Skip to main content
SpringerLink
Log in

Externalism and “knowing what” one thinks

  • Published:
Synthese Aims and scope Submit manuscript

Abstract

Some worry that semantic externalism is incompatible with knowing by introspection what content your thoughts have. In this paper, I examine one primary argument for this incompatibilist worry, the slow-switch argument. Following Goldberg (Pac Philos Quart 87:301–314, 2006), I construe the argument as attacking the conjunction of externalism and “skeptic immune” knowledge of content, where such knowledge would persist in a skeptical context. Goldberg, following Burge (J Philos 85(1):649–663, 1988), attempts to reclaim such knowledge for the externalist; however, I contend that all Burge-style accounts (at best) vindicate that a subject can introspectively know that she is thinking that “water is wet.” They do not yet show how a subject can introspectively know what she is thinking—which is the distinctive type of knowing at issue in the slow-switch argument. Nonetheless, I subsequently amend the Burge-style view to illustrate how an externalist can introspectively “know-what” content her thought has, and know it in a skeptic immune manner, despite what the slow-switch argument may suggest. For one, I emphasize that “knowing what” can be ontologically non-committal (so that knowing your thought is about water does not require knowing that water exists). For another, following Boer and Lycan (Knowing who, 1986), I stress that “knowing what” is purpose-relative–and for at least some purposes, it seems possible for the externalist to “know what” content her thought has, even if skeptical hypotheses about XYZ are relevant.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Notes

  1. See Putnam (1973, 1975), McGinn (1977), Stich (1978), and Burge (1979, 1982, 1986). There are differences between these authors, but nothing in what follows depends crucially on the details.

  2. In discussing self-knowledge, I vary between talk of “knowing what content a thought has” and “knowing what one thinks.” The former states most clearly what is at issue, but it can be awkward rhetorically. Thus the latter occasionally replaces the former.

  3. A thought is “de \(\hbox {H}_{2}\hbox {O}\)” when its object is \(\hbox {H}_{2}\hbox {O}\); and it is such even if it is opaquely ascribed as a “water” thought. Thus. ‘Bob thinks that water is wet’ does not entail ‘Bob thinks that \(\hbox {H}_{2}\hbox {O}\) is wet’, yet both sentences still ascribe thoughts that are de water/\(\hbox {H}_{2}\hbox {O}\). Also, n.b., ‘knowing whether’ is not straightforward either (see Lewis 1982), yet it is typically not purpose-relative like ‘knowing what’ (cf. §4). Here, ‘knowing whether’ can be seen as shorthand for: Either Oscar knows that his thought is de \(\hbox {H}_{2}\hbox {O}\) and not XYZ, or he knows that his thought is de XYZ and not \(\hbox {H}_{2}\hbox {O}\). (Compare with Kallestrup 2009 and Stanley 2011 on Schaffer’s 2007 “convergent knowledge” problem.)

  4. Burge uses the self-referring ‘with this very thought’ in lieu of ‘forthwith’. However, self-reference is potentially problematic here (see Parent 2007). In contrast, ‘forthwith’ does not self-refer, but rather refers only to the first-order thought that follows it. (Also, ‘I’ in (SV) should be read as an essential indexical; see Perry 1979. Though for the record, I doubt that anything genuinely indexical explains Perry’s examples; see Millikan 2001, 2012)

  5. Here, ‘think’ does not mean ‘believe.’ Rather, to ‘think’ that \(p\) is to have some propositional attitude with the content \(p\), but it does not imply any particular attitude.

  6. Brown perhaps makes the point most forcefully, though there is some precedent in Warfield (1992).

  7. A similar intuition is expressed in Gertler (2000).

  8. E.g., Burge (1988) likens the “directness and certainty” of (SV) to the cogito (p. 649).

  9. Perhaps the subject can answer (Q), if she knows that “XYZ” is just a fiction made up by Putnam in the 70s. But ‘XYZ’ is here acting as a placeholder for any conceivable “twin” of \(\hbox {H}_{2}\hbox {O}\). Brueckner (op. cit.) also rightly notes that (Q) is not the same question as the more simplistic “Is your thought de water or de some kind of ‘fake water’?” After all, Oscar can know immediately that the answer to the latter has to be ‘water’ (regardless of whether he speaks English or Twin-English). Still, this does not mean he is in a position to answer (Q).

