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Subject-Sensitive Invariantism and Isolated Secondhand Knowledge


Jennifer Lackey challenges the sufficiency version of the knowledge-action principle, viz., that knowledge that p is sufficient to rationally act on p, by proposing a set of alleged counterexamples. Her aim is not only to attack the knowledge-action principle, but also to undermine an argument for subject-sensitive invariantism. Lackey holds that her examples are counterexamples to the sufficiency version of the knowledge-action principle because (a) S knows the proposition in question, but (b) it is not rational for S to act on it. In this paper, first, I argue against (a) on intuitive and on theoretical grounds. Second, I point out that (b), even if combined with (a), is not sufficient to make for counterexamples to the knowledge-action principle of the relevant kind. Third, I offer two alternative explanations of the intuition Lackey relies on. If either one of them is right, (b) may not be satisfied in her examples.

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  1. 1.

    There is more than one argument for SSI. Many regard the argument from the knowledge-action principle as the main one.

  2. 2.

    Lackey (2011), in much the same way, challenges the sufficiency version of the knowledge norm of assertion—the principle that states, roughly, that if S knows that p, then it is permissible for S to assert that p. Some of my arguments against Lackey’s alleged counterexamples to the knowledge-action principle, mutatis mutandis, work against those to the knowledge norm of assertion, but my main focus here is on the knowledge-action principle. Note that the knowledge-action principle and the knowledge norm of assertion are different principles, and usually need to be defended or objected to on different grounds. I agree with Brown (2012a) that they bear no straightforward relation to each other.

  3. 3.

    If anti-Gettiering conditions are not responsible for the strength of S’s epistemic position, it can be added (iv) that S is not Gettiered. Adding (iv) will make the relations between different senses of ‘epistemic’ discussed below more complex.

  4. 4.

    Stanley (2005, pp. 1–3) attributes this thrust to purism.

  5. 5.

    A way to maintain both the knowledge-action principle and purism about knowledge is to espouse infallibilism about knowledge. Infallibilism about knowledge arguably entails global skepticism, viz., that the epistemic standard is always that relative to which, for any S and p, S’s epistemic position regarding p is too weak to be good enough for knowledge. The knowledge-action principle, then, is trivially true because its antecedent is false. For more on the relation between SSI and skepticism, see Fantl and McGrath (2009).

  6. 6.

    On Fantl and McGrath’s definition, p being warranted enough to justify means that the weakness of S’s epistemic position with regard to p does not prevent p from being a justifier. It is, then, possible that p, even if warranted enough to justify φ-ing, fails to be a justifier for it, e.g., because p has no inferential relation to φ-ing (I discuss this point in more detail in Section 5). Throughout the paper, I follow this definition and apply it to other similar locutions, such as ‘warrant or epistemic position is strong enough.’

  7. 7.

    Although the knowledge-action principle, whether SSI-friendly or not, is formulated differently, and their differences are not marginal, I ignore most of them in much of the paper. This is because Lackey’s aim is not to attack the details of particular formulations of the knowledge-action principle. The only difference that is crucial for my purposes is between SSI-friendly formulations and others. I aim to defend the former from Lackey’s alleged counterexamples. Ichikawa (2012) defends the latter from many alleged counterexamples including Lackey’s. Ichikawa’s point is not incompatible with mine. Although he does not put his point this way, his main idea can be easily modified as follows: Lackey’s and others’ putative counterexamples to the knowledge-action principle are consistent with the possibility that S’s epistemic position regarding p is strong enough for S to justify or rationalize the action S does, but the degree of justification or rationalization p confers on the action is weak. This possibility remains because p may not be a good enough reason to justify or rationalize S’s particular action. I pursue a different line of response, since the relevant propositions in the putative counterexamples seem to be good enough reasons for what S does therein; though I agree with Ichikawa that to settle what interpretation of the examples is correct, there needs to be a principle determining what counts as good reason for what. I thank Jonathan Jenkins Ichikawa for helpful discussion.

  8. 8.

