Talk:Popper's three worlds

Robinson Crusoe

This is not directly related to the article, but indirectly related because it is about a point made in the main secondary source for this article, Heller's book. Heller wrote "Robinson Crusoe on an uninhabited island cannot have objective knowledge." But this is based on an analogy used by Popper in 1945 in The Open Society and its Enemies to explain the importance of critical analysis in objective knowledge. It is an anachronism, because Popper used the concept of three worlds much later in 1967. It is not obvious that Popper would have used this analogy to define the third world. He might have said that the quality of the third world of Robinson Crusoe is very low, because the scientific method used missed the social aspect, but without saying that there is no third world for Robinson Crusoe. I mean, if we insist to equate third world with objective knowledge, we must still consider the possibility that Popper has reconsidered the definition of objective knowledge between 1945 and 1967. Popper himself often said that he was not a fanatic of definitions. One must always consider the meaning of a word in its context. It's related to the article, because it says to me that it is useful to consider many sources to be certain not to base the article only on a specific thesis. Dominic Mayers (talk) 16:54, 30 November 2020 (UTC)

Just to add that the absence of a third world for Robinson Crusoe contradicts one of the main criteria used by Popper to argue for the independent existence of the third world. Popper considers a thought experiment in which all the technology is destroyed, but not the representation of the third world. He compares it to the situation where the representation of the third world is also destroyed. He says that we can infer the independent existence of the third world because the technology will be rebuilt much faster with the help of the third world representation. This thought experiment applies in the same way to Robinson Crusoe alone on his island. Dominic Mayers (talk) 01:01, 1 December 2020 (UTC)

Recent edits of 92.22.53.131

The recent edits of 92.22.53.131 are not vandalism, but I see two important problems with these modifications. First, the claims are not sourced and they are controversial enough to require sources. Second, the text added does not integrate well with the existing text and the result is a badly organized article with useless repetitions. The original organization was good and the modifications should have tried to respect it. There is also a third problem: The very short descriptions of the three worlds were not incorrect. They were useful and should not have been removed. A lot of work is needed to correct these problems. It's not vandalism, it's clear, because the added introduction seems very useful, though it needs to be sourced (and modified if needed so that it matches better with the sources). Dominic Mayers (talk) 14:39, 17 August 2021 (UTC)

OR

This article has become bloated and looks to be 99% WP:OR William M. Connolley (talk) 16:11, 6 December 2022 (UTC)

Because there is almost no sources and no attributions, it might feel as if it is OR, but we cannot reject the possibility that the editor (an IP) understanding and thus the content reflects a view point in sources. It's not as if it is some weird idea that cannot possibly exists in sources. I did not have the courage to read it through the entire article, but when I read the RI, I don't see that there is a thesis there that cannot be found in sources. Perhaps you mean that much of the content in the article is the understanding of the IP that has written it. Yes, but it can at the same time be a view point found in sources. The only problem that I am certain of is that there is a lack of sources and attributions. If it is what you mean by "OR", then I agree. I also agree that it is a serious issue. I almost feel that, despite that a lot of expertise might have been deployed in writing this article, it might be better to start from scratch to write a shorter and well sourced article. Dominic Mayers (talk) 18:12, 6 December 2022 (UTC)

Yes, I meant unsourced. I too haven't actually read through it all, and I too am reluctant to simply remove a pile of potentially valuable material William M. Connolley (talk) 19:49, 6 December 2022 (UTC)

This is exactly how I feel. It's too bad that people don't take the extra time needed to provide the sources for the content that they include. It is a lot more work, because even if you know that you have read the material in sources, you might not remember in which book or article. Yet, it is worth it, because WP is a collective work. Perhaps each editor individually is much less efficient, because it takes a lot of time to find the sources, but the collective work becomes much more efficient and eliable when the exact sources (with the page or the chapter in the case of a book) are provided. This article is not that useful, because it might be easier to start from scratch. Dominic Mayers (talk) 20:59, 6 December 2022 (UTC)

I've just been pointed here from the Teahouse, where I went to ask how to proceed on seeing this painfully lengthy and unsourced article. I have left a message on the most recent IP editor's Talk page asking if they can provide sources, and asking them not to add more unsourced material. My current inclination is to revert to this version from two years ago, as at least it's clearer what sources back up the information given. Tacyarg (talk) 20:02, 7 December 2022 (UTC)

Would it be a good idea to first put the article under protection so that no ip can edit it? This might attract the attention of the ip, which might not even be aware that we try to communicate with him. Dominic Mayers (talk) 20:27, 7 December 2022 (UTC)

Good suggestion, I have requested PP. Tacyarg (talk) 14:58, 4 January 2023 (UTC)

And have added a template message to the most recent IP editor's Talk page. Tacyarg (talk) 15:08, 4 January 2023 (UTC)

I'm in favor of gutting it down to a simple summary with a few inline sources. OhNoitsJamie ^Talk 19:27, 4 January 2023 (UTC)

Anything that is neutral and verifiable would be fine with me. Dominic Mayers (talk) 20:39, 4 January 2023 (UTC)

Hi to Dominic and anyone else following on this talk page.

