What do we know?

[Jon_]

It is not invalid, it just does not lead to a necessarily true conclusion.

That is the definition of invalidity.

You know, I am actually okay with this. It dovetails with my larger point that this fixation on absolute epistemological justification is a red herring, because there ain't no such animal.

Really? Then how do you justify the assertion that there is no absolute epistemological justification?

What good is it to define knowledge as something impossible in principle to obtain, then complain that we can't know anything?

Well, I never said we can't know anything. I merely argued that we cannot know anything based on empiricism.

Soli Deo Gloria

Jon

 

[Patzak]

The latter says that we believe the sun will rise based on observation. We acknowledge that this is insufficient justification to assert the conclusion is necessarily true, but the practical consequences of believing the sun rises and sets in such a fashion outweigh the skeptical rejection of the argument on the basis of its invalidity.

But we're not looking for justification for a belief that something is neccessarily true - in that case, I agree, only deduction should count as justification. But we're not speaking only of neccessary truths - believing that the sun will rise the next day is believing in a contingent truth. We can certainly envision a scenario in which the sun doesn't rise. I would call the inductive reasoning here a sufficient justification of a belief. Though we do run into the problem of how to quantify it - how many successful examples is enough to call something justified? I've no idea. So I can see the problems we run into if we justify our beliefs with inductive reasoning. However, accepting only deduction seems a little extreme; you lose the "true" criterion since anything justified is automatically true - and also not true independently but because of your justification (the possibility of justification is what makes it true). So justification and truth blend into a single criterion and the definition of knowledge becomes "a logically sound belief".

Well, the real problem, which Hume addressed, is that no one has ever sensed a "real" object. The only experience we have of the world is our perceptions, which may or may not be correct at all. No one has ever seen the sun, for instance, we have only had the perception that we were seeing the sun. Think of The Matrix; it's kind of like that.

I don't really see what you're getting at with this. I might never know the ultimate reality, I agree. But there's no reason why I couldn't know that "all fish-shaped perceptions live in a water-shaped perception". Sounds silly, of course, but it addresses the immediate reality perfectly accuratelly.

 

[TeddyKGB]

That is the definition of invalidity.

In a deductive context.

Really? Then how do you justify the assertion that there is no absolute epistemological justification?

My thought was incomplete; I meant to put "empirical" in there somewhere.

Well, I never said we can't know anything. I merely argued that we cannot know anything based on empiricism.

As did I.

 

[Jon_]

But we're not looking for justification for a belief that something is neccessarily true - in that case, I agree, only deduction should count as justification. But we're not speaking only of neccessary truths - believing that the sun will rise the next day is believing in a contingent truth.

How do you know "the sun will rise the next day" is even contigently true? What is it contingent upon? How do you know that?

We can certainly envision a scenario in which the sun doesn't rise. I would call the inductive reasoning here a sufficient justification of a belief.

You can make the claim that anything is sufficient justification for any given truth claim, but if you take an invalid form of reasoning (induction) you leave yourself wide open to criticism. Your system will ultimately result in skepticism because all of your inferences will be invalid.

Though we do run into the problem of how to quantify it - how many successful examples is enough to call something justified? I've no idea. So I can see the problems we run into if we justify our beliefs with inductive reasoning.

That's not the only problem. There is also the problem of showing how any inference from sensation is valid. There is the problem of computing not only the numerator of the probability, but the denominator. For any given open induction, the denominator is effectively infinity. Any given probability out of infinity is a mathematical impossibility, hence, your probability of picking the correct inference in an inductive procedure is zero. See Karl Popper's The Logic of Scientific Discovery.

However, accepting only deduction seems a little extreme; you lose the "true" criterion since anything justified is automatically true - and also not true independently but because of your justification (the possibility of justification is what makes it true). So justification and truth blend into a single criterion and the definition of knowledge becomes "a logically sound belief".

"A logically sound belief," is a good definition for knowledge, but I would contend that it is compatible with the Platonic definition of "justified true belief." Of course, Plato was a rationalist too (one of the reason's why Gettier's argument against the Theaetatus is a straw man), and he saw no difficulty in assigning the definition to his philosophy.

