original 1

[@Doctaviod]

+Wireless Philosophy a ok, no problem

[@drxyd]

The No-Defeater analysis seems correct. Tom Grabit''s mothers claim that Tom is a 1000 miles away is itself defeated by the students observation of Tom stealing the book. If there in principle exists defeaters for all false claims then whatever remains must be true, so I wonder: Do defeaters always exist for falsities? What if 2 contradictory claims remain undefeated?

[@dennistucker1153]

Well done video.

[@OpenMindedForever]

Who is the Illustrator -- You Professor Nagel or another person? Whomever it is -- my kudos on the polished presentation/art!

[@louxavier2087]

counterfactual. it wouldn't matter. perhaps then knowledge is based on what ever works? But, whatever works for whom? and to what extent and by what means?

[@riveradam]

In the case of the desert hallucination, doesn't the man infer that water is there from his sensory experience?

[@galefray]

Exactly correct; he is basing his 'knowledge' on the belief that all perceptions are veridical.

[@malamati007]

The flaw is accepting SUPPORT for JUSTIFICATION, and I'm surprised that this distinction hasn't been made. Some of the examples (e.g., my seeing a clock face that is consistent with my belief that it's "x" o'clock) accept this as "justification," when it is actually a lower level that I'll call SUPPORT. Sure, the clock face contributes to (supports) my belief that it's "x" o'clock, but it's not sufficient to JUSTIFY my belief. Only a high-quality corroboration (I see the U.S. atomic clock in Fort Collins, Colorado, and "know" that it's not broken, and it's consistent with my belief) truly JUSTIFIES, rather than merely supports, my belief.

[@bentphilips8330]

The question then becomes what IS sufficient to justify a person's belief?

[@Berelore]

I may have missed one but without defining how certain you have to be in your belief for it to count as knowledge any discussion of edge cases is kind of irrelevant.

[@jacobvandijk6525]

I DIDN'T KNOW THAT YOU NEED PHILOSOPHY TO BECOME A FBI-AGENT.

[@wesverr]

In the case of the mirage, I don't think that guy actually has JTB. He sees a water, and there is water under the rock, but there isn't water where he saw it. His believe that there was water on the rock is incorrect. He didn't think there was water somewhere around there. He saw it, so he believed exactly where it was.

[@omnipop4936]

That's what always bothers me about these types of problems. It seems like there's some sort of "sleight-of-hand" going on in the move from, for example, "S believes THAT THING IS A GLASS OF WATER" (which he's wrong about), to the general statement that "S believes that THERE EXISTS A GLASS OF WATER SOMEWHERE IN THE DESERT" (which, turns out, he's actually right about). Seems to me, S's actual belief is nothing more than "Hey, that thing there is a glass of water". Meanwhile, it's our reformulation of this belief as "S believes there's a glass of water SOMEWHERE IN THE DESERT", or "...IN THE HEMISPHERE", or, "...IN THE UNIVERSE" which leads to the problems. We artificially expand his belief to include all sorts of territory (and things that reside therein) which the person really didn't make an explicit claim about anyway. His belief was about a Thing, not the thing's Environment. Same with Smith, Jones, the job and the coins... Smith's belief is simply "Jones, that guy with the ten coins, is getting the job I wanted for myself, darn him." Nowhere does he ponder the comparatively vague, generalized thought that "The person getting the job has ten coins." That's just OUR characterization of his belief.

[@w.a.5101]

How is the previous video from 2021 and this one from 2016? omg

[@vhawk1951kl]

Try it this way: What would be a perfect example of knowledge? Could you improve on as known as when you hit your thumb with a hammer , or that the thing on the end of your left leg is your left foot? - *Anything*short of that obviously cannot amount to knowledge. If 'knowledge is not direct immediate personal experience, what is it?

[@carlossoto9511]

The man in the dessert actually makes one assumption: seeing water doesn't imply there's actually water

[@TheAce736]

Ahh so my comment on the last video is pretty close to the no defeater model. A few thoughts though. I see no point in delineating non basic and basic knowledge, because justifying statements are implicit in basic knowledge too. Take phantom pain for example: The beleif one's hand hurts is based on the false beleif they have a hand in their subconcious mind. Basic knowledge HAS a justifying statement: that the senses are currently relaying accurate information. Furthermore if you stick to the idea that an undefeated defeater invalidates an individual justification itself and not the statement, these example cases are resolved. The desert example, where the ONLY justification (the lying testimony of the senses) is invalid is not an instance of knowledge but true beleif. The detective who has multiple justifications for her beleif, only one of which is invalid, DOES still know and will as long as she has a justification with no undefeated defeaters. I personally see an undefeated defeater as contradicting the definition of a beleif being justified as one cannot reasonably gain knowledge by working on false premises and assumptions.

[@TheAce736]

Following that I'd define a valid justification of a belief to mean the presence of a causal chain between what is beleived and the belief itself, where such a chain is free from any events that if perceived by the beliver would prevent their belief, that itself is not made irrelevant by the the beliver perceiving another event

[@marycarroll7029]

many of the counter examples assume that what they refer to is knowledge, that seems circular, I disagree with the use of "Knowledge" many of the counter examples.

[@marycarroll7029]

Also, the fact that the video ends with "If you like one of these theories" seems to imply that truth is subjective to each person. In that case, is there even truth? Can subjective truth be truth? Can it be true for me that every one's brain is in a vat, and also true for you that we exist in the perceived material world?