To the best of my knowledge, I am the person responsible for most of the content in the greatly 'expanded' version of "Popper's three worlds" before it was reverted a few weeks ago (some of my contributions remain in the reverted entry in the "Worlds 1, 2 and 3" section, despite absence of referenced sources).

Until today I did not realise this entry had its own talk page all along, and only then realised this may have been a better forum for points I wished to raise regarding the recent reversion.

Perhaps predictably, I spent considerable time on this entry over the past year or more - and have, admittedly, something of a vested interest in my efforts. I also readily admit it would be unreasonable to expect everyone to have anything like the same level of interest in Popper's ideas and the accurate statement of them (my impression is that 'OhNoItsJamie' doesn't have a great interest); and it is unlikely that everyone will have an equally firm basis from which to judge what is likely accurate (and what is not) in the material presented - especially as a firm basis might mean having to carefully read and digest all the various works used in developing the 'expanded' entry.

These works include Popper's contributions to "The Self And Its Brain" (in Parts I & III), to his 'Schilpp' Volumes in 'The Library of Living Philosophers' (2 Volumes) [this is where Popper's "theorem" "World 3 > World 3.2 + World 3.1" is stated and explained], his "Objective Knowledge", and then material in various published lectures and in his "Postscript" (3 volumes), especially "The Open Universe".

I also admit that what may stick out to others - especially those who have not read all (or any) of the works listed above - is how the 'expanded' entry contains a lot of material without referenced sources provided in support. The "unsourced" objection certainly raises a real issue with the expanded entry - where it is unsatisfactory as it stands. The "unsourced" issue may also contribute to an impression the expanded article is "bloated" and contains "original research" and/or "personal analysis". However, my own view is along the lines of the two contributors above who, after discussion, seem to agree the problem with the expanded/"bloated" entry is essentially that is largely "unsourced".

Nevertheless, a question raised here for discussion is whether this admitted problem or issue justifies such an extensive reversion to the entry as it now stands - especially in its last four sections.

For as well as the issue of referenced sources there is the fundamental question of accuracy and of fairness in editorial intervention. My questioning of the revert is because it effectively replaces accurate material with inaccurate, and replaces source-based material with material that is not sourced or source-based. This seems to me a very questionable result. I am unsure it is a result demanded by correct application of Wikipedia policies and strictures.

As I understand it, an article entirely lacking referenced sources may comply with Wikipedia's strictures because the test is not whether a source has been provided but whether there is a "reasonable expectation" that a suitable source could be provided.

So, in the context of the recent "revert", the issue may become whether the reverted article complies better than the expanded entry in terms of Wikipedia's 'strictures' - using the key tests of (a) accuracy and (b) whether there is a reasonable expectation that a proper source could be given for what is stated.

In the light of the points and analysis posted on my IP talk page in three recent posts, and the content of the expanded entry itself and it having been read by one of Popper's former research assistants, my suggestion for discussion is that the expanded entry is more "Wikipedia compliant" than the reverted entry because

(a) it is more accurate (I would argue significantly more accurate, and more comprehensive), and

(b) there is a greater "reasonable expectation" that sources could be provided for the material presented.

My next point may be a delicate one but may be too important to be avoided - views on (a) and (b) might greatly vary depending on how extensively acquainted a person is with Popper's writings. For example, a person who has only a passing acquaintance with Popper's writings may be in no real position to form a "reasonable expectation", one way or another, as to whether a source could be provided for a given statement in respect of Popper's theory. Accurate editorial judgment should perhaps defer to those who know Popper's writings best - and the lack of stated objection from Popper's former research assistant, who read over the entry as it stood last December (extremely close to how it was before the revert in January), should perhaps give pause to anyone who hasn't read the works listed above.

I would of course be grateful if anyone wishing to contribute to a discussion of this would read those three posts on my IP talk page (despite their typos and sundry other errors, and despite their level of detail). But, for those who have not the time or who might want some idea of whether reading those posts might be worth their time, the gist of the main points is summarised directly below.

By way of preliminary, my three recent posts were sent by replying to my IP talk page (in response to the revert) because I thought, perhaps wrongly, this was the correct way to reply - being also unaware that this talk page existed. These posts on my IP page (the same as the one for this post) were by pressing "reply" to 'Tacyarg' and 'OhNoItsJamie' in respect of their messages - which expressed a preference for using talk pages. I understood them to be administrators. To date neither has replied on that talk page - to my knowledge they have not replied to any of the points raised with them by way of reply, beyond having referred me to Wikipedia policies and strictures.