What one must consider is that something can be true without knowing it. Us knowing a given proposition does not make it true; however, we must have justified belief (a sound argument) before we can call it knowledge. For instance, the proposition that a triangle cannot have two right angles is true whether or not anyone knows it. Moreover, the equation two and two are four is true whether or not a person has learned it. So, in this sense, truth is best expressed in a realistic (that is, pertaining to realism) worldview; and knowledge comes by a system of deduction.

I don't really see what you're getting at with this. I might never know the ultimate reality, I agree. But there's no reason why I couldn't know that "all fish-shaped perceptions live in a water-shaped perception". Sounds silly, of course, but it addresses the immediate reality perfectly accuratelly.

The problem with this is that your perceptions are relative to you. Your perceptions are not my perceptions. If we settle for a Matrix-type subjectivist worldview, we end up obliterating any concept of universals. But universals indeed exist; therefore, the epistemology of solipsism fails on this count. There must be an objective system of truth, the knowledge of which follows by necessary consequence from its first principles.

Soli Deo Gloria

Jon

 

[Jon_]

In a deductive context.

I'm not sure what this means. "Deductive" is simply a descriptor for valid rules of inference, i.e. the laws of logic. If something is not deductive, then it is illogical, which means it does not follow from its premises. Induction, whether within a "deductive context" or not, is illogical—it's not true.

My thought was incomplete; I meant to put "empirical" in there somewhere. As did I.

Looks like we're close to being on the same page, then.

Soli Deo Gloria

Jon

 

[CSMR]

It depends.

If it is the case that all the factors influencing the roll can be known/predicted, then an objective probability can be assigned.

What are "all the factors". Are you thinking of factors in the context of a scientific theory? And then presumably allowing for non-deterministic scientific theories? What is a non-deterministic scientific theory except an expression of ignorance over a particular set of deterministic theories?
Einstein's comment "God does not play dice" needs to be understood.

If it is the case that at least one of the influencing factors cannot be known/predicted (a la Heisenberg)

Perhaps quantum mechanics is the problem here. Probability is a mathematical construct within the theory. It ought to have been named something else. If quantum mechanics had called probability p or some other symbol or word there would be much less misunderstanding of science in the world.

 

[Patzak]

How do you know "the sun will rise the next day" is even contigently true? What is it contingent upon? How do you know that?

I don't. I will know it when it actually does. Maybe "contingent" was a bad choice of words. What I meant was: the belief I'm trying to justify isn't that there's no possible scenario in which the sun wouldn't rise the next day; only that it will rise tomorrow. I agree, there's no way of me knowing that; but at this point, I'm not claiming to know it - just that it is a justifiable belief.

You can make the claim that anything is sufficient justification for any given truth claim, but if you take an invalid form of reasoning (induction) you leave yourself wide open to criticism. Your system will ultimately result in skepticism because all of your inferences will be invalid.


That's not the only problem. There is also the problem of showing how any inference from sensation is valid. There is the problem of computing not only the numerator of the probability, but the denominator. For any given open induction, the denominator is effectively infinity. Any given probability out of infinity is a mathematical impossibility, hence, your probability of picking the correct inference in an inductive procedure is zero. See Karl Popper's The Logic of Scientific Discovery.

Sorry, this is all going a bit over my head. So you'll have to either rephase it or wait for me to read the book (which might take some time...) .

What one must consider is that something can be true without knowing it. Us knowing a given proposition does not make it true; however, we must have justified belief (a sound argument) before we can call it knowledge. For instance, the proposition that a triangle cannot have two right angles is true whether or not anyone knows it. Moreover, the equation two and two are four is true whether or not a person has learned it. So, in this sense, truth is best expressed in a realistic (that is, pertaining to realism) worldview; and knowledge comes by a system of deduction.

I think the point of our disagreement lies in that we understand the concept of justification differently: I see it mainly as "a reasonable gronds" while you think of it as "being able to deductively prove". I'm not particularly familiar with analytical philosophy, so your use might be the correct one - I wouldn't know.

But: it still seems to me that in your view the truth of something arises from the justification itself. Of course, it might be preexistent to our knowledge as in the examples you give - but two and two are four precisely because of the mathematical axioms that deductively lead to it. It stops being an independent factor and becomes part (or result) of what you give as its justification.

