The value of Truth is not absolute because new facts can and have changed the truth value of previous claims. So a true belief can be prove not true...while an instrumentally valuable statement can always be used as knowledge. — Nickolasgaspar

A good post. Like you, I take a pragmatic view of knowledge.

Calling all knowledge belief justified to be true is an imposed (made up) criteria, desiring certainty before looking at how various kinds of knowledge actually work. Science is not justifying beliefs; it is a method. — Antony Nickles

This made me think of one of my favorite quotes from Stephen Jay Gould, a great science writer—In science, ‘fact’ can only mean ‘confirmed to such a degree that it would be perverse to withhold provisional assent.'

@Jamal—I am so f...ing tired of this em dash, but I don't seem to be able to stop using it.

We totally agree on that. After all the ideal state of a concept is an observer's creation which in practice he/she strives towards it. (truth, knowledge etc).

How should we define 'knowledge'? — Cidat

I don't think there's a perfect, single definition of "knowledge". However one tries to create such a single definition, one will necessary leave out things. It can only be defined in a context.

Moreover, the word "perfect" alone makes such an attempt impossible. Perfect means or implies "absolute" and nothing can be considered "perfect" or "absolute". We can only use such words figuratively and for description purposes. There's no actual "absolute zero", even if this a scientific term. It refers to measurement and thus it depends on the method, conditions and means with which we are measuring it.

Experience is both knowledge and meaning, being strictly the property of a conscious subject and never does it belong to the world of objects.

This made me think of one of my favorite quotes from Stephen Jay Gould, a great science writer—In science, ‘fact’ can only mean ‘confirmed to such a degree that it would be perverse to withhold provisional assent.' — T Clark

Gould spoke where I went to school at Willamette about rapid evolutionary changes. When someone asked about creationism, he started yelling at them (as if they were perverse). The point about science is that it does not need assent. The method could be done by anyone and the results are the same. Your moral claim on me needs to be acknowledged by me (or rejected). You swear allegiance to a country. But we do not agree about science (disagreeing with someone's science is to say it was done poorly). Now you can ignore science's facts or exagerate their significance, but those are political moves, not scientific ones. Gould is right in saying science is confirmed; and this just means we've done the same experiment enough times to be sure it wasn't a fluke, not that we are confirming our hypothesis against anything--"the world" or "reality".

So, again, to say my belief (opinion, theory, etc.) is justified (say by the facts of science) does not make it a higher order of belief, now deemed "knowledge". It's just a statement of fact; the only relationship to belief which it has is the kind of belief that is a guess, to which the fact is an answer with certainty--"I believe it's raining out" "Well, let's go and look and we will know". But there are other senses of belief that are not just uncertain guesses, such as "I believe in my son".

Knowledge is experience and meaning.

The science behind many human actions is however, provisional and, as earlier posters like T Clark have suggested, pragmatic. The relation between serotonin and depression for instance is unclear but doctors largely accept that ssri's are likely to benefit their patients. Science in this sense is a body of knowledge with varying degrees of 'certainty' or likelihood. Whereas there are matters in the emotional domain - whether a certain person loves me, for example, or I love them - which I know a great deal more confidently than I know there's a causal relationship between serotonin uptake and depression. I know through my body, which includes my brain. Other people's fancy formulations about j.t.b. do not necessarily impinge on me at all, though when we talk with one another, some sort of justification, and some notion of truth, are bound to be central.

When someone asked about creationism, he started yelling at them (as if they were perverse). — Antony Nickles

I am a big fan of Gould's, but I understand he was something of a jerk sometimes. Being something of a jerk myself, I don't hold that against him.

The point about science is that it does not need assent. — Antony Nickles

That's the thing about knowledge—if you can't use it, it ain't really knowledge. In order to use it, you have to assent with it, accept it.

