In the West, Aristotle put it as follows: "To say of what is that it is not, or of what is not that it is, is false, while to say of what is that it is, and of what is not that it is not, is true"
Some 2 millennia later, Tarski, a Polish logician, more or less formalised just that. This result, among other things, spawned a brand new branch in mathematics: Model Theory. More on Tarski’s notion of truth: https://plato.stanford.edu/entries/tarski-truth/. A few decades later some analytic philosophers like Davidson drew on Tarski’s work and applied it to natural language, too. This resulted in this: https://en.wikipedia.org/wiki/Truth-conditional_semantics. But notwithstanding Tarski’s work, there’s still significant controversy surrounding both “truth in natural language” and the logico-mathematical truth predicate in philosophical circles. Here’s an article that covers axiomatic theories of truth in general: https://plato.stanford.edu/entries/truth-axiomatic/.
In the real world it is impossible to find human experiences that are "causally linked" to facts in the world, and so the implication of the argument is that EVERY experience you have ever had is possibly like looking at the broken clock.
And yet, most of us would believe that there is a difference between looking at a broken clock that says noon, versus a working clock that says noon. It would be nice to have a rigorous way to distinguish between the two cases - solving that problem might teach us something about the world.
"Knowledge" is just a word. It references many different concepts.
> In the real world it is impossible to find human experiences that are "causally linked" to facts in the world
Either you've misunderstood what causal linkage is, or else you are some odd brand of solipsist, but either way, this is incorrect. Causal linkage just means that that event participated in causing this event. The sun being in the sky is causally linked to me believing it's day time, for example.
> And yet, most of us would believe that there is a difference between looking at a broken clock that says noon, versus a working clock that says noon.
Of course there is. In one case, your belief is causally linked to fact. In the other case, it isn't, but still happens to be correct.
Great example! In Ptolemy's time "the sun being in the sky" would have meant that the sun was in a particular phase in its orbit around the Earth. Now we understand that the sun is not actually "in the sky" but it is a hundred million kilometres away. Our understanding of what it means for the sun to be "in the sky" will likely undergo several revolutions in the next 100,000 years.
Second, the actual facts are not causally linked to your belief. Your perception that the sun is in the sky is causally linked to your belief that it is daytime. If I am a schizophrenic and I hallucinate that the sun is in the sky even though it is night time then do I "know" that it is daytime?
All of this probably sounds overly pedantic but teasing apart the details is exactly what we're trying to do here :)
> Our understanding of what it means for the sun to be "in the sky" will likely undergo several revolutions in the next 100,000 years.
I wouldn’t bet on it.
> Your perception that the sun is in the sky is causally linked to your belief that it is daytime.
My perception is cause by electrical impulses from my eyes, which are caused by photons hitting those receptors. The photons themselves are caused by the sun, and their incoming vector is caused by its position relative to me. There is a causal chain, thus, causal linkage.
> If I am a schizophrenic and I hallucinate that the sun is in the sky even though it is night time then do I "know" that it is daytime?
Depends on what you mean by know. Your perceptions are not causally linked to a true belief, if that is what you are asking.
Replace software with language, class with concept we use to refer to facts and you have to claim that any further thought into the design of your class is wasted, because you hold that to be the case for concepts, language and reality.
But I was under the impression that philosophers thought themselves more than mere dictionary debaters. Whenever I hear about this problem, my impression is that at least non-zero of them think there is a problem with the actual concept of knowledge, not merely the word.
Obviously, none of us can ascertain truth directly. The only way we can claim A or B is true is by appealing to some justification for our belief. Therefore, the idea that [knowledge = true and justified belief] collapses to [knowledge = justified belief].
From that point, we have only to discuss what constitutes better/worse justification(s).
And that leads to relativism, which we don't want.
The classic "Rationalist" (as in Kant) explanation of mathematics is that things like pi are an a priori concept, or phenomena. An ideal if we will, that is innate within us that helps us to explain the reality without (the noumena). Mathematics relates to the interrelation of these concepts. Physics is a (very successful) attempt to relate these apriori phenomena concepts directly to the noumena.
Again, just a have-a-go layman on the philosophical front as well and I welcome any corrections or more sophisticated elaborations!
There is a world out there. This reality, universe, or whatever, is in some state or another, works in some way or another, and whatever we think about what it is or how it works has little bearing on what it actually is, or how it actually works. "Truth" then is merely an accurate depiction of our world (or parts thereof). The problem is ensuring accuracy, and that is impossible without infinite evidence. We can only approach certainty.
And there is indeed a point where we are certain enough, and further inquiry isn't worth the hassle.
We are a part of this world, so if you accept that you must accept that how you think about the world is a part of the definition and state of the world itself.