    Lackey seems to assume that the inductive strength of the evidence S has for the reliability of the source of isolated secondhand information p determines S’s epistemic position regarding p. This is perhaps why she holds that when Eliza knows that Anna is extremely reliable, Eliza is in a nearly perfect epistemic position with regard to Anna’s diagnosis. One may object to this assumption for the following reason: S’s epistemic position is significantly improved if S gains independent evidence for p, and discharges the isolated status of p, even when S has nearly perfect inductive evidence for the reliability of the information source. This may suggest that inductive evidence, however good, may not put S in a very strong epistemic position.

  9. 9.

    As a matter of fact, my intuitions about Lackey’s examples significantly vary in terms of content and strength. For some examples, I have strong intuitions that S knows and that it is appropriate for S to act. For ONCOLOGIST, my intuition is that Eliza knows but her action is somehow inappropriate. In Section 6, I attempt to articulate the sense of ‘somehow’ involved in my intuition.

  10. 10.

    MacFarlane (2005) argues that non-reductionism about testimonial knowledge, as it stands, is inconsistent with the knowledge-action principle for a principled reason: non-reductionism does not take account of interpersonal differences in stakes. Unless some further argument is given, it is an open question whether the knowledge-action principle or non-reductionism is to be modified. Lackey’s examples, even if granted to be legitimate, just extend this question so as to apply to reductionism as well. I argue below that the knowledge-action principle is theoretically more secure than Lackey claims it is.

  11. 11.

    Fantl and McGrath formulate the unity thesis in terms of a reason to believe rather than justification or rationality: “If p is warranted enough to be a reason you have to believe that q, for any q, then p is warranted enough to be a reason you have to φ, for any φ” (Fantl and McGrath 2009, p. 73). Again, details of the thesis do not matter much here. Hawthorne and Stanley (2008, p. 577) allude to, but do not argue for, the unity thesis.

  12. 12.

    Note that the results of the ultrasound and MRI were positive is not a reason for which Eliza believes that Lucas has pancreatic cancer. Rather, she has inferred the former from the latter.

  13. 13.

    My arguments in this section are modeled on Fantl and McGrath’s (2009) arguments against some alleged counterexamples to their knowledge-action principle, including one offered by Brown (2008). To counter the argument from the unity thesis, however, Brown (2012b) argues that her counterexample indeed goes against the unity thesis as well. I am convinced by Fantl and McGrath’s (2012a, 2012b) responses to Brown, and take it to be safe to assume the unity thesis.

  14. 14.

    This is one of the points Lackey makes in response to the objection that the intuitive inappropriateness in her examples is merely social rather than epistemic.

  15. 15.

    Fantl and McGrath, in their (2007), defend (3) entailing (4) by arguing that the conversational implicature from (3) to (4) is not cancelable.

  16. 16.

    Lackey holds that by closure, Eliza knows and hence rationally or justifiably believes that scheduling or administering a highly aggressive combination of radiation and chemotherapy for Lucas is the thing to do, whereas she is not rational or justified in doing the thing to do. As I argued in Section 4, unless more arguments are given, it is not easy to sever the link between theoretical and practical rationality.

  17. 17.

    Sher (2009) examines various analyses of ‘you should know’ involved in an agent’s responsibility for her wrong-doing. He refuses the analysis that merely situational factors constitute the relevant sense of epistemic responsibility, on the ground that it makes epistemic responsibility too foreign to the agent’s epistemic abilities to render it worth calling ‘epistemic’. Sher’s own analysis implies that the agent should know her wrongness or foolishness if her failure to recognize evidence for her wrong or foolish action (a) “falls below some applicable standard” and (b) “is caused by the interaction of some combination of his constitutive attitudes, dispositions, and traits” (ibid., p. 88). These conditions may not be applicable to some of Lackey’s examples. Notwithstanding the theoretical difficulty of factoring out precise conditions for epistemic responsibility, it is enough for my purposes here that there is some intuitive sense of ‘S should know the norm’ in the relevant examples in which S doesn’t know it; I only intend to give an account of what is behind our intuition of L-epistemic inappropriateness. It is not surprising if some of our intuitions conflict with a well-grounded account in the final analysis.

  18. 18.

