# How do we know, that what we know, is what we REALLY know? **URL:** \ **Category:** Great Debates\ **Created:** [November 26, 2003, 2:57am UTC](https://boards.straightdope.com/t/how-do-we-know-that-what-we-know-is-what-we-really-know/215308 "2003-11-26T02:57:43Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [December 4, 2003, 11:22pm UTC](https://boards.straightdope.com/t/how-do-we-know-that-what-we-know-is-what-we-really-know/215308/41 "2003-12-04T23:22:23Z")
Yes, I am very fond of what I’ve read of phenomenology. Kant is a traditional transcendental idealist, so it is easy to see why labels can be rough. This is really true of all labels in philosophy, though. They give you an estimate of what the person thinks, but can’t flesh it out thoroughly. > [@](#): > > Anyway, however you want to label your viewpoint, I think I now understand that what you are calling “objects” are really shared inter-subjective experiences. Knowledge consists of the demonstration or communication of subjective experience. If there are “things-in-themselves,” they are not knowable as such and so it is meaningless to talk about them. That’s fairly close. If you lean towards a “things-in-themselves” interpretation of existence then it is a safer phrasing you give. I’m quite an idealist. The transcendental part only emphasises the idea that we are going beyond pure subjectivity. The conscious mind is not locked there in the manifold of sensation. > [@](#): > > My reading of the Britannica article on epistemology suggests that your position is closer to phenomenalism (especially as that view includes the “coherence” of perceptual experiences that you mentioned earlier). Sounds good. Husserl, who is right now my secondary influence, was the father of phenomenology. ---
**Author:** ![ekow2kn3](https://avatars.discourse-cdn.com/v4/letter/e/ecc23a/32.png) [@ekow2kn3](https://boards.straightdope.com/u/ekow2kn3)\ **Post date:** [December 5, 2003, 6:42am UTC](https://boards.straightdope.com/t/how-do-we-know-that-what-we-know-is-what-we-really-know/215308/42 "2003-12-05T06:42:03Z")
Basically it does not matter, what is real is what we experience, and we don’t have an option of experiencing anything different. Real is what we personally experience, so even if i am in a machine…it doesnt matter because what i am experiencing is real to me, however what is real to me might not be to someone else. If you are saying real as something that is believed by everyone, then it is impossible, because there will always be someone who thinks that gravity is a conspiracy or something like that ---
**Author:** ![MyOld85MG](https://avatars.discourse-cdn.com/v4/letter/m/439d5e/32.png) [@MyOld85MG](https://boards.straightdope.com/u/MyOld85MG)\ **Post date:** [December 5, 2003, 5:18pm UTC](https://boards.straightdope.com/t/how-do-we-know-that-what-we-know-is-what-we-really-know/215308/43 "2003-12-05T17:18:14Z")
> [@](#): > > \*Originally posted by ekow2kn3 \* > \*\*Real is what we personally experience, so even if i am in a machine…it doesnt matter because what i am experiencing is real to me, however what is real to me might not be to someone else. > If you are saying real as something that is believed by everyone, then it is impossible, because there will always be someone who thinks that gravity is a conspiracy or something like that \*\* > [@](#): > > \*Originally posted by erislover \* > \*\*If I may be so bold as to make a slur against realism, it is the metaphysic of the madman. 😉 \*\* 😃 I couldn’t help juxtaposing these quotes, because it made me think of what society calls “mental illness” (in particular, schizophrenia). Now, **if** there really is a world-out-there that operates independently of our perception of it, then it certainly makes sense to talk about the accuracy of perception. (The presumption here is that although the world operates independently of perception, perception is at least in part dependent on reality. The more dependent on reality, the more accurately we might say it represents reality.) Given that scenario, it also makes sense that some people could have faulty perceptual faculties. (The term “faulty” might not make sense if there is no independent reality.) If a person has faulty perceptual faculties, their perceptions might lead them to make serious – nay, deadly – mistakes, such as trying to fly off the top of a tall building. After which (some of us presume) their ability to perceive ceases. Further, I think most of us, whether we accept realism or not, do have an urge to continue to exist. And, whether we accept realism or not, we do expect that if we perceive what appears to be a massive truck bearing rapidly and directly onto us from two feet away, then our chances of continuing to exist are pretty small. Now, I’m sure **erislover** can demonstrate that (1) the reported perceptions of someone with