Wikipedia as Illustration of the Truth-Seeking Rationale for Freedom of Expression

By Mark Cenite

Empirical evidence for the truth-seeking rationale for freedom of expression – the assertion that truth prevails in a free marketplace of ideas – is difficult to interpret. Analysis of how Wikipedia functions, and the accuracy of its content, provides preliminary indications of the validity of the truth-seeking rationale and its limits.

A rationale for protecting freedom of expression that ranks among the most cited is the truth-seeking rationale. According to this rationale, information and opinion should circulate free of government controls. The sanguine conclusion is that truth, or at least the best ideas, will prevail in the end. The evidence for this sweeping conclusion is limited and disputable, as this article demonstrates. Given the paucity of solid evidence from other contexts, this article suggests that Wikipedia can serve as an illustration of how relatively unfettered expression can lead to the best content prevailing, at least in some circumstances. 

Despite the limited evidence for it, citations of three famous sources of the truth-seeking rationale are frequent. An early expression of the rationale is from English poet John Milton’s Areopagitica (1644), his defense of free speech, in which he uses a metaphor of Truth and Falsehood wrestling and Truth winning in a fair match.1 Areopagitica has been cited 478 times in law review articles published since 1982 that are available in LexisNexis Academic; there are also 49 citations of it in federal and state cases available in the LexisNexis database from throughout United States legal history.2 Another source for the rationale is English philosopher John Stuart Mill’s On Liberty (1859), in which he advanced the argument that truth will prevail and that a side effect of the struggle to identify the truth is that participants in the debate, and those in the audience, may gain a keener appreciation of the truth that finally emerges. A search for citations of Mill’s On Liberty and “free speech” returns 1,683 hits from law reviews and 65 hits from the US cases since Mill’s publication of the work.3 Justice Oliver Wendell Holmes is often cited for the view the truth would prevail in the “marketplace of ideas”, though Holmes did not actually use the exact phrase, but instead words with similar meaning: “[T]he best test of truth is the power of the thought to get itself accepted in the competition of the market.”4 A LexisNexis search for “Holmes” and “marketplace of ideas” yields 2,979 hits in law reviews and 193 hits in cases.

In the sentence after Holmes advanced this “marketplace of ideas” rationale, he wrote that it “is the theory of our Constitution. It is an experiment, as all life is an experiment. Every year, if not every day, we have to wager our salvation upon some prophecy based upon imperfect knowledge.”5 Is the rationale merely a prophecy? What are the results of the ongoing experiment? What evidence can one cite of the free marketplace of ideas actually creating conditions in which the best ideas prevail? We shall discuss national comparisons and a famous study of the incidence of famine in liberal democracies.  Though the illustration is imperfect, we argue that analysing Wikipedia as a contemporary example of a well-functioning free market of ideas is preferable to making a statement, on blind faith, that truth emerges.

Evidence for the Truth-Seeking Rationale: National Comparisons

One might say that the truth-seeking rationale is being tested regularly, if one contrasts debates in societies that enjoy more freedom of speech with others. In free societies, does truth displace falsehood? If we simply look at the national level, there are too many confounding variables to make comparisons rigorously. The most difficult question is how to assess the outcome variables: How does one choose the variables to examine to assess which ideas are true (or best) and whether they have prevailed? A less complex but real concern is assessing the level of freedom of expression in nations; ratings and rankings of organisations like Reporters Without Borders and Freedom House are fraught with controversy for being subjective, biased, or imprecise.6

Free expression is a factor that facilitates discovery of better arrangements for distributing basic resources; the best ideas prevail, at least in this very narrow context. 

Limited evidence supporting the rationale comes from Amartya Sen, the Nobel Prize winning economist, who found that there has never been famine – widespread hunger that results in part from human error – in a functioning democracy with a free press.7 He suggested this correlation is not spurious, but may actually be a result of causation. Sen suggests that in free societies, citizens and the press take the steps necessary to intervene in the sequence of missteps that results in famine. Free expression is a factor that facilitates discovery of better arrangements for distributing basic resources; the best ideas prevail, at least in this very narrow context.  

Despite the weakness of the evidence for it, the truth-seeking rationale has become something of a cliché in free societies. The rationale has its detractors, however, such as legal scholar Alexander Bickel, who wrote, “[W]e have lived through too much to believe it”, for one must ask “whether our experience has not taught us that even such ideas [as proletarian dictatorship, segregation, or genocide] can get themselves accepted” in the marketplace of ideas.8 Legal scholar Lee Bollinger wrote that if truth emerges in the long run, it may be too late for many who suffer through the process.9 “Market failure” theorists point out that just as entirely free markets sometimes fail to produce the best outcomes and can benefit from government regulation, the marketplace of ideas can fail: lack of economic resources can prevent some from participating in debates that are controlled by wealthy media owners and dominated by voices backed by big promotional budgets.10 Sceptics of the truth-seeking rationale abound; the founding Prime Minister of Singapore, Lee Kuan Yew, was among those who emphasised that freedom of expression would lead to “a mess” unless people were sufficiently educated for a well-informed, rational debate: “This free-for-all, this notion that all ideas should contend and there will be blinding light out of which you will see the truth – ha!”11

Wikipedia as Marketplace of Ideas

Given the paucity of good tests of the truth-seeking rationale, we ask: To what extent does Wikipedia approximate a free marketplace of ideas? And to what extent do the best ideas prevail there? The tentative conclusion of this article is that Wikipedia provides suggestive evidence that a marketplace of ideas operates surprisingly well for truth discovery.