The problem with this is that your perceptions are relative to you. Your perceptions are not my perceptions. If we settle for a Matrix-type subjectivist worldview, we end up obliterating any concept of universals. But universals indeed exist; therefore, the epistemology of solipsism fails on this count. There must be an objective system of truth, the knowledge of which follows by necessary consequence from its first principles.

Could you elaborate on this? I'm not espousing a solipsistic worldview - I'm just saying it's irrelevant; knowledge functions the same way regardless of whether the world is the final reality or merely a Matrix-like illusion - the difference is only between calling something a thing in itself in one case and a sensory phenomenon in the other.

 

[Jon_]

I don't. I will know it when it actually does.

That's what I was asking. How do you know "when it actually does"? By seeing it? We already covered the problems with "seeing" something as being justification for knowledge. The Gettier problem illustrates the incapability of empirical observation to confirm anything.

Maybe "contingent" was a bad choice of words. What I meant was: the belief I'm trying to justify isn't that there's no possible scenario in which the sun wouldn't rise the next day; only that it will rise tomorrow. I agree, there's no way of me knowing that; but at this point, I'm not claiming to know it - just that it is a justifiable belief.

Okay, I understand this. The only problem is that your use of "justify" here is different than the epistemological criterion of justification. In epistemology, we say that justification is that specific line of reasoning that confirms the necessary inference from belief to truth. For instance, the proposition, "A triangle cannot have two right angles" follows from the definition of triangle, which includes the propositions, "A triangle has three sides," and, "The sum of the angles in a triangle is 180 degrees" (we're talking about Euclidean geometry here, obviously).

So, I would say that your belief is plausible. This term is less often confused with the epistemological criterion of justification and is generally understood within the context. We might even say "reasonable" as long as we make sure to note before hand that by "reason" we do not mean "rational," which is a common meaning of "reason."

Sorry, this is all going a bit over my head. So you'll have to either rephase it or wait for me to read the book (which might take some time...) .

Ah, I'm sorry. Yes, let me rephrase it.

In order to calculate the probability of any given proposition, you first need to know how many other propositions are possible. When this comes to invalid propositions, there are an infinite number of possible alternative invalid propositions. For instance, we might say, "Everytime it rains, the ground gets wet. Therefore, the rain causes the ground to get wet." This seems plausible, but because the proposition follows post hoc fallacy, it is invalid. If we were to allow invalid propositions to be true, then we must allow any invalid proposition to be true. Therefore, we might say, "Everytime it rains, the ground gets wet. Therefore, the number three is yellow." This proposition is also invalid and absurd, just much more obviously so; however, it is no more invalid than the argument that rain causes the ground to get wet.

When we come to inductive arguments, we seemingly have escaped this problem. Instead of simply asserting something is true based on observation, we instead try to assign a probability to it.

Everytime I have seen it rain, I have seen the ground get progressively wetter in proportion to the amount of rain. Those parts of the ground that are not expoused to the water did not get wet. I have seen this phenomenon 100 times. I have also poured water on the ground when it was not raining and the ground got wet. I also saw this phenomenon 100 times. Based on these observations, I conclude that it is probable that water makes the ground wet. In the cases that I tested, the probability was 1:1, or 100%. What is the probability that water always makes the ground wet (given a high enough portion of water)?
​

Let's forego the problems with sensation and get straight onto the reasoning. I observed water causing the ground to get wet 200 times. So where do I go wrong when I say that water probably if not always makes the ground wet?

Well, it's simple—I haven't observed that. At best, I can only say that everytime I observed rain or water being poured on the ground, I observed the ground getting wet. This is all that can be inferred from these observations. It is completely invalid to infer from a particular to a general, even a general probability. If I flip a two sided coin 100 times and everytime it comes up heads, can I validly infer that the next flip will comes heads as well? (Note that the coin does indeed have heads and tails.) You will say, "Of course not; the probability it will come tails is always 50%"—and you would be right.