Which quickly leads to the conclusion that it is impossible to reason about a system from inside the system with absolutely certainty.
Hence "little", instead of "no".
I believe I can make it a non-problem by defining some new words.
Belief - a thing one thinks is representative of the universe
Knowledge - a thing one thinks is representative of the universe, with justification
Billabooknowledge - a thing one thinks is representative of the universe, with justification, that turns out to be wrong, despite one not being aware it's wrong
I.e “you know it is noon” means you can predict that when you look outside the window it will be light, the church bell will be ringing, the clock will point to 12 etc. One or more of these corroborating factors provides that knowledge to you (eg you can still know it’s noon if the clock is broken because you can hear the church bells and see the sun above your head etc)
"Better prediction" requires evaluating a truth claim, so this viewpoint would seem to contradict the rejection of truth.
As Mac pointed out in IASIP: Reynolds vs. Reynolds, you need a leap of faith to accept all the sciency writings about subatomic particles and whatnot.
For example:
* As of writing this comment, I have five fingers on each of my hands.
* Humans must stay hydrated to survive.
* Within my office, the time is currently 4:45 +/- 1 minute.
Those are truths, though there may be pedantic holes in my communication.
Well, if you are not a brain in a jar, maybe. As far as I am concerned, I don't have any undeniable evidence that you even exist, nor that I have hands.
That's a pretty useless kind of skepticism, but as long as you are going for objective "truth" you must face that kind of problem.
If I am a brain in a jar, do I have hands?
Well, then I would still have virtual/simulated/apparent hands. And, when I say "hands", by that word I mean those virtual/simulated/apparent hands. Hence, even in that scenario, I do indeed have hands.
The ordinary meaning of the English word "hands" encompasses both "ultimately physical hands" (of the kind I might have if I am not a brain in a jar and also not some AI living in a computer simulation) and also "simulated hands" (of the kind I might have if either of those hypothesises were true). So, either way, it is true that "I have hands". When I say that, I am not expressing any opinion on the truth or falsehood of those sceptical hypothesises. If I wanted to express an opinion on those sceptical hypothesises, I need to explicitly exclude them, i.e. "I have ultimately physical hands".
For instance, I have 5 fingers in each of my hands: you see them, you use them, so they must exist and be real. I’m no philosopher, but I suspect their arguments would go towards how can you trust your senses and perception to prove ideas about reality...
It's a bit like arguing "I" don't move my arm because neural signals trigger muscles to move the arm. Both are true, the language is just more involved if we don't share a common definition of "I".
Though, this is a good example of what I meant by precision of truth. "I observe five fingers" is more accurate, and there are still better phrasings, but individual inability to precisely communicate truth does not imply truth does not exist.
We understand what hands are, but imagine trying to write a program that infers what hands are, and works automatically for non-humans as well.
And then it has to work for people who don't have five fingers, too.
There are a lot of assumptions embedded in words. None of these are generally interesting, which is why they're best ignored. But they exist.
This seems like saying, "The truth is that there is no truth." Or the truth is that there is a set of models which are more or less the case and this meta-model is the actual truth. In both cases, the argument seems to implicitly rest upon the truth, or a belief of the nature of truth without getting out from under the thing that the argument attempts to deny. How can we talk about there being no such thing as truth without it turning into a sentence like:
This statement is false?
I guess I’d say is person and time dependent. Perhaps you agree and would say there is no such thing as objective truth?
This person has a very strong belief, so strong that they put the label "truth" on it. But that's a different meaning than the word has had in this discussion thread - so different that different words should be used, to keep us straight. The version you mention here might be called "strongly-held belief" - held so strongly, in fact, that the person holding it can't imagine that it could be questioned, let alone false.
But for the rest of the comments, I think that people are using "truth" to mean "correspondence to reality". I think that that is quite different from "strongly-held belief", because I don't think that strongly-held belief changes reality.
For me a strongly held belief is more or less equivalent to truth for the person who holds such a belief.
The truth is a telescope of verifications that trace back through history. It's not a personal thing. It doesn't stop at your skull.
Incidentally, the only time I ever hear people saying truth is relative or doesn't exist is when those people are simply trying to promote their own social standing or take advantage of people.
The fact that two people disagree about something does not automatically imply that they are both wrong, only that at least one of them is.
I've slowly been converging upon the belief that there's no such thing as "truth". There are only models and predictions, and some models lead to better predictions than other models. (What then is a mathematical truth?)
For the clock example, "knowing" whether it's noon or not is useless in the framework of prediction. You instead develop a model with two (probability-weighted) possibilities: 1) the clock is broken and thus can't be relied upon as a correlate with other events or 2) the clock is functioning and this information can be utilized in some way to improve future predictions. From a utilitarian perspective, what value does knowing the absolute "truth" about the state of the clock add?