[quote]hlss09 wrote:
I guess then I coiuld say that 2+2=4 or dogs can break dance. I mean, by definition this disjunction is true, b/c 2+2 is true and I’m justified in believing it. But, what if I KNOW that dogs CAN’T break dance?
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yes, you could indeed say that either 2+2=4 or dogs can break dance.
you could also say that either 2+2=4 or 2+2=5 (and that would be a JTB / knowledge).
i do get that this maybe sounds a bit odd… perhaps this helps –
either i will or i won’t.
?
(i do get that there is something odd about the above. but i also get the intuition that that just is the way things are. sometimes the way things are is slightly infuriating. maybe it is odd because we think of deduction as something where we are taking a subset out of a greater set in getting a conclusion out of premisses whereas the above type thing seems less about that and more about introducing irrelevant stuff that obscures. i’d like to suggest that problem is in IMPLICATURE rather than DENNOTATION (grice))
[quote]hiss09 wrote:
It’s one thing to deduce something on a false premise, but another to intentinally place a disjunct that you know to be false, correct, or not?
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well…
intentionally placing a disjunct that you know (or believe) to be false … i don’t know that that could happen in a Gettier style case. what would that look like?? ‘i believe that brown owns a ford except that i don’t believe it?’ (moore’s paradox). we needed the initial belief that ‘brown owns a ford’ to kick things off and believing it means… believing it to be true (slightly controversial but pretty widely accepted).
[quote]hiss09 wrote:
As far as the false premise argument: Gettier talks about a guy in a park. The guy sees a dog standing in the park, and says to himself “there’s a dog in the park.” He’s obviously justified in this belief - he sees a dog, etc. He is justfiied. But, as it turns out, that dog is actually a robotic hologram. Additionally, however, there IS a dog behind a tree, out of the man’s line of sight. So, his belief that there’s a dog in the park is technically TRUE, but it’s based on a deduction that relies on a falsehood. This example disproves that knowledge can result from a falsehood…
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haha.
so the justified true belief theory of knowledge (JTB) was fairly widely accepted as alright for quite a while…
the justified true belief theory of knowledge maintains that there are three individually necessary and jointly sufficient conditions for propositional knowledge. it is true that subject S knows that proposition P if and if (when and only when):
- S believes that P
- S is justified in believing that P
- it is true that P.
then this unknown philosopher called gettier got the thumbscrews placed on him since he hadn’t really done any work for a number of years… so he wrote up a tiny little two page paper in which he purported to show the JTB theory of knowledge to be hopelessly inadequate.
he claimed to describe cases where the 3 conditions obtained but where intuitively we would not at all want to say that S knows that P.
Steve Stich (Rutgers) did some cross cultural research and found that Gettier intuitions (the intuition that S does not know that P in the cases Gettier describes) are far from universal. people from eastern cultures often say ‘yeah so smith knows that either jones owns a ford or brown is in barcelona’ yeah. it tends to be western people who get good grades in western philosophy classes who get the intuition that there is something outrageous or wrong going on.
i don’t have Gettier intuitions. that is just to say that in both the cases Gettier describes I’m like ‘sure, they know that. no prob. jtb theory of knowledge good enough for me. not perfect. but, what, you expect the natural language word ‘knowledge’ to be less rough round the edges than this??’
but anyway… guy in the park (got distracted, sorry)…
think descartes…
i seem to see a dog. yes he does. indubitable.
is it justified to believe what you perceive??
most people think yes. it is justifiable to infer the presence of a dog from the perceptual seeming.
i mean consider the alternative…
if it isn’t justified for us to believe what we (seem to) perceive then most of our beliefs about the external world (those formed on the basis of seemings) would turn out to be unjustified. we wouldn’t know that there is a computer in front of us or that we were even awake or whatever.
so the step of inference for knowledge cannot be so stringent as certainty. (not if we want to have knowledge).
but if the step of inference for knowledge isn’t that stringent… if there is some uncertainty… then there is going to have to be some error. not with regards to the truth of what is known (though some think we can know things that aren’t strictly true - but that is tricky)…
i suggest we suck it up and go ‘yeah okay so these crazy convoluted cases that very rarely happen IRL get to be cases of knowledge’.
or…
you could do what was popular in the 60’s… try and think up a 4th condition that serves the purpose of ruling out gettier cases as cases of knowledge but not having it too strict since we probably want to get to count as knowing some empirical things…