That raises the biggest problem of induction. What is the probability that water causes the ground to get wet? In order to calculate that, you would have to know every time in the past taht water caused the ground to get wet and every time in the future where water causes the ground to get wet. You would then have to also know all the instances where water did not cause the ground to get wet. There are many other considerations, maybe even an infinite number, but you can see from just this that it is impossible to assign a probability to the proposition, "Water makes the ground wet." There are an unknowable number of instances of rain making the ground wet and non-rain not making the ground wet. It is impossible to test them all, so the conclusion does not follow from the premises.

I think the point of our disagreement lies in that we understand the concept of justification differently: I see it mainly as "a reasonable gronds" while you think of it as "being able to deductively prove". I'm not particularly familiar with analytical philosophy, so your use might be the correct one - I wouldn't know.

Oh, it's not an aspect of analytic philosophy; it's a requirement of any epistemological theory because it is necessarily inferred by logic.

(Just as a side note, analytic philosophy refers to the Vienna Circle school of philosophy from which birthed Logical Positivism and all other manner of positivistic philosophical systems. Common proponents of this view are Wittgenstein, Feigl, and Carnap. Wittgenstein especially was into the philosophy of language, which is a primary consideration of analytical philosophy. Bertrand Russell and Gottleb Frege were particularly interested in this aspect of analytic philosophy (before it was even analytic philosophy), denouncing Aristotelian term logic and instituting symbolic logic (which later became predicate logic) in its place.)

But: it still seems to me that in your view the truth of something arises from the justification itself. Of course, it might be preexistent to our knowledge as in the examples you give - but two and two are four precisely because of the mathematical axioms that deductively lead to it. It stops being an independent factor and becomes part (or result) of what you give as its justification.

I see justification as the argument that concludes in the truth to be believed. The assertion itself is true. The belief itself can be independent of the justification. But we cannot rightly call it knowledge unless the proposition, i.e. the argument, or the reasoning, is present. For instance, the proposition, "A triangle cannot have two right angles" is a true assertion. I also believe this to be true. But this proposition cannot stand alone as knowledge. It is susceptible to the inquiry, "How do you know?" At that point, I must show that the definition of triangle and the axioms of Euclidean geometry necessarily conclude in the proposition. This is the justification of knowledge.

Now, you argue that the truth then becomes dependent on the justification, but this does not follow. The proposition is true whether or not we know it to be true. It is our knowing of the truth that is dependent on the justification.

I think what you might be saying is that the truth of a proposition is dependent on its axiom(s). That is, of course, completely true. But it is also true that even if we believe the axiom(s), we might not know the proposition. It must certainly be said that we cannot know the proposition without believing the axiom(s), though.

I say "believe the axiom(s)" because axioms cannot be proven. They are not propositions; they are those from which we justify propositions. An axiom cannot be confirmed, verified, or proved, it can only be believed.

Could you elaborate on this? I'm not espousing a solipsistic worldview - I'm just saying it's irrelevant; knowledge functions the same way regardless of whether the world is the final reality or merely a Matrix-like illusion - the difference is only between calling something a thing in itself in one case and a sensory phenomenon in the other.

No, I wasn't implying you are espouing a solipsistic worldview. My point is that axioms are completely essential for any kind of knowledge at all. Unless you can take your argument all the way to a self-authenticating axiom, your argument will fall apart ultimately.

When I say "self-authenticating," I mean that the axiom necessarily implies itself. A good example of a non self-authenticating axiom is the first principle of Logical Positivism: "Only propositions verifiable by sensory experience can be known." The reason this is inauthentic is because the axiom itself is not verifiable by sensory experience. It is self-contradictory.

Soli Deo Gloria

Jon

 

[Patzak]

That's what I was asking. How do you know "when it actually does"? By seeing it? We already covered the problems with "seeing" something as being justification for knowledge. The Gettier problem illustrates the incapability of empirical observation to confirm anything.

I'd say it only illustrates its incapability to confirm anything about the thing in itself. But what if I actually don't care about the thing but only about the sensation itself? So when the sun comes up the next day, I agree, I cannot confirm that it is actually the same sun that I saw yesterday or even that it's anything other than a sensory phenomenon. But I'm not interested in the "real" sun - I'm only interested in whether tomorrow morning I will perceive the sun to come up - and when this happens, I will have confirmed my belief from the previous day.

