General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms KNA: It is permissible to assert that p, only if one knows that p. 1 This norm says that an agent's assertion is permissible only if she knows what she says. If a speaker says that something which is false, unjustified or not known, then there is something inappropriate about that assertion. Crucially, KNA makes a claim about epistemic permission: an ignorant or false assertion can still be morally or prudentially 1 The knowledge-norm of assertion is formulated in several different ways: as an imperative or must claim (Williamson 2000: 241-3), as a claim about appropriateness (Brown 2008a), or as a claim about permissibility (Turri 2011: 37). There is also debate about whether the norm should also encompass the sufficiency claim (Brown 2008a(Brown , 2008b(Brown , 2010(Brown , 2012). I will not consider these issues since the counterexamples to the knowledge-norm of showing concern the necessity of know-how for appropriate showing, and will cause problems to any of these formulations.2 permissible, and a knowledgeable assertion can still be morally or prudentially impermissible. 2 Buckwalter and Turri (henceforth B&T) have recently opened up a parallel question about the epistemic permissibility of showing, claiming that 'just as knowledgethat is the norm of telling, so knowledge-how is the norm of showing ' (2014: 17). This is an important proposal, which if correct would offer insight into the normative significance of knowledge-how, deepen and widen the debate about epistemic norms, and give us a picture of the commonalities between knowledge-how and knowledge-that.Although they don't offer a formulation of this norm, the parallel norm to KNA would be a knowledge-how norm of showing, which we'll call KNS for short: KNS: It is permissible to show someone how to V, only if one knows how to V. intentional showing. In a case in which A secretly watches B make a tomato rose without B's knowledge we can say that B showed A how to make a tomato rose (Hawley 2010: 402), but I take it that this is not the sense of 'showing' that figures in KNS. 4 Moreover, KNS only concerns showing-how, and not the kind of activity that is involved in showing 2 From this point on, I will use unqualified claims about permissibility to refer to epistemic permission. 3 Although KNS is only significant if it is possible to show without having know-how. This is a point we will return to in §3.3. 4 The fact that I focus on cases in which one person learns from another's teaching should not distract us from the fact that we can also acquire know-how through imitation, practice, and simple trial and error. Since our focus will be on the norms on interpersonal teaching, giving a full account of the ways in which we can acquire know-how is beyond the scope of this paper. Thanks to an anonymous reviewer for rai...