  10. An anonymous referee poignantly asks why (1*) is any less troublesome for a content internalist (if ‘externalism’ in the antecedent is replaced by ‘internalism’). This is an important question; however, for present purposes, we need not pursue it here. Granted, if the trouble arises on both sides, then it does not provide an advantage to internalism. Yet this does not mean the slow-switch argument loses all interest. Even if the problem is not unique to the externalist, it is still a problem that ideally she would want resolved. Also, there is dispute among externalists on whether a conclusion like (3*) must be accepted. (E.g., Millikan’s 1993 externalism suggests that it must.) In this connection too, the present paper argues that an externalist need not acquiesce to (3*) or related skeptical conclusions about introspective self-knowledge.

  11. Does a skeptic need to defend (1*)? He may claim that the burden is on me to rule it out. For if its truth is epistemically possible, then it is similarly possible, per (1*)–(3*), that I don’t Know what I think. And that suggests I don’t really Know. This last bit may assume a KK-thesis, but perhaps that too is my burden to rule out. Admittedly, I cannot settle disputes about KK here. But I would argue that they turn the skeptic into a mere “simple skeptic,” in DeRose’s (1995) sense, i.e., a skeptic who dogmatically (!) says that we don’t know. For KK alone suffices for a skeptical regress. So to presume KK without argument is really just to prejudge that we don’t know.

  12. As a fourth objection, some have protested that the View requires too much of the ordinary person to introspectively self-know. But the View gives only a sufficient condition for one type of self-knowledge; it is not stating a necessary condition on all self-knowledge.

  13. A fifth objection is that if we know what we think, then we know that we think. Yet we should not be able to refute eliminativism just via introspection. Some mentalists reply by denying the “epistemic closure” assumed in this (e.g., Dretske 2003). Though one could instead reply that talk of “thinking” here is only instrumental, hence, ontologically neutral (cf. Dennett 1975).

  14. I have since discovered that the knowing-what vs. knowing-that distinction has been noted (albeit briefly) by Goldberg (2003) and by Burge (1998). Yet Goldberg claims that slow switching debunks “knowing what” one thinks (although not “knowing that”) (p. 253). In contrast, I argue that some “knowing what” remains viable. Burge concurs with this, but supports it via his theory of preservative memory (p. 362). In contrast, I will argue the point via the purpose-relativity of “knowing-what.”

  15. If there is concern that the description here is neither definite nor rigid, we can instead talk of “the possible liquid that appears to me as if it is in lakes, etc.;” cf. Searle (1983), Chap. 8. Yet unlike Searle, I am neutral on whether this fixes a narrow content. (The (SV)-judgment is self-verifying regardless.) N.B. to elude ontological commitment, the quantifier in ‘the liquid’ must also be read as ontologically netural; see Azzouni (2007) for more on neutral quantifiers. Besides skeptical doubts, ontological neutrality is also important to avoiding McKinsey-type problems for externalist self-knowledge; see McKinsey (1991), Brown (1995), Boghossian (1997) and Besson (2012).

  16. Yet primary intensions are not identified with descriptive contents; they are instead defined on worlds “considered as actual.”

  17. Against Boer and Lycan, Braun (2006) argues that the purpose-relativity of ‘knowing what’ attributions are not in the semantics, but rather in the pragmatics or speech-act content. This is not the place to adjudicate this dispute, yet one might note that purpose-relativity seems characteristic of “knowing what” attributions in thought as well, where the notion of a speech-act has no application. (Cf. Heal 1994; Green 2005 on Moore’s paradox.) For more on the Boer–Lycan v. Braun dispute, and on knowing-wh in general, see Parent (2014).

  18. What follows is not intended as serious Descartes scholarship; the point is just to consider whether externalism allows the sort of self-knowledge claimed in the Meditations.

  19. This indicates that the skeptic here is also not challenging the more obvious judgments of consistency. But that too is consistent with the skeptic being an external world skeptic.

  20. For convenience, I am glossing over the distinction between knowing for certain that the (SV)-judgment is true, versus knowing (SV) itself for certain. The distinction doesn’t seem to affect the present situation.