schizophrenia don’t match with those of other subjects, and so are suspect without having to assume an external “reality” and (2) when a subject (i.e., the person who flies to death on the pavement below) ceases to report perceptions, we really don’t know whether they have ceased to have them. But I guess it still looks to me as though you are **acting as if** there were an external reality, a reality that you need to understand reasonably accurately in order to survive. I’m sure, in your daily lives, you are just as careful to scour your sense data for possible dangers (and opportunities) as you would be if you thought there were an external reality. The main difference I can see between **erislover** ’s position and realism is the constant reminder that whatever you “know” consists entirely of mental concepts, whether they are your interpretation of sense data or of the apparent communication acts of others regarding their alleged sense data. On the other hand, most people presume that their perceptions represent something real, and I suppose they can get too confident of their ability to undertand “reality” via their sense data. That can lead to mistakes, too. Schizophrenia and overconfidence might be equally problematic. Another difference between transcendant idealism/phenomenalism and realism is that **erislover** classifies most people (and, I suspect, also those with schizophrenia) as “madmen” ;), whereas a realist would classify **erislover** as a “madman” only if he claimed to perceive something totally inconsistent with reality. (Sorry, I just had to slip that in.) (And the key here is that **erislover** is completely consistent with reality as I perceive it. We just disagree on whether it makes any sense to presume certain things about that reality. Such as its existence-in-itself.) **ekow2kn3** ’s issue is a little different, and I’m curious what **erislover** says about inter-subjective disagreements (such as those who persistently claim the earth is flat, but who otherwise appear to be mentally stable). Still :dubious: but still 🙂 ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [December 5, 2003, 7:56pm UTC](https://boards.straightdope.com/t/how-do-we-know-that-what-we-know-is-what-we-really-know/215308/44 "2003-12-05T19:56:08Z")
> [@](#): > > Now, if there really is a world-out-there that operates independently of our perception of it, then it certainly makes sense to talk about the accuracy of perception. Hmm. Let’s call “precision” the degree of clustering, and “accuracy” the degree of seperation from true (in this case, reality). Assuming that, indeed, we are bound by sensation in understanding these things-in-themselves, how do we quantify “accuracy”? Doesn’t it presuppose a way to access the things-in-themselves? > [@](#): > > Now, I’m sure erislover can demonstrate that (1) the reported perceptions of someone with schizophrenia don’t match with those of other subjects, and so are suspect without having to assume an external “reality” and (2) when a subject (i.e., the person who flies to death on the pavement below) ceases to report perceptions, we really don’t know whether they have ceased to have them. Ah, this (that is, (2)) is a very interesting question, isn’t it? The funny thing about sensations is that they are, on one hand, inherently public. I couldn’t learn when it is appropriate to use the word “sad”, for example, if there wasn’t a typical external manifestation of it. On the other, there is the little problem of whether or not we are actually associating private sensation with the public phenomena; whether there is, in fact, private sensation, and whether it makes sense to talk about it. It is a topic of some discussion, actually. I remain on the side that insists that it is meaningless to talk about private sensation: whatever words we have must correspond to public phenomena. Checking, insisting on, or otherwise discussing the mapping of internal phenomena is misguided and circular. So in this case, a person who has behaved so cannot be said to be experiencing anything—otherwise the verb gets misused. > [@](#): > > Another difference between transcendant idealism/phenomenalism and realism is that erislover classifies most people (and, I suspect, also those with schizophrenia) as “madmen” , whereas a realist would classify erislover as a “madman” only if he claimed to perceive something totally inconsistent with reality. Now now. 