Wikipedia, founded by Jimmy Wales in 2001 and governed by the nonprofit Wikimedia Foundation, has long ranked as one of the most-visited Internet sites.12 Anyone can write or amend Wikipedia articles. A user can register for a screen name, but one of the core, immutable rules of Wikipedia is that one does not need to register for a username to make edits.13 Wikipedia mandates a “neutral point of view”: Contributors are to make articles that emphasise the facts that people agree upon and, when covering controversies, mention disagreements and attribute them to their sources.14 Users can tag content that departs from content guidelines.15 Wikipedia has administrators who have powers to do things like lock a page temporarily when users get involved in “edit wars” (repeatedly changing the content of a page)16 or when “vandalism” occurs, including violations of guidelines such as adding abusive language, nonsense, or personal attacks to an entry.17

Is Wikipedia a Functioning Free Market of Ideas?

No one claims Wikipedia is perfect, and the ease with which one may make changes has been the target of jokes and critiques.18 How well does Wikipedia approximate a free exchange of ideas? Contributions might be likened to a grand debate in the town square among all who wish to contribute – no matter how ridiculous, misguided or inaccurate their views. As in a debate, there is no guarantee that one’s contributions will be accepted. Users are encouraged to correct each other’s errors, update information, and to call attention to bias. The difference from a debate is that in Wikipedia the conclusion is digitally written down, and collectively edited and rewritten, to reflect at least a temporary consensus.

Wikipedia is like a free marketplace of ideas in that it lacks vetting at the point that a contribution is made.

Wikipedia is like a free marketplace of ideas in that it lacks vetting at the point that a contribution is made. In free speech jurisprudence, the most disfavoured type of censorship is prior restraint, a kind of censorship in which content is vetted and suppressed (or restrained) prior to its circulation; subsequent punishment (after publication) is seen as a preferable way to control expression, and better yet is no punishment at all, but simply more debate on the issue (sometimes called “counter-speech”).19 On Wikipedia there is an absence of anything remotely analogous to prior restraint – there is not any sort of editorial vetting of content prior to circulation. There is also absence of prior restraint in a more classic legal sense on Wikipedia: Wikipedia generally does not carry out the many requests from governments around the world to remove content.20  Government agents can make their own alterations to content, but they are individual users like any others.21

The comparison of Wikipedia to the free press is an imperfect analogy. However, the freedom of Wikipedia contributors from any constraints – freedom from editing before publication as well as freedom from government censorship – creates a platform that may be one of the closest approximations of an international free marketplace of ideas.

Does the Best Content Prevail on Wikipedia

In a free marketplace of ideas, truth is supposed to prevail, according to this rationale. Does it? There is limited but encouraging evidence regarding the factual accuracy (the truth or falsehood) of the entries. In a frequently-cited study published in Nature, experts compared the entries on 42 scientific topics in Wikipedia and in the Encyclopedia Britannica, whose articles are written by paid subject experts.22 For example, both sources’ articles about the centre of our solar system, the sun, were examined. Across the pairs of articles, there were four errors in each source that were judged serious. On average, each of the Britannica articles contained 3 errors that were judged minor, compared to 4 minor errors in each Wikipedia article. Wikipedia is different in other ways, however; entries are far more up-to-date, and its scope is more comprehensive.

In a 2012 preliminary study conducted by Wikimedia Foundation in cooperation with Oxford University, Wikipedia articles in multiple languages were compared to entries in other encyclopedias in those languages. Across multiple disciplines, expert judges found Wikipedia articles superior in accuracy and references, though Wikipedia was weaker in style and overall ratings for some articles.23 The Journal of Oncology Practice also found similar accuracy of Wikipedia entries and a professionally edited database of medical information, though Wikipedia was judged less readable.24

What to conclude from these studies? Wikipedia’s free marketplace of ideas seems to have produced a high standard of accuracy compared to expert authors. Lower readability and style ratings for Wikipedia, plus the slightly higher rate of minor errors in one study, are perhaps compensated for by the more comprehensive and up-to-date coverage.