These three recent posts contained a range of points that centre on the following:-

(1) that the expanded (or "bloated") entry is nevertheless accurate and closely based on sources (and had been read in December 2022, without any serious objection in terms of its content, by a former research assistant of Popper's who is also a published and renowned expert on Popper's work);

(2) the reverted entry contains a large number of inaccurate and/or misleading statements in its last four sections:- to be more exact, the lengthiest of my three recent posts (on my IP "talk" page, as mentioned) went through half the sentences in the last four sections of the reverted article with careful explanation of why these sentences are inaccurate and/or misleading, and pointing out that in each case these claims are not properly sourced (no sources in 6 of the 7 examples, and an irrelevant source cited in the other case);

(3) the 'expanded' entry preserved the accurate claims and footnotes that are contained in the last four sections of the reverted entry;

(4) the 'expanded' entry added a referenced and sourced explanation from Popper - "I am not offering what is sometimes called an ontology" (p.4 "The Self And Its Brain) - for why the reverted article is inaccurate/misleading in describing a World 3 entity as a "meta-object" or "form of being"; and why the reverted entry is therefore offering material that is quite contrary to Popper's stated position - with the consequence that the revert here replaces accurate, properly sourced and referenced material with inaccurate and unsourced material;

(5) as an indication of how the 'expanded' entry adhered closely to sources and how the reverted entry is unsourced and inaccurate:- the lengthiest post quoted and sourced material from Popper's work that shows the reverted entry is clearly wrong to say/imply that Popper rejects Cartesian dualism because "Popperian cosmology rejects [Cartesian] essentialism". This is because, referring to "The Self And Its Brain" pp.181-2, Popper's crucial objection to Cartesian dualism is "only" (Popper's emphasis) that it is impossible to see how an immaterial mind/spirit could materially 'push' anything i.e. the problem with Cartesian dualism, in Popper's view, is not its "essentialism" regarding an essential difference between mind and body (after all, Popper argues for mind-body interaction despite also arguing a categorical World 1 and World 2 distinction) but because of Descartes' resulting theory of causation.

For some the level of detail used in the expanded entry, and involved in defending it, may be off-putting. My own view is different. There is a level of detail that is unavoidable in reaching an accurate understanding of a theory like Popper's "three worlds", and of the cluster of related ideas and arguments that he builds around it.

For example, to suggest that Popper rejects Cartesian dualism because "Popperian cosmology rejects [Cartesian] essentialism" is crucially and deeply inaccurate and misleading because

(1) it is nothing specific to any "cosmology" that explains Popper's opposition to Cartesian dualism;

(2) it is not Popper's opposition to "essentialism" that explains it, because even if Cartesian dualism were stripped of its "essentialism" it would still lack a convincing explanation for how an immaterial entity could 'push' a material one, when 'push' is, for Descartes, only a material form of contact;

(3) Popper regards "essentialism" as at its most plausible as a theory of mind, and as having a kernel of truth in this context, saying, for example, that he believes in "something that may be called the quasi-essential (or quasi-substantial) nature of the self" - "The Self And Its Brain", p.105 fn.2.

So it is not a trivial matter (to those who want accuracy rather than shortform inaccuracy) that Popper's actual opposition to Cartesian dualism is explained, as Popper explains it at pp.181-2, because there is a clash between Descartes' view of mind as 'immaterial' and Descartes' view that this 'immaterial' mind acts causally by material 'push'. (If I were here permitted a little "personal analysis", I think Popper would regard the expression "Popperian cosmology" in this context as not just misconceived and misleading but as quite pretentious - indeed it is to avoid such pretentious but empty talk that Popper goes out of his way, at the outset of "The Self And Its Brain", to make clear he is "not offering an "ontology"", so that the revert's reference to "meta-object" and "form of being" are also crucially and deeply misleading given Popper's actual stated views and approach).

As the expanded entry sought to more comprehensively convey, though Popper may disagree with much of Cartesianism (e.g. Cartesian views of causality, of ultimate "essentialist" explanation, of the divide between humans and animals), in terms of Cartesian dualism it is really "only" Descartes' theory of causation that is a fundamental stumbling-block - according to Popper's own quoted words. And this makes sense because Popper's position could be described as broadly Cartesian in that Popper's categorical distinction between World 1 and World 2, and his description of himself as a dualist, accepts that Descartes is right in claiming a fundamental dualism of mind and body. As to sources for this Cartesian strain in Popper's thought, the best source is probably Popper himself:- e.g. (1) there is a published discussion with other philosophers where Popper suggests that discussion of mind and body (always eventually) takes us "back to Cartesianism" (i.e. to the validity of a fundamental mind-body distinction) [I am writing from memory and cannot here cite the exact source]; and (2) (perhaps a clearer example in terms of source material), Popper's discussion of Ryle's anti-Cartesian "The Ghost in the Machine" in section 30 of that title in "The Self And Its Brain". In section 30, Popper endorses the "simile" of mind as pilot of the ship, and then makes clear he agrees with the "simile...so much so that I can say of myself "I believe in the ghost in the machine."[p.105]." This clear and forthright statement shows how closely Popper explicitly allies himself with Descartes against Ryle's explicit "ghost-in-the-machine" attack on Cartesianism.