So, again, to say my belief (opinion, theory, etc.) is justified (say by the facts of science) does not make it a higher order of belief, now deemed "knowledge". It's just a statement of fact; the only relationship to belief which it has is the kind of belief that is a guess, to which the fact is an answer with certainty--"I believe it's raining out" "Well, let's go and look and we will know". — Antony Nickles

I'm taking a pragmatic approach to this, while you seem to be taking formalistic, linguistic approach. Information has to be known, factual, justified, understood, believed, assented to before it can be used. The only interesting thing about knowledge is that we can use it to make decisions.

The only source of knowledge is experience and meaning to biological consciousness. For biology is the measure and meaning of all things. A conscious subject is the sole holder of meanings and thus knowledge.

So sayeth the wise one once more but this time he is even more wrong !!!

So what is the perfect definition of knowledge? — Cidat

Definitions do not work in that way.

You know that there are two ways to approach definitions, by stipulation or by description, and that definitions by stipulation set out how one ought use a term, while definitions by description set out how one actually does use a term. That difference in approach is found between Webster's and The Oxford dictionaries. Which is perfect? Well, it depends on what you are doing; hence, neither is quite perfect.

The "justified true belief" stuff comes from Plato, but even he wasn't happy with it, ending the Theaetetus in aporia. Still, some folk like it, and as a working definition it has its uses. The Gettier examples serve to show that treating justified true belief as a stipulated definition is fraught with difficulties.

The most common problem hereabouts comes from those who confuse what we know with what we believe. It should be apparent that we can only know things that are true, whereas we can believe things that are false.

So one cannot know something that is not true. Additionally, if you know something, you know that it is true, which is just another way of saying that you believe it. One cannot know something one doesn't believe to be true.

On this last, one might well express surprise or incredulity by saying one knows such-and-such, but "I don't believe it!" That's a turn of phrase rather than a counterexample.

So if one knows something, then that something must be both believed and true. Hence the "True belief" part of the justified true belief account.

The "justification" part comes from our not being able to know stuff that does not fit in with our other knowledge. What we know has to be consistent - and if it isn't something has gone wrong.

So 's amusement is to some extent misplaced. Perhaps coming from outside of philosophy he doesn't see the issues that the JTB account is actually addressing.

And it's not hard to see problems with defining knowledge as "useful information". We all know stuff that is not useful, unless one is going to specify utility in such broad terms that anything is useful—at which point being useful becomes moot. And there is useful information that is false - Newtonian physics, for example.

Philosophy is, generally speaking, a lot harder than it perhaps seems.

A last point to note is the difference between what knowledge is, as given by this or that definition, and how we "find a solid way of forming knowledge". JBT is not a method for deciding between competing beliefs.

Anyway, that might go some way towards broadening the discussion here beyond mere utility. Cheers.

A good account. Any decent discussion of knowledge needs not only to acnowledge, but account for, the relation between knowing that... and knowing how... Seems to me that knowledge as demonstrated application does this quite naturally.

One historical mistake certain philosophies have made is this search for certainty instead minimizing error for a purpose. — Richard B

And another mistake is to suppose that we cannot be certain of anything. On Certainty shows this clearly.

...truth and knowledge are observer relative evaluations, limited by our current observations. — Nickolasgaspar

I don't see how to make sense of this.

If we decide that something is true on the basis of some observation, and subsequent observations show that it is not true, then we were wrong.

Our observations do not generally change what is true, but what is believed.

Good stuff from Banno. I've never managed to form a strong opinion on knowledge. Still don't know what line to take.

Here I think being simple-minded or naive may be of some help. What definitions, outside of those given in mathematics, is a complete or at least satisfactory definition of any word?

What is a chair? What is life? What is an animal? What is a thing?, etc.

We soon realize that we can quite significantly expand most definitions way beyond anything given in a dictionary. And more curiously still, we frequently are aware when a person is misapplying a word.

To that extent, what's the use of defining knowledge? Does something significantly change in your view of the topic if it is defined one way as opposed to another?