  21. An anonymous referee reminds me that some parts of Frege look favorable to content internalism, though other parts seem rather externalist. Regardless, my point is just that there is some pressure toward externalism in Frege, and that creates a tension with Cartesianism. But granted, such a tension may have existed in Frege’s work itself.

  22. Lest we think Fregeanism is unmotivated, consider that the meaning or content of a concept wholly explains why it refers to water as opposed to (say) alcohol, elephants, etc. But if content fully explains why the concept denotes what it denotes, then content apparently determines what a concept refers to. qed. Note also that even if externalism is rejected, an internalist would still need to combat the externalist’s content skeptic. After all, the internalist does not have skeptic immune knowledge of internalism. In this respect, the compatibility of externalism and introspective self-Knowledge is of direct concern even to an internalist.

  23. Boer and Lycan use ‘knows-true’ rather than ‘knows’; this is because \(^{\ulcorner }\Phi (\uppsi )^{\urcorner }\) is a representation, and is a bit misleading to talk of S “knowing” a representation. It suggests a kind of de re knowledge of the representational vehicle as such. Even so, to say that S ‘knows-true’ a representation is not to attribute meta-representational knowledge of the truth of the representation. Instead, “It is for the token to perform the sort of job...which distinguishes beliefs from desires, intentions, and other attitudes” (p. 185, n. 4).

  24. What counts as an “ability” is not obvious; I would refer the reader to Millikan (2004, Chap. 4). Boer and Lycan do not explicitly mention abilities in their official account. But this may owe to their restricting the account to theoretical purposes, viz., information-gathering and such. When they speak more broadly about their view, they hint at the ability-entailing idea above. E.g., S is said to know who N is relative to such-and-such goal iff S knows an answer with “the information about N that the questioner needs in order to carry out his project” (p. 26, emphasis mine). Still, I do not wish to commit them to such a view; this is only to illustrate that the ability-entailing idea seems to be a natural way to extend their remarks.

  25. I thank Dorit Bar-On, Thomas Hofweber, Ram Neta, Keith Simmons, three anonymous referees, and especially William Lycan for helpful comments on earlier drafts. I also thank audiences at Vanderbilt University, and at the University of North Carolina, Chapel Hill for their feedback.

References

  • Azzouni, J. (2007). Ontological commitment in the vernacular. Noûs, 41(2), 204–226.

    Article  Google Scholar 

  • Bar-On, D. (2004). Speaking my mind: Expression & self-knowledge. Oxford: Oxford University Press.

    Book  Google Scholar 

  • Besson, C. (2012). Externalism and empty natural kind terms. Erkenntnis, 76, 403–425.

    Article  Google Scholar 

  • Boer, S., & Lycan, W. (1975). Knowing who. Philosophical Studies, 28, 299–344.

    Article  Google Scholar 

  • Boer, S., & Lycan, W. (1986). Knowing who. Cambridge, MA: Bradford Books.

    Google Scholar 

  • Boghossian, P. (1989). Content and self-knowledge. Philosophical Topics, 17, 5–26.

    Article  Google Scholar 

  • Boghossian, P. (1997). What the externalist can know apriori. Proceedings of the Aristotelian Society, 97, 161–175.

    Article  Google Scholar 

  • Brown, J. (1995). The incompatibility of anti-individualism and privileged access. Analysis, 55(3), 149–156.

    Google Scholar 

  • Burge, T. (1979). Individualism and the mental. Midwest Studies in Philosophy, 4, 73–121.

    Article  Google Scholar 

  • Burge, T. (1982). Other bodies. In A. Woodfield (Ed.), Thought and object (pp. 97–120). New York: Oxford University Press.

    Google Scholar 

  • Burge, T. (1986). Intellectual norms and the foundations of mind. The Journal of Philosophy, 84, 697–720.

    Article  Google Scholar 

  • Burge, T. (1988). Individualism and self-knowledge. The Journal of Philosophy, 85(1), 649–663.

    Google Scholar 

  • Burge, T. (1998). Memory and self-knowledge. In P. Ludlow & N. Martin (Eds.), Externalism and Self-knowledge (pp. 351–370). Stanford: CSLI Press.

  • Braun, D. (2006). Now you know who Hong Oak Yung is. Philosophical Issues, 16, 24–42.