What this example also shows, I think, is that Popper's position need careful, expanded development to do it justice - and to locate his position fairly and accurately in relation to other thinkers and lines of thought. It is not a fair or accurate depiction to claim Popper opposes Cartesian dualism using merely broad brush terms like "essentialism" or by setting up a so-called "Popperian cosmology": Popper uses carefully detailed rational considerations that involve careful separation of distinct issues, as would be expected from a significant philosopher. In my view, the reverted entry remains highly inaccurate and misleading in claiming that Popper rejects Cartesian dualism because so-called "Popperian cosmology rejects [Cartesian] essentialism". I don't think this is an acceptable level of inaccuracy, especially given Popper's own clear words, as quoted. For those interested, 6 other such examples are set out in the lengthiest of the posts on my IP talk page.

So I hope this post indicates why I find the revert highly questionable - because it has the consequence that accurate material is replaced by inaccurate, and that carefully source-based material is replaced by material that is not source-based.

I also hope it helps explain why the entry gradually expanded over the last year - because short-form statements without elaboration cannot give an accurate understanding of Popper's actual "theory" and his careful thinking.

Kind regards,

DM 88.110.55.20 (talk) 01:16, 22 January 2023 (UTC)

Though it's not a requirement, it is appreciated when a user that contributes significantly creates an account. I would appreciate that. You can still remain anonymous. I would not display here what I read about Popper's philosophy, from Popper and others, because what matters is how others can verify what I wrote in sources and they don't need to know the details of what I have read to appreciate that. Regarding your statement Nevertheless, a question raised here for discussion is whether this admitted problem or issue justifies such an extensive reversion to the entry as it now stands - especially in its last four sections., my view is that, if we focalize on the final result that is expected, it does not really matter, because, either way, the amount of work required to achieve the goal is the same. If we focalize on the process, I find something useful in only having at every step only sourced contents. I haven't read the remainder of your post, but one thing you should know is that, for collaboration in wikipedia, at the least with me, it is best to only make a single point at a time, starting with the most important ones, because usually the replies received for each point that one makes have an impact on subsequent points. Dominic Mayers (talk) 01:59, 22 January 2023 (UTC)

DM, I noticed that amongst your many points you pointed to an unsourced sentence and this caught my attention. I added a reference. Of course, it does not mean that all the problems have been addressed, but focusing on the article and sources, making one point at a time, we can progress more efficiently. I am not suggesting that every point has to focalize on a detail. We can consider global issues, but one at a time in a brief manner. The common goal should be to have a well sourced article. Dominic Mayers (talk) 04:04, 22 January 2023 (UTC)

Thanks for this response and for adding a footnote. I also agree with your "one at a time" suggestion (though maybe sometimes this might be stretched to 'one or two at a time'). Certainly, the validity of content typically breaks down into a point-by-point analysis. But, in my view, adding sources will not likely solve the problems raised as to how half the sentences in the last four sections of the reverted entry are inaccurate and/or misleading. Best, DM. 88.110.55.20 (talk) 10:29, 22 January 2023 (UTC)

Dominic, reading previous material on the talk page I noticed you wrote as follows:-

Eccless, who is cited by Popper himself as a valid source on the subject, wrote:

In their material composition of paper and ink, books are in World 1, but the codified knowledge conveyed in the print is in World 3. [Bold added].

You then reference the book source, "Facing Reality", but not the page number (this is not a criticism btw).

This quotation supports the accuracy of relevant material in the expanded entry, which treats this point as crucial to correct understanding of Popper's theory, and develops from this crucial point a range of other points - the crucial point being that World 3 content does not ever 'become part of' World 1 or become 'converted' into World 1 content but always retains its World 3 character.

In the expanded entry, this crucial point is taken as supported by Popper's quoted "theorem" - "World 3 > World 3.2 + World 3.1" - and by various other points Popper makes about the character of World 3 content (e.g. about a Beethoven symphony as World 3 object not being identical with its "World 3.1" expression as a written score or physical performance, and that these "World 3.1" expressions of the symphony are themselves 'hybrid' objects of World 1 and World 3 content).

Equally this quotation from Eccles supports the relevant points made on "my" IP talk page, especially in the longest post there, which explains how statements in the reverted entry remain inaccurate and/or misleading on this crucial point - and so the reverted entry remains inaccurate and/or misleading on a point that is absolutely central to correct understanding of Popper's theory.