Given that sticking to JTB's cause more trouble than clarifications, I think the ordinary phrase "he/she knows a lot about X", where X can be almost anything: farming, cars, history, laptops, etc., is quite comfortable and does not bring forth much problems, so far as I can see.

So ↪T Clark's amusement is to some extent misplaced. — Banno

I didn't say it is amusing, I said it is silly. Not the same thing at all.

And yet, as explained, if something is known, it cannot be false, it cannot be disbelieved, and it perhaps cannot be unjustified.

Not so silly? But amusing, if this thread continues.

So ↪T Clark's amusement is to some extent misplaced. — Banno

As is your wontmodus operandi, when I contradicted your statement and provided evidence, you changed the subject.

[Edit] Note change in text.

I was simply seeking a more forthcoming response to my post. Oh, well.

I was simply seeking a more forthcoming response to my post. Oh, well. — Banno

Your post was your usual passive-aggressive snot, as is this one.

Damn, is on to me, despite my cunningly hiding my passive aggressive snot in an account of justified true belief.

Damn, ↪T Clark is on to me, despite my cunningly hiding my passive aggressive snot in an account of justified true belief. — Banno

As I wrote previously, I think JTB is silly, but I do believe my judgement of your post is true and that I'm justified in believing it.

Damn, ↪T Clark is on to me, despite my cunningly hiding my passive aggressive snot in an account of justified true belief. — Banno

This is fun, but we're unnecessarily cluttering up this thread. I'll let you have one last at bat if you'd like. That's baseball terminology. You can ask @Noble Dust for an explanation.

Something else worth considering in looking in on the definition of knowledge is the various different sorts of knowledge folk have noted.

The first obvious distinction is between practical and theoretical knowledge, between knowing how to do things and knowing that something is the case. Knowing that a bike has two wheels is knowing that a specified proposition is true, while it's not immediately obvious that knowing how to ride a bike is knowing something about a specific proposition. That knowing and how knowing seem to be distinct.

Some folk have supposed that "knowing how" reduces to "knowing that", that for instance what knowing how to ride a bike involves is knowing that if one pushes on a peddle the wheel will turn moving the bike forwards and that if a lean in one direction can be countered by moving one's weight in the other direction, and so forth. Ryle argued against this, that the two are indeed distinct.

A further type of knowledge that might be distinct from both of these is knowledge by acquaintance. That you can recognise your brother, that you know who they are, is perhaps different again from knowing some proposition or knowing how to do something.

Presumably, a perfect definition would give an account of these three species of knowledge.

Philosophy is, generally speaking, a lot harder than it perhaps seems. — Banno

This is an important point for me. What you write about knowledge is thought provoking and reminds me that I am an outsider to philosophy.

Presumably, a perfect definition would give an account of these three species of knowledge. — Banno

Would you say that knowledge then is similar to truth in that it is not a property which looks the same in each example? (sorry for the clumsy wording)

And it's not hard to see problems with defining knowledge as "useful information". We all know stuff that is not useful, unless one is going to specify utility in such broad terms that anything is useful—at which point being useful becomes moot. And there is useful information that is false - Newtonian physics, for example. — Banno

Indeed. I generally hold to the 'is useful for certain purposes' and while some would possibly call this a type of pragmatism, I consider it more of a lazy, 'common sense' construal of knowledge that is certainly fraught for reasons you describe.

Given these variables in our understanding of knowledge, if you had to provide a brief working description of knowledge, is there one you could contrive on the fly or a basic account you could recommend?

The following three questions probably best represent why I entered this site in the first place

How do we identify truth?
What is knowledge?
Are there moral facts?

And there is useful information that is false - Newtonian physics, for example. — Banno

Which I think is a nice example of knowledge not necessarily true. IOW I don't think our hindsight about Newton's work means that people were wrong to consider it knowledge. I think it was knowledge. (theoretical) Knowledge would be rigorously arrived at beliefs and I think we could still consider someone knowing what to do with some of Newton's laws as having practical knowledge. It'd be useful for certain jobs. They know stuff. Even if ultimately it is based on approximations and perhaps some incorrect ontological assumptions.