    Article  Google Scholar 

  • Brown, J. (2004). Anti-individualism and knowledge. Cambridge, MA: MIT Press.

    Google Scholar 

  • Brueckner, A. (1999). Difficulties in generating skepticism about knowledge of content. Analysis, 59(1), 59–62.

    Article  Google Scholar 

  • Chalmers, D. (1996). The conscious mind. New York: Oxford University Press.

    Google Scholar 

  • Chalmers, D. (2002). The foundations of two-dimensional semantics. In M. Garcia-Capintero & J. Macia (Eds.), Two-dimensional semantics: Foundations and applications (pp. 55–140). New York: Oxford University Press.

    Google Scholar 

  • Cohen, S. (1986). Knowledge and context. The Journal of Philosophy, 83, 574–583.

    Article  Google Scholar 

  • Cohen, S. (1998). Contextualist solutions to epistemological problems: Skepticism, Gettier, and the lottery. Australasian Journal of Philosophy, 76, 289–306.

    Article  Google Scholar 

  • Dennett, D. (1975). True believers: The intentional strategy and why it works. In A. F. Heath (Ed.), Scientific explanation: Papers based on Herbert Spencer lectures given in the University of Oxford (pp. 53–75). Oxford: Clarendon Press.

    Google Scholar 

  • DeRose, K. (1995). Solving the skeptical problem. The Philosophical Review, 104(1), 1–52.

    Article  Google Scholar 

  • DeRose, K. (2009). The case for contextualism: Knowledge, skepticism, and context (Vol. 1). Oxford: Oxford University Press.

    Book  Google Scholar 

  • Dretske, F. (2003) Externalism and self-knowledge. In S. Nuccetelli (Ed.), New essays on semantic externalism and self-knowledge (pp. 131–142). Cambridge, MA: MIT Press.

  • Falvey, K., & Owens, J. (1994). Externalism, self-knowledge, and skepticism. Philosophical Review, 103, 107–137.

  • Farkas, K. (2008). The subject’s point of view. New York: Oxford University Press.

    Book  Google Scholar 

  • Gertler, B. (2000). The mechanics of self-knowledge. Philosophical Topics, 28(2), 125–146.

    Article  Google Scholar 

  • Ginzburg, J. (1995). Resolving questions: I. Linguistics and Philosophy, 18, 459–527.

    Article  Google Scholar 

  • Ginzburg, J. (2011). How to resolve how to. In J. Bengson & M. Moffett (Eds.), Knowing how (pp. 215–243). Oxford: Oxford University Press.

    Google Scholar 

  • Goldberg, S. (1999). The relevance of discriminatory knowledge of content. Pacific Philosophical Quarterly, 80, 136–156.

    Article  Google Scholar 

  • Goldberg, S. (2003). What do you know when you know your own thoughts? In S. Nuccetelli (Ed.), New essays on externalism and self-knowledge (pp. 241–256). Cambridge, MA: MIT Press.

    Google Scholar 

  • Goldberg, S. (2006). Brown on self-knowledge and discriminability. Pacific Philosophical Quarterly, 87, 301–314.

    Article  Google Scholar 

  • Goldman, A. (1976). Discrimination and perceptual knowledge. Journal of Philosophy, 64, 355–372.

    Google Scholar 

  • Goldman, A. (1986). Epistemology and cognition. Cambridge, MA: Harvard University Press.

  • Green, M. (2005). Moorean absurdity and seeing what’s within. In M. Green & J. Williams (Eds.), Moore’s paradox: New essays on belief, rationality, and the first person (pp. 189–216). Oxford: Oxford University Press.

    Google Scholar 

  • Heal, J. (1994). Moore’s paradox: A Wittgensteinian approach. Mind, 103, 5–24.

    Article  Google Scholar 

  • Heil, J. (1988). Privileged access. Mind, 42(386), 238–251.

    Article  Google Scholar 

  • Hookway, C. (2008). Questions, epistemology, and inquiry. Grazer Philosophische Studien (knowledge and questions), 77, 1–22.

    Google Scholar 

  • Kallestrup, J. (2009). Knowledge-wh and the problem of convergent knowledge. Philosophy and Phenomenological Research, 78, 469–476.