Moving on to the issue of "sources", and taking this point in one-at-a-time fashion in line with your suggested approach, I also suggest that there is no reliable or proper source or reference that could here be given to substantiate the reverted entry in relation to this crucial point - and that there can be no "reasonable expectation" that it could be properly sourced in this respect.

By contrast, the Eccles' quotation you cited does make "reasonable" the expectation that the contrasting, carefully developed material in the expanded entry could be "sourced" and does support the view that it is source-based.

This is one example of what I meant by saying that I don't think adding "sources" can or will remedy serious specified defects in the content of the reverted entry - in 7 out of 14 of the sentences in its last four sections.

DM 88.110.55.20 (talk) 11:56, 22 January 2023 (UTC)

I agree that the view of world 3 that you describe above can be sourced and moreover is most likely consensual to some extent in the literature―there is rarely full agreement between distinct philosophers. If there is a passage in the current version (after the revert) that contradicts this view and is not sourced, please boldly replace it by something that is sourced and provide the sources with footnotes (say using the {{sfn}} model), ideally with the relevant section. From what I understand, this view hold even without the theorem "World 3 > World 3.2 + World 3.1" , which I am not yet familiar with (I might have read it quickly in the past, but did not focalize on it) and is perhaps a restatement of other arguments. BTW, I would have discussed the passage in question and see whether it was only a bad formulation and something else what meant, but I am not sure what passage you refer to. Dominic Mayers (talk) 15:47, 22 January 2023 (UTC)

The points are set out in the response to the revert I made on my talk page - with these points part of an overall demonstration that the reverted entry contains inaccurate or misleading material that has no proper source.

These points include referring to the following words in the reverted entry:- "But, this representation of an object of world 3 into an object of world 1...." (emphasis added). The criticism of this is that it is not absolutely clear what this is meant to mean (there is no source given for it; and Popper does not speak of the "representation of an object of World 3" in this way); and, second, that the language of "into an object of world 1" is strongly suggestive of the view that the World 3 content 'becomes part of' or is 'converted into' or 'enters into' some form of World 1 content - and this absolutely is not Popper's theory but a misunderstanding of it.

For anyone interested in understanding why I argue the revert is questionable the material is set out at the IP talk page - perhaps I should copy it over to this talk page.

DM 88.110.55.20 (talk) 18:53, 22 January 2023 (UTC)

I modified the text "slightly" (but maybe in an important manner for you), added a reference and a footnote. Let me know if this solves this specific concern. There are certainly many other things to be improved and much more to say on the subject. This short version is definitively only a first outline. Dominic Mayers (talk) 00:02, 23 January 2023 (UTC)

Unfortunately, this slight modification does not solve the problem - for reasons explained at some length back in 2023.

These reasons constituted the most recent and most relevant material on the talk page until this post today, 2nd July 2026. Yet instead of being answered or acted upon (e.g. by the main article being corrected or altered in the light of these detailed and carefully sourced reasons) these reasoned criticisms have been removed from the talk page and shelved into an archive - and not merely into an archive but into a subfolder of that archive that only becomes visible by clicking on it.

In other words, directly relevant and carefully reasoned criticisms of the current entry (specifically its last section) have been made to disappear from view on this talk page while, at the same time, the person who shelved these criticisms into an archive subfolder has left on the talk page much less recent and much less relevant material - beginning with Dominic's 'Robinson Crusoe' post, above, that Dominic admits in his post is not of direct relevance to the article.

It is almost as if old and irrelevant material remains welcome on this talk page but critical material of direct relevance to the current entry is not welcome and is to be ignored - ignored both by making no adequate changes to the entry to meet the criticisms made and by then suppressing the criticisms from view on this talk page by shelving them into an archive subfolder. Certainly, if this is the response to rational criticism here it does not bode well and must be a clear deterrent to anyone who thinks that by carefully sourced rational criticism they might contribute to an improvement to Wikipedia.

From the subfolder here is a short summary of criticisms made over three years ago that still remain directly relevant to the entry as it currently stands today, 2nd July 2026:-

[this excerpt, from what after editorial interference has become designated as a "general discussion comment" in an archive subfolder, is marked below by double-asterisks]

• • The entry was expanded over 2022 partly to avoid confusions and misunderstandings such as the one in the claim "that world 1 obeys physical laws which are objects of world 3". But the revert has ensured that a confused, misleading, inaccurate and very limited understanding of Popper's theory is now back in full swing. A short list of such confusions is now given, with a short explanation of the confusion given in parentheses after each claim taken from the main entry as it stands 23rd May 2023:

(1) "The world 3 objects are embodied in world 1"

(no - only some are ever "embodied", and never "embodied" by entering into or being "in" World 1, but instead by having an "embodied" World 1 vehicle - however, it is only the World 1 vehicle that is strictly speaking "embodied" and not the World 3 content conveyed by it, and the World 3 content is only conveyed by that vehicle for as long as that vehicle lasts or exists as its vehicle within World 1).