So what is the perfect definition of knowledge? — Cidat

There is no perfect definition of knowledge, and if you're trying to find a perfect definition you're going to be disappointed. Look at it in terms of use, how is the word knowledge or know used across a wide spectrum of subjects or contexts. In one case someone might say "I know..." to emphasize a conviction, which is simply a subjective point of view, or simply an expression of their feelings about a particular belief. In such a case the person may not have good evidence or reasons, and so their belief isn't justified. In fact, in this e.g. one could even challenge this particular use as being knowledge at all, as Wittgenstein did in his notes called On Certainty.

Another use of know that is stressed by philosophers is acquiring knowledge through correct reasoning or the use of logic (inductive and deductive reasoning), which is also used in science. Much of science is based on inductive reasoning as a result of experimentation or observation.

A third use of know refers to knowledge gained by testimonial evidence. This is used in courts of law where the testimonial evidence is challenged or accepted depending on its strength. People often forget that this kind of evidence comes in the form of lectures, books, friends and family, etc. Without testimonial evidence much of what we believe would simply collapse. Being able to evaluate good testimonial evidence is a skill, because testimonial evidence can also be very weak. However, on the other hand it can be very strong depending on the circumstances.

A fourth way of knowing is pure reason or pure logic, viz., I know based on the logical structure. An e.g. is a tautology, "Either dogs are animals or they are not animals" is a tautology. It has the form either X is true or Y is true (X or not X).

Another use is that which is known by sensory experience. For e.g., "I know the orange juice is sweet because I tasted it."

Another use of know is linguistic training, i.e., I know is based on the correct public use of words or concepts.

In many of these uses there is considerable overlap. For e.g. in science sensory experience is part of observation.

So there are a variety of uses of know depending on the language-game, as Wittgenstein would say.

Perhaps we may define knowledge as "Beliefs based on rigorously tested sensory beliefs"?

Would you say that knowledge then is similar to truth in that it is not a property which looks the same in each example? — Tom Storm

Since to know something is to know that it is true, the philosophical issues around truth carry over to knowledge.

I'll go over my views on truth again, since you asked how it relates to knowledge. First i think there are two questions that sometimes get conflated; the first is, what does "...is true" mean? The second, how do we tell if some sentence is true?

Now I think Davidson's account is as good as we have gotten so far on the meaning of truth. It's the T-sentence, that a sentence "P" is true if and only if P. so "The kettle is boiling" is true iff and only if the kettle is boiling. It seems to me that this account brings together the coherence, correspondence and redundancy of truth, ideas to which philosophers keep returning.

But of course while this tells us the meaning of truth, it does not tell us which sentences are true and which are false. And I don't think, given the wide variety of sentences we can use, that there can be any such broad account. Each of the main contenders – correspondence, coherence, pragmatism and so on – have issues and limitations. Certainly there can be no algorithm into which we can feed a sentence and get a result of "true" or "false".

And I think this algorithmic view mischaracterises what is going on here. When we move from what "...is true" means to which sentences are true, we've moved away from truth and towards belief. The question "which sentences are true?" has much the same extension as "Which sentences ought we believe?". So we are now treating with belief.

Now while truth is about sentences, belief is about what people think of sentences. This is where the distinction between what is true and what is thought to be true comes into play. Whereas truth is monadic, being about some sentence, belief is dyadic, being about both some sentence and a believer. That is, the kettle is either boiling or not is about the kettle, while that one believes the kettle is boiling is about both the believer and the kettle. This is of importance because idealism and anti-realism work by denying this distinction between truth and belief. For them something is true only if it is believed (or perceived, or whatever) to be true.

Anyway, none of this is without detractors, but that gives a bit of an indication of what I think, and yes, knowledge is not the sort of thing for which we can give a single complete account.

And that's the answer to 's post.