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Assertion, practical reasoning, and epistemic separabilism


I argue here for a view I call epistemic separabilism (ES), which states that there are two different ways we can be evaluated epistemically when we assert a proposition or treat a proposition as a reason for acting: one in terms of whether we have adhered to or violated the relevant epistemic norm, and another in terms of how epistemically well-positioned we are towards the fact that we have either adhered to or violated said norm. ES has been appealed to most prominently in order to explain why epistemic evaluations that conflict with the knowledge norm of assertion and practical reasoning nevertheless seem correct. Opponents of such a view are committed to what I call epistemic monism (EM), which states that there is only one way we can be properly evaluated as epistemically appropriate asserters and practical reasoners, namely in terms of whether we have adhered to or violated the relevant norm. Accepting ES over EM has two significant consequences: first, a “metaepistemological” consequence that the structure of normative epistemic evaluations parallels that found in other normative areas (namely, moral evaluations), and second, that the knowledge norms of assertion and practical reasoning are no worse off than any alternatives in terms of either explanatory power or simplicity.

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  1. I take Gettiered to encompass traditional Gettier cases as well as other kinds of justified true beliefs that fall short of knowledge, such as barn facade cases and their kin (see Goldman 1976). Gettiered is named after Edmund Gettier’s famous (1963).

  2. As opposed to the other authors considered here, DeRose is a contextualist, i.e. a proponent of the view that the semantic value of a knowledge ascription depends on the context of the ascriber. Contextualism, I think, does not have any better way of handling the JFB and Gettiered cases when it comes to a contextualist-knowledge norm of assertion or practical reasoning: one can still have a justified but false belief in a context, and assert the content of that belief in that context, thus violating the knowledge norm but still seemingly doing something epistemically appropriate. Similarly, I mentioned Fantl and McGrath (2002, 2009) as proponents of a knowledge norm of practical reasoning. Fantl and McGrath are proponents of interest-relative invariantism (IRI), i.e. the view that whether one has knowledge that p depends at least in part on practical factors surrounding the truth or falsity of p. Again, the proponent of IRI is going to face problems like JFB and Gettiered, since one might be justified in believing a proposition which happens to be false in a situation in which there are no relevant stakes standing in the way of one knowing that p.

  3. Here I am discussing norms of assertion and practical reasoning, but one might wonder whether we should also add norms of belief to the discussion, since debates concerning the correct norm of belief has faced similar issues in determining the epistemic conditions for its proper formation. I leave out beliefs here for two reasons: first, the literature on the norms of belief is too extensive to do proper justice to in this space. Second, it is not clear to me whether the discussion of the norms of belief are really that similar to those of assertion and practical reasoning. Specifically, assertions and practical reasoning both involve action (in that assertions are actions and that practical reasoning is directed towards action) in a way that, arguably, forming a belief does not (in that a belief is not an action, nor is it necessarily directed towards action). This is not, however, to say that epistemic separabilism is necessarily concerned solely with norms that somehow involve actions; whether this difference between assertions, instances of practical reasoning and beliefs does, in fact, say anything important about the underlying epistemic issues is not an issue I can deal with adequately here.

  4. Other similar situations are ubiquitous in sports: a soccer player might illegally stop an otherwise sure goal with his or her hands in order to risk the consequences of a penalty shot; better a slim chance at preventing a goal than a guaranteed goal against (infamously, such a manoeuvre was attempted—successfully—in the 2010 World Cup, for example). Similar situations occur in hockey and, I am sure, in many other sports that I am less familiar with.

  5. Talk of the “goal” of proper ϕ’ing should not be taken to imply that the norm of assertion is only applicable inasmuch as we desire to assert appropriately, i.e. that in those cases in which I want to assert properly, I should meet certain epistemic conditions. Rather, our assertions are proper or improper regardless of what our goals are: we are subject to evaluation as epistemic subjects just be asserting.

  6. Thanks to an anonymous referee for pushing me on this question.

  7. For an extensive treatise on the epistemic conditions that determine moral culpability, see Sher (2009). The other component of moral culpability is often taken to be that the act was performed “freely”, or as a function of the agent’s “agency”. See, however, Arpaly (2003) for a dissenting view.

  8. Indeed, Weiner appeals explicitly to such a normative structure to explain how the truth norm can accommodate our intuitions of cases like JFB (2005, p. 243).

  9. A choice situation is “p-dependent” just in case one’s preferred choice given that p is true differs from one’s preferred choice given that p is false. The p-dependency condition is included to make sure that only the propriety of acting on propositions that are relevant given one’s situation are under the jurisdiction of the JBK-Reasons norm (see also Fantl and McGrath 2002; Stanley and Hawthorne 2008).

  10. Similar concerns apply to a norm that states that one’s assertion or treatment of a proposition p for a reason for acting is epistemically appropriate when one believes that one knows that p, or in which one otherwise takes oneself to be in a position such that one knows that p, etc. Specifically, if such a view requires that one has actually formed a belief that one knows that p, then this norm is going to rule out all of those cases in which one simply didn’t happen to form the relevant belief. Having actually formed the belief that “I know that p”, however, neither seems like something we typically do, nor does it seem relevant to the propriety of our assertions or actions. If the norm requires that we would be merely disposed to form such a belief then we will again be able to have good reason to think we are adhering to such a norm when we are actually violating it. For additional concerns concerning the plausibility of this kind of rule, see (Williamson 2000, pp. 260–262).

  11. For example, we might think that what is rationally credible for me is a function of the total evidence that I have. If I can have good reason to think that my evidence is different than it actually is, then I can be mistaken about what is rationally credible for me.


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Boyd, K. Assertion, practical reasoning, and epistemic separabilism. Philos Stud 172, 1907–1927 (2015).

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  • Assertion
  • Practical reasoning
  • Norms
  • Knowledge