😃 I just mean that realism is the metaphysic of the madman, it wasn’t meant to be biconditional. If I am to ultimately rely on the model of sensation for knowledge, then I can neither know nor discuss anything beyond it. The references fail to obtain. > [@](#): > > I’m curious what erislover says about inter-subjective disagreements (such as those who persistently claim the earth is flat, but who otherwise appear to be mentally stable). The component of empirical evidence is that it cannot be tossed aside, it must be replaced. The world is _genuinely_ different for two people who disagree as to its nature. If there can be agreement, one must replace strong evidence to the affirmative with stronger evidence to the contrary: knowledge isn’t dismissed, only replaced. However, what if we aren’t dealing with knowledge as I’ve outlined it above, but rather the very things which serve as a bedding in which knowledge is possible? Here it seems variations are perfectly permissible (after all, what rule could deny them?), to a point. If the variation was small, then there would be singificant miscommunication about events and instances. If the variation was larger, it would seem that the task of providing evidence to the contrary or listening to their evidence of the affirmative would be impossible: their notion of “logic”, “proof”, “validity”, and even “evidence” itself would be so skewed as to forbid any communication. It is cold comfort to simply say they are wrong. But what other choice is there if communication is impossible? Suppose someone even said, “The world of the schizophrenic is different from the world you and I live in.” How would you analyze the truth of this sentence? And, if you say it is necessarily metaphoric, _why_? Actually, hallucinations proper are very interesting to me, and not in a purely navel-gazing way. I suspect anyone who has ever experimented with hallucinogens has such an interest, or perhaps a fear. But essentially, without a significantly similar “coherent” base, inter-subjective disagreements aren’t even that; there’s simply no way to ensure that we agree on enough to have any knowledge in such an environment. Think in terms of natural science, even, for such disagreements are common: groups will form supporting one interpretation over another and seek to demonstrate their case, or rebut the others’. What will ultimately solve the problem of inter-subjective disagreement is the substitution of knowledge based on stronger evidence. Yet that still requires an agreement on what evidence is all about, and when it is stronger. ---
**Author:** ![MyOld85MG](https://avatars.discourse-cdn.com/v4/letter/m/439d5e/32.png) [@MyOld85MG](https://boards.straightdope.com/u/MyOld85MG)\ **Post date:** [December 9, 2003, 5:00am UTC](https://boards.straightdope.com/t/how-do-we-know-that-what-we-know-is-what-we-really-know/215308/45 "2003-12-09T05:00:21Z")
> [@](#): > > \*Originally posted by erislover \* > **The component of empirical evidence is that it cannot be tossed aside, it must be replaced. The world is _genuinely_ different for two people who disagree as to its nature. If there can be agreement, one must replace strong evidence to the affirmative with stronger evidence to the contrary: knowledge isn’t dismissed, only replaced.** 😕 Can you elaborate on this, particularly the last half? I’m having trouble understanding it. > [@](#): > > \*Originally posted by erislover \* > \*\*However, what if we aren’t dealing with knowledge as I’ve outlined it above, but rather the very things which serve as a bedding in which knowledge is possible? > \ > their notion of “logic”, “proof”, “validity”, and even “evidence” itself would be so skewed as to forbid any communication. > \ > But essentially, without a significantly similar “coherent” base, inter-subjective disagreements aren’t even that; there’s simply no way to ensure that we agree on enough to have any knowledge in such an environment. \*\* Yes, this is a pretty significant problem. I don’t have a lot of concern about it from my point of view, but I can see where you’re coming from. Except I do have a bit of concern with: > [@](#): > > \*Originally posted by erislover \* > **Actually, hallucinations proper are very interesting to me, and not in a purely navel-gazing way. I suspect anyone who has ever experimented with hallucinogens has such an interest, or perhaps _a fear_.** (emphasis mine) To me, the possibility that my perceptions might **not** be a reasonably close approximation to “reality” is pretty scary. To go back to the sense of my last post, a “reasonably close approximation” would be one that allows me to remain alive and with some hope of happiness, without depending on the intervention of others for my safety. I would like that to be true. > [@](#): > > \*Originally posted by erislover \* > **Assuming that, indeed, we are bound by sensation in understanding these things-in-themselves, how do we quantify “accuracy”? Doesn’t it presuppose a way to access the things-in-themselves?