[@micahscanz]

Good try

[@frankohrabar5916]

Why is looking at a broken watch at the exact time not knowledge? He knows exactly what time it is... How doesn't he? The clock is not working, but its still telling the truth. Can someone explain?

[@cliffordhodge1449]

Regarding the thoughts on defeaters and defeater defeaters, I dislike the idea that justification for the belief can be saved or rescued by the fact that the believer does not have all the evidence. That seems self-defeating for the attempt to reach knowledge.

[@khaledyasser8293]

I prefer the approach "As long as you define knowledge as TRUE belief then it's impossible because if it were so then humanity has never known anything because we keep changing our minds"

[@Fanterrant]

So i can believe anything until i experience a fact that show me otherwise.

[@jjprempeh2508]

Indeed

[@evad7933]

Gettier did not throw up counterexamples to JTB ...not by my definition of JUSTIFIED. I am an ex maths teacher.

[@RoyBatty03]

Boo Clark. Saying that a. is true as a premise disqualifies one from even being referred to as a philosopher (we're talking logic here, not semantics).

[@SpionCTFT]

Looking at a broken clock is not a justification... Just as useing a broken scale to do experiments would be no good.

[@kemar007]

These philosophers reall loves making a plot twist eh?

[@ΙΩΑΝΝΗΣ-ΠΑΥΛΟΣΚΩΝΣΤΑΝΤΑΚΑΤΟΣ]

Basic knowledge (that can not rely on logic or any kind of reasoning that can be described as statements) has the problem that the subject can have no clue if it is actually knowledge cuz he can have no clue if it is true unless the subject uses some kind of justification that is independent of any statement (so he cant use logic). Having a headache can not be justified without at least the use of logic cuz if logic is not the case anything could be the case !!!

[@god8020]

here is what i think S knows P if and only if 1 P is true 2 S believes P 3 S is justified in believing P 4The justifications are also true

[@RoyBatty03]

I would qualify Hehrer and Paxson as real artistes in the field of mental onanism, wow, and these guys sell books?

[@aurorarose3840]

You are confusing harman's principles with clarks

[@martinjoya4717]

Mala traducción del vídeo.

[@alexanderdavidson7342]

The reasoning here is super really faulty. Firstly, to be a "defeater" the proposition has to be true. Any comment countering a point isn't automatically a defeater unless it's true. Hence Mrs. Grabit's claim that it was the twin who stole the book is not a defeater because it is a false statement. Secondly, to suggest that the guy in the desert who had a vision of water isn't inferring anything is incorrect. He is assuming / believing that he can trust his senses or that his hallucination is veridical (which by definition it can't be). He is having a false belief - he isn't justified in believing there to be water because his justification came from falsity: namely a hallucination. In my mind, we have knowledge so long as our true belief is authentically justified, meaning it is derived from a true premise. In the detective case, when she made her decision, she did so based on the true testaments. She ignored the analogy claim (which was a false claim), otherwise she would've withheld judgement. Or, even more so, that statement by the liar, being false, has no validity because it is not authentic.

[@alexanderdavidson7342]

I'll follow this up by saying radical scepticism is what actually counters all non-basic knowledge exhaustively. But, basic-knowledge defined as "local phenomenal states" cannot be doubted, and hence that's the only thing we can know. My hand is hurting, and I can be sure about that. It doesn't matter if I'm actually a brain in a vat with no hand in that realty. The point of saying "local" is to emphasise that the metaphysical composition of whatever plane of reality we are in now (could be in a dream state) doesn't matter; the semantics of the words relay to whatever this reality is. Hallucinating the pain is also valid, because phenomenal states are a branch of mental states, and whatever their cause (nothing could be affecting my hand) is irrelevant. Therefore, I can know that and that only.

[@magnusjonsson7303]

Knowledge implies Doubt.

[@Zekrom569]

Well i guess that's what we get in software engineering...a lot of gettier cases and long hours of debugging to implement the undefeated solution...

[@michaelchase5304]

5:00 Then the united state of mystics is just "basic knowledge".

[@elijahplummer3655]

My head hurts...

[@ulysses5340]

Mine too.

[@nourtaha3265]

I thought the twin brother was Buck 😂😂

[@judgeomega]

knowledge is just a word. in reality we have encodings with various properties of how it maps to reality. some of it is true, and others are false. some of the encodings have gone through rigorous vetting, others we just accept, and yet others were subliminally injected into our minds.

[@miltonhilario4883]

Are these videos for the religious to justified there irrational superstitious beliefs?

[@darrellee8194]

Seems like all these problems are easily handled by a Bayesian analysis

[@OLDBOYOLDBOYOLDBOYOLDBOY]

you might wanna use words people actually use

[@galefray]

These are all just a play on what "Justified" means.

[@AnRodz]

man, philosophers... take the scientific method and end of story. replication. no matter how justified something is, if it can't be replicated it's not True. if it can only happen Once, then why bother. even if it's replicated, it can always vary depending on a previously uncontrolled variable.

[@dunrossb]

You are aware that it was philosophers who made the scientific method, right?

[@WarOnHorror]

And you are aware that philosophers talked about the real world back when they made the scientific method right?

[@boobella899]

This is so confusing.....wish I was smarter lol

[@Suraj_Rao5]

First. I'm sorry.

[@Nilguiri]

+Suraj Rao First to be defeated.

[@Suraj_Rao5]

+Nilguiri Atleast now you know. (I spent longer than I should have on this comment)

[@sprinvntrdd]

Analyzing Knowledge: Knowledge that has no useful or beneficial application to human kind is worthless and not worth contemplating.