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A Contextualist Solution to the Demarcation Problem

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In this paper, after presenting three challenges that any knowledge-based demarcation between science and non-science should meet, namely, the skeptical, triviality, and mimicry challenges, I show how a recent contender in epistemology, viz., presuppositional epistemic contextualism, allows these challenges to be met, hence pointing toward a novel solution to the perennial demarcation problem.

Conceiving of scientific knowledge from the vantage point of contextualism forces us to consider science as being first and foremost a distinctive epistemological context, which has the peculiarity of coming with a very high degree of stringency for the truth conditions of putative knowledge attributions. The fact that science imposes particularly stringent norms on knowledge is measured by the extension of the set of counterpossibilities that science is (i) in the business of eliminating on the basis of available evidence and (ii) ready to take seriously (insofar as they are consistent with the scientific community’s pragmatic presuppositions at a given time and place).

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  1. Note that knowledge will only be considered here as “first-order knowledge”, that is, knowledge of worldly things, broadly conceived. Hence, endeavors that fall short of producing this type of knowledge (for instance—and perhaps—philosophy itself; Beebee 2018) and/or that produce “second-order knowledge” (that is, knowledge about putative “items” of knowledge such as views, beliefs, and theories) will ipso facto be considered non-scientific. Without presuming that science doesn’t deal with second-order knowledge, I take it as a reasonable working hypothesis, which, incidentally, is generally tacitly assumed in the demarcation debate, that science essentially strives to produce knowledge about things external to itself.

  2. As the proposed illustration is only meant to ease understanding, I remain silent on some possible technicalities in order not to obscure the main point (like, e.g., the fact that the hands in question are presumed to be attached to a body, etc.).

  3. Actually, the closure claim will be considered as true only under certain conditions, i.e., when “context” is actually held fixed, hence the expression “mostly” in parentheses.

  4. Note that the solution proposed in this paper will not be applied to what could have been dubbed the “error challenge”, which concerns demarcating between genuine science and “bad” science, which is understood, not as pseudoscience, but as the exercise of fraud, mistakes, shortcomings or other deviant behaviors that may occur within science itself. Tackling this issue will have to wait for another occasion.

  5. Such an observation is what led Lewis (1996) to conclude that epistemology, being such a context, “destroys” knowledge (not tout court, but within the bounds of such a specific context that is epistemology; see DeRose 2000). Note that, in a very Cartesian spirit, one may consider here that I at least know that I am currently thinking, but this knowledge falls short of meeting the externality condition that is assumed here (see footnote 1).

  6. Sticking to the previous convention, “knowsC” indicates “knows in context C”.

  7. The very fact that I added the “m” and “s” subscripts here already points toward what could have been Lewis’ response to this caveat, namely, that knowledge is never “destroyed” or impossible as such, but is only “destroyed” in contexts that we may easily dismiss as too paranoiac. Independently of whether Lewis himself would agree with such a response, it remains that his initial account makes any counterpossibility, however far-fetched, too easy to suddenly become relevant (and hence force a shift in context).

  8. Following Blome-Tillmann (2014, 23 and 26), a finer-grained analysis of this idea is as follows: x pragmatically presupposes p in C if and only if x is disposed to behave, in her use of language, as if she believes p to be common ground in C, and p is common ground in a group G if and only if all members accept (for the purpose of the conversation, within a fixed context) that p, and all believe that everyone accepts that p, and all believe that everyone believes that all accept that p, etc.

  9. Some side remarks: (i) PEC is, as such, a meta-theory of knowledge. It does not consist per se of a thorough analysis of what knowledge is or is supposed to be and is actually consistent with many (first-order) theories of knowledge. (ii) Although I am mostly interested here in the Rule of Attention and one of its recent amendments, other rules are active and implicit in PEC; however, these rules will not be discussed here. (iii) Although PEC is a factive (meta)theory (in the sense that, if x knows that p, then p, which is guaranteed by Lewis’ “Rule of Actuality” (1996, 554)), it does not make truth part of the definiens of knowledge, a feature that makes it amenable to a fallibilist take on science.

  10. Here, the subscript “sc” indicates “scientific”.

  11. The procedure described here for calculating an international standard of time is not entirely faithful to what is actually the case. However, because the procedure has been simplified for the sake of exposition, it only strengthens the point being made.

  12. It is important to defuse a possible confusion here. It is not the context-sensitivity of the predicate “flat” that will be at stake in what follows, but the context-sensitivity of the verb “know” in the corresponding knowledge attribution of the form: “x knows that the Earth is flat”. I thank an anonymous reviewer for bringing up this point to my attention.

  13. Note that, in this specific toy scenario, flat Earth theory wouldn’t even produce true knowledge claims within today’s mundane context, which is indeed already too strict. Taking EC at its limit, one could make a case that neolithic cavemen knew that the Earth was flat, for then they lacked any sensitive evidence to the contrary (to the effect that the Earth’s flatness did not conflict with any of their pragmatic presuppositions). But it would be a stretch to consider such a degenerate “cavemen” context as scientific (and hence possibly pseudoscientific), as it clearly lacks the appropriate level of sophistication.

  14. Here in the specific sense of “ignoring” introduced in Sect. 4.3, which is consistent with the fact that our pseudo-astronomer is “attending to” or “considering” the counterpossibilities at stake.


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I would like to thank the audiences of the 2022 SoPhA triennial meeting in Neuchâtel, the JHPS seminar at École normale supérieure in Paris, the 2023 conference Les rencontres de Venise in Venice, the IHPST general seminar of Paris 1 Panthéon-Sorbonne, as well as the “VulPhi” workshop at the University of Namur for their interesting feedbacks on presentations on this topic. I also thank Martha Evonuk, PhD, from Evonuk Scientific Editing ( for editing a draft of this manuscript.

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Sartenaer, O. A Contextualist Solution to the Demarcation Problem. J Gen Philos Sci (2023).

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