Ah, I'm sorry. Yes, let me rephrase it.

In order to calculate the probability of any given proposition, you first need to know how many other propositions are possible. When this comes to invalid propositions, there are an infinite number of possible alternative invalid propositions. For instance, we might say, "Everytime it rains, the ground gets wet. Therefore, the rain causes the ground to get wet." This seems plausible, but because the proposition follows post hoc fallacy, it is invalid. If we were to allow invalid propositions to be true, then we must allow any invalid proposition to be true. Therefore, we might say, "Everytime it rains, the ground gets wet. Therefore, the number three is yellow." This proposition is also invalid and absurd, just much more obviously so; however, it is no more invalid than the argument that rain causes the ground to get wet.

When we come to inductive arguments, we seemingly have escaped this problem. Instead of simply asserting something is true based on observation, we instead try to assign a probability to it.

Everytime I have seen it rain, I have seen the ground get progressively wetter in proportion to the amount of rain. Those parts of the ground that are not expoused to the water did not get wet. I have seen this phenomenon 100 times. I have also poured water on the ground when it was not raining and the ground got wet. I also saw this phenomenon 100 times. Based on these observations, I conclude that it is probable that water makes the ground wet. In the cases that I tested, the probability was 1:1, or 100%. What is the probability that water always makes the ground wet (given a high enough portion of water)?
​

Let's forego the problems with sensation and get straight onto the reasoning. I observed water causing the ground to get wet 200 times. So where do I go wrong when I say that water probably if not always makes the ground wet?

Well, it's simple—I haven't observed that. At best, I can only say that everytime I observed rain or water being poured on the ground, I observed the ground getting wet. This is all that can be inferred from these observations. It is completely invalid to infer from a particular to a general, even a general probability. If I flip a two sided coin 100 times and everytime it comes up heads, can I validly infer that the next flip will comes heads as well? (Note that the coin does indeed have heads and tails.) You will say, "Of course not; the probability it will come tails is always 50%"—and you would be right.

That raises the biggest problem of induction. What is the probability that water causes the ground to get wet? In order to calculate that, you would have to know every time in the past taht water caused the ground to get wet and every time in the future where water causes the ground to get wet. You would then have to also know all the instances where water did not cause the ground to get wet. There are many other considerations, maybe even an infinite number, but you can see from just this that it is impossible to assign a probability to the proposition, "Water makes the ground wet." There are an unknowable number of instances of rain making the ground wet and non-rain not making the ground wet. It is impossible to test them all, so the conclusion does not follow from the premises.

I hate to answer like this, seeing you took the time to write all that at my request after I didn't understand your first formulation, but I can't say much more than that I agree.
Just as a sidenote: what about the sciences that in fact do assign probabilities to conclusions that were arrived at by induction? That may be a subject for a different thread though.

I see justification as the argument that concludes in the truth to be believed. The assertion itself is true. The belief itself can be independent of the justification. But we cannot rightly call it knowledge unless the proposition, i.e. the argument, or the reasoning, is present. For instance, the proposition, "A triangle cannot have two right angles" is a true assertion. I also believe this to be true. But this proposition cannot stand alone as knowledge. It is susceptible to the inquiry, "How do you know?" At that point, I must show that the definition of triangle and the axioms of Euclidean geometry necessarily conclude in the proposition. This is the justification of knowledge.

But your proposition in this case is only true if the geometry we're considering is Euclidean. It's only true because you accept the fifth (I think?) Euclidean axiom. I'd say that the correct question to ask in this case isn't "How do you know?" but "Why is it true?". Or maybe both, but definitely not only the first one.

I think what you might be saying is that the truth of a proposition is dependent on its axiom(s). That is, of course, completely true. But it is also true that even if we believe the axiom(s), we might not know the proposition. It must certainly be said that we cannot know the proposition without believing the axiom(s), though.

I say "believe the axiom(s)" because axioms cannot be proven. They are not propositions; they are those from which we justify propositions. An axiom cannot be confirmed, verified, or proved, it can only be believed.

Ah. I wrote my reply to the previous paragraph before reading this one. Anyway, I guess I'll have to agree that deductive reasoning is in fact justification for a truth. You make a good point.