(2) "...the intrinsic value of Hamlet as a world 3 object is embodied many times in world 1"

(no - Hamlet as a World 3 object should not be confused with its "intrinsic value" or with any form of "intrinsic value", and, more generally, its content should not be confused with its "value" [in Popper's philosophy, questions of content and of value are kept crucially distinct, and Popper does not subscribe to any theory of "intrinsic value"]; and while Hamlet may be "embodied" many times in the form of an edition of the play or a performance, its World 3 content is not embodied "in world 1" but instead is conveyed by way of World 1 vehicles).

(3) "this representation of an object of world 3 in world 1"

(no - World 1 only provides vehicles for conveying World 3 content or objects, but those World 3 contents and objects are not ever "in world 1" - for this very reason, Popper uses the terminology of "World 3.1" objects to denote, for example, a book or artistic performance where World 1 states and processes may be used to convey World 3 content, but without that World 3 content 'becoming part of' or 'entering into' World 1).

[The points at (1), (2) and (3) are addressed in more depth below on these talk pages, in reply to Dominic Mayers, where I explain that it is only in a very stretched and loose sense that we can say that World 3 content is "embodied in" World 1 objects, or states or processes. A key aspect of Popper's theory is that World 3 content always retains its World 3 character, and that World 3 content is never converted into World 1 or World 2 content (in Popper's theory, each "World" may provide vehicles for content belonging to another of the "Worlds", but, crucially, without that content becoming changed or converted into the "World" of its vehicle). Its World 3 character is as a form of permanently abstract content. That permanently abstract World 3 content may be conveyed, sometimes, by way of World 1 vehicles - but it never as such becomes "embodied" or becomes, in a literal sense, "embodied in" its World 1 vehicle. An example might be the proposition "Snow is white": its World 3 content is not literally "embodied in" the World 1 symbolism used to convey it but may remain invariant even if we alter the World 1 symbolism in some way, say by increasing the font size or by changing to another language e.g. "Schnee ist weiss".

This point is of fundamental importance to correct understanding of Popper's theory (and is no mere "straw man" or exercise in pedantry, contrary to what is suggested elsewhere on this talk page):- this point is crucial, for example, to Popper's account of how we engage with World 3 content. In Popper's account, it is not the sensory or cognitive systems that detect World 1 phenomena that give access to World 3 content (though such systems may provide a necessary underlay to accessing World 3 content, they are not sufficient for accessing it). Instead World 3 content is a kind of abstract content that can only be accessed by a sufficiently developed World 2 mind - one attuned to detecting and handling such content, especially by way of language (including both natural and mathematical language). That is why, Popper argues, only humans can access World 3 content. World 3 content is 'invisible' to, or undetectable by, other animals - even though many such animals have an elaborate and highly developed sensory and cognitive apparatus for detecting and 'handling' and 'navigating' World 1 objects, states and processes.]

(4) "Popperian cosmology rejects this essentialism"

(no and no: yes Popper rejects "essentialism" but, no, he does not primarily do so on cosmological grounds or do so by offering a "Popperian cosmology"; and no again - his rejection of Cartesian dualism is not based on its essentialism (regarding mind and matter) but on its untenable theory that an immaterial mind can effect material push on brain matter).

(5) World 3 "corresponds to the current state of our knowledge and culture"

(no, not in any precise way - in fact, only some of World 3 is part of current knowledge or culture:

(a) by making clear he accepts there is a World 3 beyond those World 3 contents grasped by human minds or "embodied" by way of World 1 vehicles - a World 3.3, as might be called, that is not part of current knowledge or culture in any meaningful sense - Popper makes clear he does not identify World 3 with "the current state of our knowledge and culture" - rather his "World 3" transcends, or is greater than, whatever may be prevalent or current in terms of knowledge or culture;

moreover, (b), there may be undiscovered artefacts that are not part of "the current state of our knowledge and culture" - as the Rosetta Stone once was - that are nevertheless vehicles for discoverable World 3 content, and where their World 3 content exists in World 3 though it is not part of "the current state of our knowledge and culture"; equally, there may be artefacts that have been forgotten, discarded or overlooked in terms of "the current state of our knowledge and culture" but where their World 3 content continues to exist in World 3).

These confusions were cleared up by the much more comprehensive and accurate account of "Popper's three worlds" that was given by the expanded entry before it was reverted (see archived history, with the expanded entry at 5th January 2023).**

For anyone interested in further discussion of these points, the material remains in the subfolder and becomes visible when you click to view. The 'expanded entry' of 5th January 2023 is also still available to be looked at and can be found by combing the entry's history. In my view, both the material in the subfolder and in the 'expanded entry' [i.e. the entry as it stood just before the massive reversion in January 2023] provide a wealth of material that gives a very different view and overview of "Popper's three worlds" to that contained in the current version of the entry.

