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Extended Knowledge Overextended?

Part of the Palgrave Studies in Comparative East-West Philosophy book series (PSCEWP)


It is undeniable that computer technology has had a major impact on how we engage enquiry. We use computer devices to store information that helps us in our daily lives—just think of the contacts on your phone and whatever calendar app you might use to keep track of your schedule. Furthermore, people enjoy easy and quick access to a wide range of reliable online resources such as Nature, Reuters, and Encyclopedia Britannica through their laptops or smartphones. Powerful search engines such as Google open up the door to swaths of information, enabling people easily to acquire a wide range of true beliefs through reliable means about all kinds of subject matters. However, what is the status of such true beliefs? In particular, once beliefs cease to be occurrent, do we still have non-occurrent beliefs, and, if true and reliably sustained, do they still qualify as knowledge? If they do, we would have cases of extended belief and knowledge, as these computer devices go beyond onboard capacities such as perception and memory. However, unlike our beliefs and desires, many information-storing apps and resources do not have the capacity automatically to “update” their information in light of new information. Moreover, wouldn’t extended belief and knowledge lead to massive cognitive bloat—an unpalatable explosion of belief and knowledge completely detached from an ability naturally to recall the relevant information? It would seem so given the wide variety of storage repositories and devices (literally) at one’s fingertips (online journals, Dropbox, Google, stored telephone contacts). Doesn’t cognitive bloat threaten to undermine the notion of expertise? Is it really possible to become an expert on a given topic by simply and easily looking up information via one’s smartphone and saving it? And where, now, would we place cognitive effort—steps taken by individuals to commit details to memory, to apply knowledge, to deliberate, and to assess and reflect? In “Extended Knowledge Overextended?”, Nikolaj Jang Lee Linding Pedersen and Jens Christian Bjerring offer a comprehensive discussion of extended belief and knowledge. They criticize two recent attempts to mitigate concerns about cognitive bloat by arguing that their effectiveness is contingent on the current state of technology—in particular, the fact that computer devices are currently external to us. However, if computer devices seamlessly integrated with our own onboard capacities—the so-called neuromedia—become reality, it may be much more difficult to resist extended belief and knowledge and, with them, massive cognitive bloat.

We are grateful to Davide Fassio, Jie Gao, Walter Hopp, Masashi Kasaki, Kevin Lynch, and Søren Overgaard for comments. We are likewise grateful to Karyn L. Lai for her great work as the editor of this collection. A special thanks goes to Mog Stapleton for providing feedback on an earlier version of the chapter. Her feedback prompted a substantial expansion of the introduction and considerable trimming of the other sections.

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  1. 1.

    For technical background, see Musk (2019)—a whitepaper on Neuralink. The full one-hour session is available at the Neuralink YouTube channel (

  2. 2.

    Interview at the Code Conference in 2016 (; 56:50 onward).

  3. 3.

    Interview at the Code Conference in 2016 (; 58:50 onward).

  4. 4.

    Interview at the Code Conference in 2016; launch presentation livestreamed on Neuralink’s YouTube channel on July 16, 2019 (

  5. 5.

    See also Chalmers (2008), the foreword to Clark’s Supersizing the Mind (2008). Chalmers’ 2011 TEDxSydney talk was entitled “Is Your Phone Part of Your Mind?” and gives the same argument ( Musk has said repeatedly in interviews that we are already cyborgs—see, e.g., the interview at the Code Conference 2016 (; 58:50 onward).

  6. 6.

    In Bjerring and Pedersen (2014), we talked about this consequence of the extended mind thesis in terms of restricted omniscience : a person enjoys restricted omniscience with respect to a particular, fairly specific subject matter—say, past Academy Award winners or NBA standings and statistics—if the person has complete (or close to complete) extended knowledge with respect to that subject matter.

  7. 7.

    Put differently, computer devices can result in a significant upgrade to your biological memory. Earlier we spoke of boosting memory through neuromedia, and here we say that computer devices, whether external or internal, can result in a memory upgrade. It is important to qualify this. We are not saying that human memory is small. It is widely agreed that it is huge—about 2.5 petabytes (or a million gigabytes). The totality of our memories takes up much, much more space than what is available on smartphones and other computer devices we have access to. There are many types of memories and different ways that they are stored. What we have in mind when making the upgrade-related claims is quite specific: think of how much text you can store on a regular laptop or smartphone. Now consider whether you could store all of that information and retrieve it from biological memory. Probably not. Computer memory involves an upgrade in the sense that, counting it as yours, it puts you in a position to recall many things that you would otherwise not be able to recall.

  8. 8.

    See also Rubert (2004, Sect. IV) and Sprevak (2009, Sect. V).

  9. 9.

    Interestingly, this complaint suggests the existence of an intimate connection between the qualitative and quantitative significance of cognitive extension: non-onboard capacities and resources such as notebooks and external computer devices do not support extended belief because it would imply massive cognitive bloat. A point about the quantity or scale of cognitive extension supports a substantial qualitative conclusion.

  10. 10.

    Clark and Chalmers (1998: 17). Our formulation of the three first conditions follows Clark (2010: 46). The label “trust and glue” is due to Clark.

  11. 11.

    Clark and Chalmers (1998: 17).

  12. 12.

    See, e.g., Kelp (2013), Pritchard (2010), Palermos (2011, 2014, 2015). As for examples of extended cognition, think of the game Tetris, where buttons are used to rotate figures in order to determine whether they fit into empty slots in a structure, or the task of determining the product 13 × 17 by using a calculator. According to Clark and Chalmers, the following parity principle forces a nondiscriminatory approach to internally and externally driven cognition: “If, as we confront some task, a part of the world functions as a process which, were it done in the head, we would have no hesitation in recognizing as part of the cognitive process, then that part of the world is (so we claim) part of the cognitive process” (Clark and Chalmers 1998: 8). Since we would not hesitate to take mental rotation and mental calculation as part of the cognitive process, we should not hesitate to recognize the external devices as part of the cognitive process either. Cognitive processes thus extend into the external environment.