    Article  Google Scholar 

  • Kripke, S. (Ed.). (2011). Frege’s theory of sense and reference: Some exegetical notes. Philosophical troubles: Collected papers (Vol. 1, pp. 254–291). Oxford: Oxford University Press.

  • Lewis, D. K. (1982). Whether report. In T. Pauli, et al. (Eds.), Philosophical essays dedicated to Lennart Åqvist on his fiftieth birthday (pp. 194–206). Uppsala: Filosofi ska Studier.

    Google Scholar 

  • Lewis, D. K. (1996). Elusive knowledge. Australasian Journal of Philosophy, 74(4), 549–567.

    Article  Google Scholar 

  • McGinn, C. (1977). Charity, interpretation, and belief. Journal of Philosophy, 74, 521–535.

    Article  Google Scholar 

  • McKinsey, M. (1991). Anti-individualism and privileged access. Analysis, 51, 9–16.

    Article  Google Scholar 

  • Millikan, R. (Ed.). (1993). White queen psychology; or, the last myth of the given. White queen psychology and other essays for Alice (pp. 279–364). Cambridge, MA: MIT Press.

  • Millikan, R. (2001). The myth of mental indexicals. In A. Brook & R. Devidi (Eds.), Self-reference and self-awareness: Advances in consciousness research (Vol. 11, pp. 167–181). Amsterdam: John Benjamins.

    Google Scholar 

  • Millikan, R. (2004). On clear and confused ideas. Cambridge: Cambridge University Press.

    Google Scholar 

  • Millikan, R. (2012). Are there mental indexicals and demonstratives? Philosophical Perspectives, 26, 217–234.

    Article  Google Scholar 

  • Parent, T. (2007). Infallibilism about self-knowlege. Philosophical Studies, 113, 411–424.

  • Parent, T. (2014). Knowing-wh and embedded questions. Philosophy Compass, 9, 81–95.

  • Perry, J. (1979). The problem of the essential indexical. Noûs, 13, 3–21.

    Article  Google Scholar 

  • Peacocke, C. (1996). Entitlement, self-knowledge and conceptual re-deployment. Proceedings of the Aristotelian Society, 96, 117–158.

    Google Scholar 

  • Putnam, H. (1973). Meaning and reference. Journal of Philosophy, 70(19), 699–711.

    Article  Google Scholar 

  • Putnam, H. (Ed.). (1975). The meaning of ‘meaning’. Mind, language, and reality: Philosophical papers (Vol. 2, pp. 215–271). Cambridge: Cambridge University Press.

  • Schaffer, J. (2007). Knowing the answer. Philosophy and Phenomenological Research, 75(2), 383–403.

    Article  Google Scholar 

  • Searle, J. (1983). Intentionality: An essay in the philosophy of mind. Cambridge: Cambridge University Press.

    Book  Google Scholar 

  • Stanley, J. (2011). Know how. New York: Oxford University Press.

    Book  Google Scholar 

  • Sterelny, K. (1988). Review of Knowing who by Stephen E. Boer and William G Lycan. Philosophy of Science, 55, 654–656.

  • Stich, S. (1978). Autonomous psychology and the belief-desire thesis. The Monist, 61, 573–591.

    Article  Google Scholar 

  • Warfield, T. (1992). Privileged self-knowledge and externalism are compatible. Analysis, 52(4), 232–237.

    Article  Google Scholar 

  • Wikforss, Å. (2008). Self-knowledge and knowledge of content. Canadian Journal of Philosophy, 38, 399–424.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Philosophy (0126), Virginia Tech, 220 Stanger Street, Blacksburg, VA, 24061, USA

    T. Parent

Authors
  1. T. Parent
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to T. Parent.

Appendix

Appendix

The semantics and metaphysics concerning “knowing-wh” is receiving more attention than ever these days. Because of that, I wish to spell out in a bit more detail the purpose-relative semantics, and what it says about Descartes and his “knowing what” he thinks. Further details on such a semantics are also found in Boer and Lycan (1986); I refer the reader to their impressive discussion Chaps. 1 and 2.