It is important to draw attention to that fact that the 'expanded entry' of January 2023 does not contain the many false and misleading claims that have been added to the entry over the course of 2025 and which remain, uncorrected, in the current entry today. These include entirely false suggestions that Popper was an instrumentalist as regards theories (i.e. that he viewed theories as, at most, useful instruments in dealing with reality) and that Popper considered that "truth" could not, and did not, play any role in the evaluation of theories.

The current entry is also deeply misleading in treating "Popper's three worlds", especially Popper's theory of "World 3", as if it were a mere add-on to his philosophy of science and was designed or developed by Popper to shore up his non-inductivist philosophy of science.

The facts are very different. Two brief sets of points:-

(1) "Popper's three worlds" could be correct and valid as metaphysics even if (a) Popper were mistaken about induction or (b) induction were valid and essential to scientific reasoning. Conversely, "Popper's three worlds" could be incorrect and invalid as metaphysics even if (a) Popper were correct about induction or (b) induction is not valid and plays no essential role in scientific reasoning. That is, there is no general connection between the validity of "Popper's three worlds" and the validity of Popper's philosophy of science - and it is therefore wrong-headed and misleading to treat "Popper's three worlds" as if it were an add-on developed to help validate his non-inductivist philosophy of science. The current entry produces no reliable source that substantiates there being such a general connection. It offers no argument or analysis that would substantiate how the validity of one is inextricably linked with the validity of the other.

Through its narrow contextualization of "Popper's three worlds" in terms of Popper's philosophy of science, the current version of the entry misleads as to the character of "Popper's three worlds" and the breadth of its range of applications. It also misleads as to links between "Popper's three worlds" and Popper's philosophy of science. Contrary to this narrow contextualization, Popper has made clear that he drew a fundamental distinction between "objective" and "subjective" circa "1920" in the context of distinguishing "Two Kinds of Music". This objective/subjective distinction "later greatly influenced my ways of thinking in philosophy, and..ultimately led even to my distinction between world 2 and world 3" [Schilpp Vol.I, p.47]. In Popper's own account then, this crucial objective/subjective distinction not only predated his 1920s work examining the 'psychology of discovery', which in turn predated his switch by the 1930s to examining the 'logic of discovery', but the distinction played a key role in these later developments. So that far from "World 3" being a mere add-on to Popper's philosophy of science, the opposite is closer to the truth:- Popper's approach to (and philosophy of) science always had a strongly "objectivist" character, and this can be traced back to his having already drawn a key distinction between "objective" and "subjective", which later was developed into a "World 3" and "World 2" distinction within his theory of the three worlds. Accordingly, Popper's 'The Logic of Scientific Discovery' takes as central the objective 'logical forms' of scientific statements and their objective logical relations, and it nowhere admits a purely subjective psychological element as essential to their validity - their validity is to be decided in the light of 'objective' testing and 'objectively' valid deduction. It is Popper's earlier "objectivism" that here underpins his repudiation of induction - as opposed to the contrary impression given by the current entry, that Popper's view of induction underpinned the emergence of his later "objectivism". (Here we may bear in mind that induction is nearly always defended in "subjectivist" terms, for example by way of what constitutes "justified belief" or by way of subjectivist theories of probability.)

(2) The applications of "Popper's three worlds" extend far beyond scientific theorising to many other issues. Many of these were mentioned or discussed in the 'expanded entry' but are barely touched upon in the current entry. They include the following major issues:-

(i) the differences between human and machine learning;

(ii) the differences between human and animal knowledge;

(iii) the acquisition and development of human language (both at an individual level and at the level of humans as a species);

(iv) the mind-body problem [see e.g. Popper's contributions to "The Self And Its Brain"];

(v) the development of art and technology (as opposed to science);

(vi) the character and role of rationality, or critical evaluation, in the evolution of human knowledge;

(vii) the character and role of 'beliefs' and 'traditions' in the evolution of human knowledge;

(viii) how humans can have intellectual and personal freedom in a universe that is replete with myriad causal connections but where, crucially, many of those connections are not deterministic; how, for example, 'World 3' content can have a causal affect on 'World 2' mental processes, and vice versa, without these causal interactions having a deterministic character.

I suggest anyone interested in understanding "Popper's three worlds" might usefully compare the current entry with the 'expanded entry' before the 2023 revert. Though Dominic Myers supported the revert in 2023 because the expanded entry did not have adequate sources - Dominic's stance being that every single point made needs a properly referenced source - anyone glancing at the current entry will see that it makes many, many points without offering any sources that support these points (e.g. that Popper viewed theories as merely instruments where "truth" plays no role in their evaluation).