    The epistemic irresponsibility for action I am suggesting may carry over to the epistemic irresponsibility for belief via a variant of the unity thesis. This is indeed how Van Woudenberg (2009) argues for epistemic responsibility for belief, oblivion, and ignorance. Van Woudenberg’s notion of epistemic responsibility for belief is a far cry from the notion so called in the traditional epistemological literature, and there is no way to make the former a necessary condition for knowledge. For this reason, even if the unity thesis about epistemic responsibility in his or my sense is correct, it does not imply that S does not know p when S’s acting on p is epistemically irresponsible in this sense. Kornblith (1983) tries to defend epistemic responsibility in the traditional sense as a necessary condition for knowledge by making use of a variant of the unity thesis.

  19. 19.

    When I wrote this paper, I lived in Canada, where Federal Motor Vehicle Safety Standard 108 requires that all vehicles made since 1 January 1990 turn on lights even in the daytime.

  20. 20.

    For these issues, see, e.g., Grimm (2006), Kvanvig (2003), and Zagzebski (2001, 2009). Zagzebski’s view on understanding as a whole may be controversial, but all I need to run the argument below is that understanding has essential features that are missing in Lackey’s examples, and the absence of such features is explanatory of L-epistemic inappropriateness. I believe that any available view on understanding can satisfy these conditions, but I pick Zagzebski’s because only she explicitly mentions how understanding is (not) related to testimony.

  21. 21.

    Hills (2009, 2010) holds, roughly, that moral beliefs lead to morally worthy action only if they are held on the basis of moral understanding, and that moral beliefs are not rational unless they are held on the basis of moral understanding. Some might argue from here that subjects in Zagzebski’s examples are not rational to believe or act on the proposition in question, and so her cases are counterexamples to the knowledge-action principle after all. What Hill means by ‘epistemic rationality,’ however, is much broader than the sense of rationality that matters in the knowledge-action principle (see Hill 2010, pp. 223–30). So Hill’s position does not exclude the point I’m making here, that the knowledge-action principle is compatible with epistemic inappropriateness of action in a broad sense. I thank Jennifer Lackey for suggesting comparing my view with Hill’s.

  22. 22.

    The same kind of diagnosis of Lackey’s examples as offered here, that L-epistemic inappropriateness is better explained by lack of understanding, is also offered by Carter and Gordon (2011), though their focus is on the knowledge norm of assertion attacked by Lackey (2011). They argue that the kind of understanding S lacks in Lackey’s examples is “atomistic understanding” of why p is evaluated as being as it is. Beyond what I claim here, I don’t commit myself to any substantive thesis about understanding in general and the kind of understanding relevant to Lackey’s examples in particular. Carter and Gordon claim that Lackey succeeds at denying what they call the “quantitative view,” assumed by many proponents of the knowledge norm of assertion: “The question “What is the norm of assertion?” is best answered by determining how much epistemic support is required to warrant assertion” (Carter and Gordon 2011, p. 619). What they mean by ‘quantity of support’ is close to epistemic in the sense of being truth-conducive or error-averse. The quantity view is denied because, they argue, Lackey’s examples suggest that at least in some cases, understanding rather than knowledge is the norm of assertion. As they are aware, whether the denial of the quantitative view entails the denial of the knowledge norm of assertion depends on what sense of propriety or appropriateness of assertion is relevant to the knowledge norm of assertion. The SSI-friendly version of the knowledge-action principle does not involve this kind of ambiguity, since the relevant sense is determined to be quantitative, as Carter and Gordon use the term. For this reason, the SSI-friendly version of the knowledge-action principle is compatible with the claim that epistemically appropriate action in this sense is not L-epistemically appropriate due to S’s lack of understanding.

  23. 23.

    This does not mean that Lackey’s examples are not interesting for any epistemological reason. Epistemology covers other cognitive states than knowledge. I have no doubt that L-epistemic appropriateness provides fuel for further epistemological theorizing.


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I thank Roger Clarke, Jeremy Fantl, and Carrie Ichikawa Jenkins for helpful discussions and comments on earlier drafts of the paper. A short version of the paper was presented at the 34th International Wittgenstein Symposium. I appreciate discussions there, especially with Jennifer Lackey.

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Correspondence to Masashi Kasaki.

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Kasaki, M. Subject-Sensitive Invariantism and Isolated Secondhand Knowledge. Acta Anal 29, 83–98 (2014).

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  • Subject-Sensitive Invariantism
  • Knowledge-Action Principle
  • Isolated Secondhand Knowledge
  • Testimonial Knowledge
  • Jennifer Lackey