A “purpose” is a state of successful action, such as “fetching water” or “answering (Q).” Assume, then, that S is a subject, \(\upmu \) is a variable, \(\uppsi \) is a name, demonstrative, or definite description. And suppose that \(\Phi \) is an “important predicate” for purposes P (cf. Boer and Lycan, pp. 34–35). Then given a \(\uppsi \), define the (possibly empty) set \(K_S^t\) of predicates that S satisfies at time \(t\), where each predicate has the normal form \(^{\ulcorner }\upmu \) knows-true that \(\Phi (\uppsi )^{\urcorner }\).Footnote 23 The conditions on “knowing what” are then roughly as follows:

(KW):

S satisfies \(^{\ulcorner }\upmu \) knows what \(\uppsi \) is\({}^{\urcorner }\) at \(t\) for the purpose of P iff: \(K_S^t\) requires no further predicates for an abilityFootnote 24 in S to achieve P at \(t\).

More intuitively, S knows-what iff she has enough knowledge-that about the denotation of \(\uppsi \) for an ability to achieve P. Substitutions for ‘P’ here might include ‘fetching a glass of water,’ ‘answering correctly the question on the chemistry exam’, ‘answering (Q)’, and so on. Whereas, important predicates might include ‘is \(\hbox {H}_{2}\hbox {O}\)’, ‘is that’ [attended by a suitable ostension], ‘is possibly a liquid in lakes and rivers’, etc.

Thus, if \(\uppsi \) is replaced by ‘water’, ‘P’ is replaced with ‘fetching a glass of water’ and \(K_S^t\) = {‘\(x\) knows-true that water flows out of taps’}, then (KW) implies that at \(t\):

(KW1):

S knows what water is for the purpose of fetching a glass of water iff: \(K_S^t\) requires no predicate beyond ‘\(x\) knows-true that water flows out of taps’ for an ability in S to achieve fetching a glass of water at \(t\).

Less formally, S knows what water is for this purpose iff her knowing that water flows out of taps is all she needs to know to fetch a glass of water. Or better, it is all the knowledge-that needed about water.

Note that (KW1) does not require S to actually possess the ability. A differently-abled person can “know what” just as much as anyone else. The idea is rather that S “knows what” if the relevant ability does not demand any further knowledge-that about water, beyond what S already has. Naturally, the ability might require other things as well. But as long as she has the requisite knowledge-that, she then counts as “knowing what,” even if other requisites for the ability are absent.

What of Descartes’ “knowing what” he thinks? Where ‘x’ is a variable for an essential indexical (see n. 4), suppose S = Descartes and \(K_S^t\) ={‘\(x\) knows-true that water is a possible, colorless, odorless liquid in lakes and rivers’, ‘\(x\) knows-true that x is thinking forthwith that water is wet’, ‘\(x\) knows-true it is certain that x is thinking forthwith that water is wet’}. Then, (KW) implies that:

\((\hbox {KW}_\mathrm{D})\) :

Descartes satisfies \(^{\ulcorner }\upmu \) knows what \(\underline{\upmu }\) thinks\({}^{\urcorner }\) at \(t\) for the purpose of answering (Q2) affirmatively iff: for an ability in Descartes to answer (Q2) affirmatively, \(K_S^t\) requires no predicates beyond ‘\(x\) knows-true that water is a possible, colorless, odorless liquid in lakes and rivers’, ‘\(x\) knows-true that x is thinking forthwith that water is wet’, and ‘\(x\) knows-true it is certain that x is thinking forthwith that water is wet’.

Furthermore, the Reflective Awareness View will suggest that:

\((\hbox {RA}_\mathrm{D})\) :

Descartes satisfies at \(t\) ‘\(x\) knows-true that x is thinking forthwith that water is wet’ and ‘\(x\) knows-true it is certain that x is thinking forthwith that water is wet’ if Descartes judges (SV) at \(t\) in conditions (a)–(c).

Thus, if Descartes judges (SV) while introspecting on the judgment so as to meet (a)–(c), the Reflective Awareness View implies that (with the right background knowledge) Descartes indeed “knows what” he thinks, for the purposes of answering (Q2) affirmatively. Footnote 25

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Parent, T. Externalism and “knowing what” one thinks. Synthese 192, 1337–1350 (2015). https://doi.org/10.1007/s11229-014-0624-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11229-014-0624-x

Keywords

Search

Navigation