Preliminary Conclusions

Wikipedia provides a useful example for teaching and for illustrating the truth-seeking rationale in action because its input is free of any sort of restraints and the output is high quality. Because it is designed to allow contributors freedom from central control, and because its operators resist efforts to censor it, Wikipedia operates as an ongoing test of the whether truth prevails when, to paraphrase Milton, truth and falsehood grapple freely. So far, the accuracy of Wikipedia has proven reassuringly comparable to other sources that are authoritative by traditional measures.

Wikipedia provides a useful example for teaching and for illustrating the truth-seeking rationale in action because its input is free of any sort of restraints and the output is high quality.

Wikipedia’s “edit wars” and “vandalism” are also potentially revealing. Perhaps crowdsourcing of the truth in a free marketplace of ideas works best when more neutral subjects are involved, such as the mundane scientific entries about the sun in the Nature study. But when matters of passionate dis-agreement are involved – such as articles about controversial figures like Donald Trump – Wikipedia’s authorities, its editors, intervene in the free market and block some contributors or lock the page. Once again, the comparison to regulation is thought-provoking; even in many relatively free societies, regulations control some kinds of expression, including offensive content. The rare instances in which Wikipedia’s editors intervene suggest that the marketplaces of ideas may function best when it is relatively, but not completely, free.

About the Author

Mark Cenite is Associate Chair (Academic) at the Wee Kim Wee School of Communication & Information, part of Nanyang Technological University in Singapore. He has a law degree from Stanford Law School and a PhD in Communication from the University of Minnesota. He is a winner of multiple awards for teaching Law in Singapore, and has also taught Law in the United States and Hong Kong. 


1. “And though all the windes of doctrin were let loose to play upon the earth, so Truth be in the field, we do injuriously, by licencing and prohibiting to misdoubt her strength. Let her and Falshood grapple; who ever knew Truth put to the wors, in a free and open encounter.” John Milton, Areopagitica(1644).
2. Results reported here were from searches conducted on 19 September 2016 in the LexisNexis database in the category “US Law Reviews and Journals” from all available dates (since 1982), and in the category “US Federal & State Cases” from all available dates. The search term used was simply the title “Areopagitica.”
3. The search terms were “Mill” within 5 words (/5) of “On Liberty” and the term “free speech”.
4. Abrams v. United States, 250 U.S. 616, 630 (1919) (Holmes, J., dissenting).
5. Abrams, 250 U.S. 616, 630 (Holmes, J., dissenting).
6. Reporters Without Borders is available at; Freedom House is available at A podcast criticising the methodology of Reporters Without Borders is Bob Garfield’s interview with Max Fisher, “No, US press freedom is not in dire decline,” WNYC’s On The Media, Feb. 14, 2014, at
7. Amartya Sen, Development as Freedom(1999).
8. Alexander Bickel, The Morality of Consent71, 76-77 (1975).
9. Lee C. Bollinger, The Tolerant Society74 (1986).
10. Jerome A. Barron, Access to the Press: A New First Amendment Right, 80 Harv. L. Rev. 1641-1678 (1967).
11. “Intellectual Free-For-All Not for the Masses, Says SM Lee,” Business Times (Singapore) (Oct. 6, 1995).
12. See Alexa Internet,
13. “Wikipedia: Rules,”
14. “Wikipedia: Neutral point of view,”
15. “Wikipedia: Tagging pages for problems,”
16. “Wikipedia: Edit War,”
17. “Wikipedia: Vandalism,”
18. “Will Wikipedia Mean the End Of Traditional Encyclopedias?” The Wall Street Journal (Sept. 12, 2006).
19. Thomas I. Emerson, The Doctrine of Prior Restraint, 20 Law and Contemporary Problems648-671 (1955), at:
20. Wikimedia reports that Wikipedia received 243 requests to take down content from January through June of 2016 and none were granted. See
21. There are some caveats to the argument that Wikipedia is free of government control, for authorities can of course punish contributors in their jurisdictions, and nations including China block Wikipedia, thus blocking not only readers but contributors. See Jimmy Wales, “State of the Wiki: Free Expression and Wikipedia,” speech at Wikimania 2015, at
22. Jim Giles, Internet Encyclopaedias Go Head to Head, 438 Nature900-901 (15 December 2005).
23. Imogen Casebourne, Chris Davies, Michelle Fernandes, & Naomi Norman (2012), Assessing the Accuracy and Quality of Wikipedia Entries Compared to Popular Online Encyclopaedias: A Comparative Preliminary Study across Disciplines in English, Spanish and Arabic. Retrieved from:
24. Malolan S. Rajagopalan, Vineet K. Khanna, Yaacov Leiter, Meghan Stott, Timothy N. Showalter, Adam P. Dicker & Yaacov R. Lawrence, Patient-Oriented Cancer Information on the Internet: A Comparison of Wikipedia and a Professionally Maintained Database. 7 Journal of Oncology Practice 319-323 (2011), at

The views expressed in this article are those of the authors and do not necessarily reflect the views or policies of The World Financial Review.