  13. 13.

    Classic works on reliabilism include Goldman (1979, 1986). It is standard also to include a no-defeaters condition. We leave it out here for ease of exposition. However, nothing hangs on this simplification, as the arguments and considerations satisfy this type of condition or can be straightforwardly modified to do so.

  14. 14.

    Bjerring and Pedersen (2014: 27).

  15. 15.

    Bjerring and Pedersen (2014: 30).

  16. 16.

    The Lone case is like the case called “Cut and Paste” in Bjerring and Pedersen (2014: 29), except that it makes explicit the subject’s attitude toward the existence and reliability of the information-sustaining source. This added layer of explicitness will the helpful for the purposes of our discussion in Sects. 5 and 6.

  17. 17.

    Other discussions of cognitive bloat or intimately related issues include Allen-Hermanson (2013), Carter and Kallestrup (2020), Farkas (2012), Ludwig (2015), Lynch (2014, 2016), Pritchard (2010, 2018a, b, c), Smart (2012), Sprevak (2009, 2019), and Wikforss (2014). More on Wikforss (2014) and Carter and Kallestrup (2020) below.

  18. 18.

    Wikforss (2014, Sect. 3).

  19. 19.

    See, e.g., Shah and Velleman (2005).

  20. 20.

    Wikforss (2014: 469).

  21. 21.

    Wikforss (2014: 470–471).

  22. 22.

    The functional role of belief in explaining action together with desire relates to practical reasoning. As just seen, Wikforss argues that the information in Otto’s notebook is unfit to feature in practical reasoning in the way that beliefs are supposed to do. She further argues that the information in the notebook is unfit to play the role of belief in theoretical reasoning. See Wikforss (2014: 472–474).

  23. 23.

    Wikforss (2014: 475).

  24. 24.

    Pritchard (2018a: 329).

  25. 25.

    Lynch uses the term “Google knowledge” for the kind of knowledge generated through neuromedia. He is keen to emphasize that we should be critical of such knowledge and recognize its limitations—in particular, that it fails to deliver understanding. For a book-length discussion of this issue, see Lynch (2016). Pritchard likewise argues that we need to recognize the limitations of knowledge generated through external devices or neuromedia. Among other things, even if they result in swaths of knowledge, this type of knowledge does not contribute toward achievement of the chief epistemological aim of education: to build intellectual character. This aim, according to Pritchard, is a matter of cultivating and exercising onboard capacities. See Pritchard (2018a) for an extended argument to this effect. Interesting as they may be, we have relegated these observations to a footnote because what matters for present purposes is the fact that both Lynch and Pritchard grant that neuromedia sustain belief.

  26. 26.

    The answer to Lone+’s question is, of course, “Esbjerg Forenede Boldklubber”—or “EFB” for short. During the 1978–1979 season, EFB accumulated 46 points, claiming the championship with a convincing 6-point margin and a goal difference of 29 goals (59 for, 30 against). One author strongly approves of the content of this footnote—the other less so.

  27. 27.

    Carter and Kallestrup (2020: 879).

  28. 28.

    Carter and Kallestrup (2020: 881).

  29. 29.

    Carter and Kallestrup (2020: 879, 881).

  30. 30.

    Carter and Kallestrup (2020: Sect. 2, 882).

  31. 31.

    Carter and Kallestrup (2020: 881–882).

  32. 32.

    Carter and Kallestrup (2020: 872, 881). See also their comments in note 18. Carter and Kallestrup’s MEMORAID case (2020: 873) involves meta-incoherence about the origin of the subject’s beliefs. We return to the MEMORAID case below.

  33. 33.

    Carter and Kallestrup (2020: 882). In the extensive body of work on the value problem, it is widely assumed that knowledge is more valuable than any epistemic standing that falls short of knowledge. See, e.g., Carter and Jarvis (2012), Greco (2009), Kvanvig (2003), Pritchard (2007), and Pritchard et al. (2018). Greco is a prominent advocate of the idea that knowledge is a cognitive achievement (2003, 2010, 2013). Another prominent advocate is Sosa (2007). Both Greco and Sosa likewise endorse the ability intuition, that is, the idea that S’s true belief that p can only qualify as knowledge if the belief is due (at least to a considerable extent) to S’s cognitive ability. Furthermore, they take achievement and ability to be intimately related: knowledge is a cognitive achievement because it is due to ability.

  34. 34.

    Carter and Kallestrup (2020: 880).

  35. 35.

    Carter and Kallestrup (2020: 880). They also argue that Telo does not satisfy the condition of typical invocation (i.e. C1). We leave this aside for present purposes.

  36. 36.

    Carter and Kallestrup (2020: 880–881).

  37. 37.

    Carter and Kallestrup (2020: 873–874).

  38. 38.

    Carter and Kallestrup (2020: 882).

  39. 39.

    Greco (2003, 2010, 2013), Sosa (2007).

  40. 40.

    Prominent advocates of sensitivity include Dretske (1971) and Nozick (1981). Prominent advocates of safety include Pritchard (2005), Sosa (1999), and Williamson (2001).


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Pedersen, N.J.L.L., Bjerring, J.C. (2022). Extended Knowledge Overextended?. In: Lai, K.L. (eds) Knowers and Knowledge in East-West Philosophy. Palgrave Studies in Comparative East-West Philosophy. Palgrave Macmillan, Cham.

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