** Well, yes and no. Let’s take your own description of “reflexive stimulation”. It seems to consist of 1) I touch something and 2) I sense something. True, in your example, these two appear to be simultaneous, but I think if we got our EEG or brain scan equipment out, we would find that these things happen sequentially. So, I would argue that _your test of reflexive stimulation is empirical_ (to use another very loaded word). And my criterion of accuracy is empirical. In the simplest terms I can think of: the accuracy of my perception can be measured by how often certain actions that I take will result in essentially the same perception. I don’t have to grasp a “thing-in-itself”, I can just toss out a series of trial actions and see what perceptions result. I think that these perceptions result from interaction with “things out there”, so I am trying to develop an understanding or model that allows me to interact safely and reliably (to get results I expect) with those things most of the time. Naturally, I don’t usually do this intentionally, but I seem to be formed in such a way that I do this sort of thing automatically most of the time. I guess this differs from phenomenalism, because phenomenalism doesn’t try to explain _why_ perceptions “cohere” (exhibit regularities). If they do, you have something you can talk about, but it is useless to speculate about where they “come from”. So my talk about stuff “out there” and empirical interactions with it would seem like nonsense. Let’s try another tack here. Suppose we have a planet, B, on which reside intelligent beings, more or less like us, but unable to detect electromagnetic radiation. B-ings have no concept of color. On Planet B, there are (among others) two kinds of plants that B-ings cannot tell apart without eating them - one which is good to eat, and would be green if a human saw it - and one which makes B-ings sick if eaten, and would be red if a human saw it. So, B-ings over time have carefully cultivated known lines of the good plant, trying to keep it free of contamination from the bad one. Question #1: Do these plants have color? (I, of course, argue that they do.) Now, let’s say a B-ing notices that one of their pets (a P) growls sometimes out on the farm. After a while, this B-ing realizes that the P can tell the difference between the two plants, and is growling when it detects a bad one. But the B-ings still don’t know how the P can know. For our argument, let’s say that P’s can distinguish color, and that’s how they know. Soon, this information spreads across B and B-ings everywhere take P’s with them into the fields. Question #2: B-ings now have a means to determine _something_ about the plants, but what _is_ it? (I, of course, argue that they now have a primitive method of determining the color “red”, but it probably doesn’t matter.) After a while, another B-ing notices that some P’s also growl when they are around other objects. B-ings determine that these P’s growl in such a way whenever they are presented with certain objects, and that the same object always elicits growling. They wonder if there is a similarity between those objects and the bad plants. Eventually, B-ings develop a concept of “growliness” that turns out to be useful when applied to several kinds of objects other than plants (e.g., growly soil is of a type that is useful for growing good plants; growly metal is getting weak and needs to be replaced) and allows them to make judgments from a distance that used to require direct contact. Question #3: Does this not illustrate how properties of objects can exist unperceived, then be discovered and utilized? (I, of course, argue that it does.) > [@](#): > > \*Originally posted by erislover \* > **The world is _genuinely_ different for two people who disagree as to its nature.** That one sentence may capture what **I** consider the crux of the matter. The world is what it is, even though we cannot know it fully. Two people can disagree about their **interpretation** of its nature. The world will **feel** different in some ways to them. The world goes on being itself, and we go on getting whiffs of it via our senses. If we interpret the world in ways that are seriously incorrect, we will find out (e.g., when I whack my nose on that nice clean glass door). Conversely, if we don’t get noticeable feedback, the differences probably aren’t very important. Irony: I think the differences between my viewpoint and yours are pretty unimportant, other than as an intellectual exercise. That’s why neither of us has gotten a “bloody nose” from following them. Question #4: If you continue living with your viewpoint, and I, from mine, will either of us experience any negative effects due to our viewpoint? (In contrast with the flat-earthers: As a round-earther, I can set sail from California, head generally west, and have a great adventure before landing in Virginia, without having fallen off the edge. A flat-earther probably wouldn’t try that. What a loss for them!) [Previous page](https://boards.straightdope.com/t/how-do-we-know-that-what-we-know-is-what-we-really-know/215308.md?page=2)