 

[Jon_]

I'd say it only illustrates its incapability to confirm anything about the thing in itself. But what if I actually don't care about the thing but only about the sensation itself? So when the sun comes up the next day, I agree, I cannot confirm that it is actually the same sun that I saw yesterday or even that it's anything other than a sensory phenomenon. But I'm not interested in the "real" sun - I'm only interested in whether tomorrow morning I will perceive the sun to come up - and when this happens, I will have confirmed my belief from the previous day.

The problem with this is that it affirms the consequent. "I had the sensation of the sun yesterday and every other day before that, so I infer that I will see the sun tomorrow. Now I did see the sun. Therefore, I knew the sun would rise." This argument is formally fallacious. Even if you simply argue on the basis of subjective perceptions, you still cannot make any predictions about future experiences without committing a logical error. It's not your fault. No one can do it. It's just a fact of logic.

But seeing the sun come up everyday of your life certainly lends a large measure of plausibility to the belief it will come up tomorrow. We just can't say it's true based on empirical observation. We must infer it from an established truth.

I hate to answer like this, seeing you took the time to write all that at my request after I didn't understand your first formulation, but I can't say much more than that I agree. Just as a sidenote: what about the sciences that in fact do assign probabilities to conclusions that were arrived at by induction? That may be a subject for a different thread though.

Science assigns probabilities to formulas based on assumptions that it has made concerning observations. You will see that "constants" used in science are not constant at all (here's a good article on the subject: http://physicsweb.org/articles/news/5/8/11). They are based on repeated observation. If they occur consistently, then the scientists believe they have discovered some kind of natural law that they can use to predict future experiences. But this follows the same line of reasoning above and results in a logical fallacy.

But your proposition in this case is only true if the geometry we're considering is Euclidean. It's only true because you accept the fifth (I think?) Euclidean axiom. I'd say that the correct question to ask in this case isn't "How do you know?" but "Why is it true?". Or maybe both, but definitely not only the first one.

Right. That is why I mentioned that your axioms are absolutely essential. This is why there are so many different worldviews and why most of them are in conflict. They are all based on different axioms. If there was some universal starting point from which we could begin, I believe there would be much greater agreement on what is true.

Ah. I wrote my reply to the previous paragraph before reading this one. Anyway, I guess I'll have to agree that deductive reasoning is in fact justification for a truth. You make a good point.

Okay, great. So now that we have concluded on the proper method of justification (deduction), it now falls upon us to find the proper axiom(s) to supply us with the truth that we so eagerly desire. Very few people are satisfied with a solipsistic or skeptical worldview. We want knowledge. We want to know why (if there is a purpose) we are here and what can be said truthfully about our existence.

I submit to you that the Bible and the Bible alone is able to consistently and cogently furnish this truth.

Soli Deo Gloria

Jon

 

[Morallyangelic]

Okay, after reading that I'm probably more confused than I was before I read it.

My simple mind wants to think that the only way to actually KNOW the table is there is to observe it tangibly rather than empirically.

Would I be incorrect in this thinking?

 

[PKJ]

Let's accept the OP definition of "justified true belief".

Justified true belief or 100% sure true dogma?

Knowing there's a table in the other room means that I am justified to think so. What would make me justified to think so? Because I have evidence for it. What would be appropriate evidence for it? Many things! (How about you bring a whole panel of judges in your kitchen to testify for the table existence?) Still, you might be wrong and so might be the judges. But it does not really matter, as human knowledge has absolutly no pretention to be 100% accurate all the time. Only religions pretend that such knowledge is possible.

Against solipsism

So, yes, it is possible to know such things, otherwise you'd fall into a very silly solipsism. (I'm talking to you Berkeley fans!) Why is solipsism silly? Because it makes everything rely on the "self", and assumes (out of nowhere) that you make stuff exist with your mind. But the "self"/mind is not a good basis for knowledge, it is constantly changing (cf William James). What right have I to say that the world revolves around "I" when I don't even know who that "I" is? In fact, that "I", the cartesian "I", is a disembodied concept, it means nothing really, unless it is in relation with other objects that are external to it. Which brings me to Sartre's ontological proof for the existance of external objects:

1) I am not conscious unless consious of something
2) I am conscious, so there has to be "something"
Conclusion: There are objets outside the field of my consciense.