More important perhaps than this problem of inadequate sourcing, they may also find that the current entry contains many false, misleading and dubious claims whereas the expanded entry did not.

DM ~2026-37830-04 (talk) 12:36, 2 July 2026 (UTC)

Responses to DM

"(2) "...the intrinsic value of Hamlet as a world 3 object is embodied many times in world 1" Here is what Popper wrote:

Many World 3 objects like books or new synthetic medicines or computers or aircraft are embodied in World 1 objects: they are material artefacts, they belong to both World 3 and World 1. Most works of art are like this. Some World 3 objects exist only in encoded form, as musical scores (perhaps never performed) or as gramophone records.

— Popper, 1977, The Self and Its Brain

All these are objects that belong to world 3, in my terminology; in contradistinction to a particular volume, located at a particular place, which is an object in world 1. This volume can be said to be a world 1 embodiment of a world 3 object.

— Popper, 1978, Three worlds

World 1 embodiments of world 3 objects, such as handwritten books, or printed books, or articles in journals, are extremely important; but they are important not as world 1 objects but as world 3 objects. Examples of other such world 1 embodiments of world 3 objects are: a geographical map, a plan of a building, or of an engine, or of a motor car, or of an aeroplane. Such maps or plans are based upon theories; they are, precisely like books, embodiments of world 3 objects.

— Popper, 1978, Three worlds

It was seen as important in secondary sources:

Popper distinguished ‘embodied’ and ‘unembodied’ World 3 objects (see Popper & Eccles 1977, p.41). The former include, firstly, material artefacts — such as books, furniture, clothes, utility articles, money, sculptures, and paintings — which are, simultaneously, members of both World 1 and World 3. For example, a book as a material body and a coin as a piece of metal belong to World 1: they have perceptible and measurable physical properties, such as weight, form, spatio-temporal location, colour, odour, taste, and so on.

— Niiniluoto, 2006, World 3: A Critical Defence

I will remove "intrinsic". It was used only to avoid a tautology when we think already of Hamlet as a World 1 object.
Dominic Mayers (talk) 21:00, 2 July 2026 (UTC)

Response to the following criticism:

The current entry is also deeply misleading in treating "Popper's three worlds", especially Popper's theory of "World 3", as if it were a mere add-on to his philosophy of science and was designed or developed by Popper to shore up his non-inductivist philosophy of science.
— User:DM (~2026-37830-04 )

The paper does not say that Popper introduced World 3 to address the problem of induction. The section "Objective knowledge and inductionism" provides only a context. That section says :

Already in the 1930s, Popper discussed the distinction between scientific objectivity and subjective conviction.[2] It was only decades later that Popper would refer to scientific knowledge as objective knowledge in World 3, and describe this scientific activity as an interaction between World 2 and World 3 responsible for the growth of objective knowledge.

On the other hand, the next section connect World 3 to Popper's rejection of psychologism. He introduced the concept in his paper "Epistemology without a knowing subject". In 1975, in Objective Knowledge, he wrote

And it further led me to realize that only a formulated theory (in contradistinction to a believed theory) can be objective, and to the idea that it is this formulation or objectivity that makes criticism possible ; and so to my theory of a 'third world' (or, as Sir John Eccles prefers to call it, 'world 3').

I could easily find many other passages in which Popper opposes his knowledge in World 3 to knowledge as justified true belief and to psychologism in general. And many independent sources mention that. For example

Karl Popper's search for a philosophy of science which does not rely upon induction or presume psychologism resulted in his adoption of a pluralistic metaphysic that posits three separate worlds: Wl, W2 and W3.

— Harry Reeder and Lenore Langsdorf, A PHENOMENOLOGICAL EXPLORATION OF POPPER'S 'WORLD 3', 1988

Dominic Mayers (talk) 20:07, 3 July 2026 (UTC)

DM keeps editing his criticism. I added a source. Here is an extract.

After the mid-1960s, Popper’s insistence on the objective or institutional aspect of knowledge led him to develop his theory of objective mind, or theory of World 3. In an address given in 1967 under the title ‘Epistemology without a Knowing Subject’, he distinguished for the first time between an objective or ‘third world’ approach and the ‘second world’ attitude of subjectivism: the former bases itself upon the results of cognitive activity— theories and arguments—whereas the latter approaches scientific knowledge from the psychological and behavioral side (OK: 107). This subjectivist viewpoint strikes Popper as incapable of grasping the specificity of scientific work, because it does not take into account that a theory may be discussed and evaluated only insofar as it is formulated in an objective and communicable manner, abstracting from subjective nuances and from the psychological conditions in which it was conceived and developed (OK: 26).

— Corvi, 2005

Dominic Mayers (talk) 02:00, 13 July 2026 (UTC)