Heidegger's modes of existence

Objets "exist" in 3 different ways. They can be there in front of you (zuhanded), there but not seen at the moment (forhanden) or they can be, well, you (dasein). Berkeley assumes that the only way an object can exist is dasein and zuhanden. But forhanden objects "exist" too, they are in your reach. You can travel to India and see that the Taj-Mahal is real: it does not become real just because you want it to. There were people (and objects) before you and there will be people after you. The fact that you percieve stuff or not is really no big deal.

 

[Jon_]

But it does not really matter, as human knowledge has absolutly no pretention to be 100% accurate all the time. Only religions pretend that such knowledge is possible.

By your own admission, the assertion that human knowledge is not absolutely 100% accurate all the time refutes your assertion that knowledge is even possible. If knowledge, that is, a proposition, does not necessarily follow from the premises, then the proposition is false, and there is no knowledge. What you are describing is belief. So, in that sense, you're right. Where justification is impossible, belief is all that matters.

So, yes, it is possible to know such things, otherwise you'd fall into a very silly solipsism.

How do you know?

Why is solipsism silly? Because it makes everything rely on the "self", and assumes (out of nowhere) that you make stuff exist with your mind.

Which raises the question, "What do you consider existence?"

But the "self"/mind is not a good basis for knowledge, it is constantly changing (cf William James). What right have I to say that the world revolves around "I" when I don't even know who that "I" is? In fact, that "I", the cartesian "I", is a disembodied concept, it means nothing really, unless it is in relation with other objects that are external to it.

This is an assertion that cannot be maintained. It is very near the logical positivists', "Only that which can be sensed can be known." This very axiom is self-contradictory, though, for it cannot be sensed. Geometry cannot be sensed. Have you ever seen a triangle? No, you haven't. You have seen triangular shapes, but a geometric triangle is not a sensible object. To deny that it exists or to say it is meaningless simply begs the question. We are concerned with what exists and with what is meaningful. Simply discarding concept a or person x as non-existent is circular.

Which brings me to Sartre's ontological proof for the existance of external objects:

1) I am not conscious unless consious of something
2) I am conscious, so there has to be "something"
Conclusion: There are objets outside the field of my consciense.

This inference is invalid. The term "outside the field of my conscience" does not appear in either of the premises. It may be the case that you are conscious of your consciousness, e.g. cogito ergo sum.

Objets "exist" in 3 different ways. They can be there in front of you (zuhanded), there but not seen at the moment (forhanden) or they can be, well, you (dasein). Berkeley assumes that the only way an object can exist is dasein and zuhanden. But forhanden objects "exist" too, they are in your reach. You can travel to India and see that the Taj-Mahal is real: it does not become real just because you want it to. There were people (and objects) before you and there will be people after you. The fact that you percieve stuff or not is really no big deal.

I think this is a misrepresentation of Berkeley's view, but I have no interest in defending him. Suffice it to say that you have a whole lot of work ahead of you before you can assert sensation fits the criteria of justification. You might want to start by showing how the inference from sensation to perception to existence is valid. I have yet to see anyone come even close.

Then again, you could simply ignore the problem, which is what 98% of people do.

Soli Deo Gloria

Jon

 

[Jon_]

Okay, after reading that I'm probably more confused than I was before I read it.

My simple mind wants to think that the only way to actually KNOW the table is there is to observe it tangibly rather than empirically.

Would I be incorrect in this thinking?

Yep.

Soli Deo Gloria

Jon

 

[Received]

In case this hasn't been stated, what satisfies as knowledge?

 

[Jon_]

In case this hasn't been stated, what satisfies as knowledge?

We're working with the traditional Platonic definition: justified true belief. Therefore, for any given proposition the following criteria must be satisfied to serve as knowledge.

1) You must believe the proposition to be true.
2) You must have justification for believing it to be true.
3) The proposition must be true.

Soli Deo Gloria

Jon

 

[CLAY1960]

The reality is that humans are connected to the Matrix.... let me free your mind... in my hands I have two pills..... the red one.......