© LOGOS & EPISTEME, VI, 3 (2015): 367-370 ON HAVING EVIDENCE: A REPLY TO NETA Arturs LOGINS ABSTRACT: According to one line of thought only propositions can be part of one's evidence, since only propositions can serve the central functions of our ordinary concept of evidence. Ram Neta has challenged this argument. In this paper I respond to Neta's challenge. KEYWORDS: evidence, Ram Neta, Timothy Williamson, propositions, central function of evidence argument According to one influential line of thought only propositions can be part of one's evidence, since only propositions can serve the central functions of our ordinary concept of evidence. Namely, only propositions can serve functions of inference to the best explanation, figuring in probabilistic confirmation and ruling out of hypotheses.1 Consider inferences to the best explanation. You cannot explain cucumber. You can explain why cucumbers have this or that particular feature, why they are green, why they are classified as accessory fruits, why you like/hate cucumbers, etc. A sentence of the form "Cucumber because ..." is ungrammatical. 'Because' can grammatically conjoin only declarative sentences. Hence, the argument goes, only propositions can figure in inferences to the best explanation. Similar considerations apply to the probabilistic confirmation/reasoning and the ruling out of hypotheses. The central function argument for the propositionality of evidence has been recently criticized. One particularly puzzling challenge consists in questioning the assumed understanding of explanation, probabilistic reasoning and exclusion of hypotheses. The thought is that, contrary to what a proponent of the central function argument suggests, it need not be the case that only propositions can be the relata of inference to the best explanation, probabilistic reasoning, and the ruling out of hypotheses. This line of objection has been recently considered by Ram Neta.2 In what follows I reply to Neta's objection. 1 Cf. Timothy Williamson, Knowledge and its Limits (Oxford: Oxford University Press, 2000), 194-200. 2 In Ram Neta, "What Evidence Do You Have?" British Journal for the Philosophy of Science 59 (2008): 89–119. Arturs Logins 368 With respect to the considerations about inferences to the best explanation Neta suggests more specifically: [E]ven if the conjunction 'because' can grammatically conjoin nothing other than declarative sentences, nothing about the relata of why-explanations follows from this feature of the conjunction. Might this not be a case in which grammar is metaphysically misleading? 3,4 Neta seems to suggest in this passage that considerations about language use don't entail one or another view about the relata of why-explanations. This much seems to be true, indeed. However, that facts about our language use don't entail any particular view about why-explanations, doesn't mean that they provide no support whatsoever for one or another view. Moreover, Neta's own argumentative dialectic relies on the thought that facts about the way we speak might support a philosophical view about evidence. Neta proposes, for instance, various examples that, allegedly, support the view that non-propositional items can play a role in explanations and probabilistic reasoning. Neta claims that the ordinary talk of bloody knives as evidence, of clouds being evidence that it will rain and people "planting evidence" suggests that the grammar of 'because,' as it is assumed in the argument from the central functions of evidence is metaphysically misleading.5 That is, according to Neta, given the way we ordinarily talk about evidence (in particular by treating objects as evidence) we can infer that the relata of why-explanations need not be propositional. This line of thought doesn't challenge the view that figuring in inferences to the best explanation is a central role of evidence. It accepts that it is a central role of evidence. Rather, the thought is that given facts about our ordinary language use (in particular the talk of bloody knives as evidence) and the fact that 3 Neta, "What Evidence Do You Have?" 96. 4 Neta's treatment of considerations from probabilistic reasoning and ruling out of hypotheses is similar to his treatment of considerations about inferences to the best explanation. See for instance: "Why should we accept the claim that, 'when "probability" has to do with the evidential status of beliefs,' then 'what has a probability is a proposition'? Why not say instead that what has a probability is, at least in some cases, an event or a state rather than a proposition? What is the probability of the knife's being (in the state of being) bloody, given that the defendant is guilty?" (Neta, "What Evidence Do You Have?" 97). And: "Let's grant that only propositions can be inconsistent in the relevant sense. Why should we allow, though, that there is an inconsistency between hypothesis and evidence itself, rather than an inconsistency between hypothesis and one or another statement of the evidence?" (Neta, "What Evidence Do You Have?" 97). Hence, I propose to focus here on his reply to the considerations about inference to the best explanation. 5 Cf. Neta, "What Evidence Do You Have?" 96. On Having Evidence: A Reply to Neta 369 figuring in inferences to the best explanation is a central role of the ordinary concept of evidence, one is not more warranted in concluding that only propositional items can serve central functions of evidence than one is warranted in concluding that non-propositional items can figure in inferences to the best explanation. Nevertheless, Neta acknowledges that a proponent of the central function argument for propositionality of evidence might tell a story about cases where one appeals to a bloody knife as evidence. Such a story would supposedly explain what is going on in such cases by an appeal to propositions rather than by a reference to objects. Namely, Neta recognizes: Of course, it could still be that, when we speak of the bloody knife as being evidence that the defendant is guilty, what that amounts to is that there is some proposition that somehow involves reference to the bloody knife, and that is itself evidence that the defendant is guilty.6 However, according to Neta, there is a problem for the proponent of the central function argument for the propositionality of evidence if he endorses this kind of explanation. Neta claims: But if Williamson is willing to defy grammatical appearances in our account of what it is for the bloody knife to be evidence that the defendant is guilty, then why should we not be equally willing to defy grammatical appearances when it comes to why-explanations? The considerations adduced up to now seem to leave it an open question whether the explanantia of our hypotheses are propositional, and so whether evidence is propositional.7 However, these remarks are puzzling. The problem with Neta's argument is that where his opponent has proposed an error theory for cases where we say things like "The bloody knife is evidence," Neta has not proposed an alternative explanation of language facts that seam to speak against his proposal (e.g. that 'because' can conjoin only declarative sentences). He has only said that we might defy "grammatical appearances when it comes to why-explanation." One would like to know more about this suggestion before endorsing it. Why does it appear to us wrongly that only propositions can be the relata of 'because'? How exactly might we defy grammatical appearances in the case of why-explanation? In absence of a viable error theory that could reply to such questions, Neta's considerations are ad hoc. Suggesting merely that there might be an error theory that would enable us to defy grammatical appearances of why-explanations is not enough. Claiming this without a further theoretical motivation is fallacious. 6 Neta, "What Evidence Do You Have?" 96. 7 Neta, "What Evidence Do You Have?" 96-97. Arturs Logins 370 Hence, I conclude that Neta's argument fails to undermine the argument for the propositionality of evidence from the central roles of the ordinary concept of evidence.8 8 Thanks to Pascal Engel, Robin McKenna, and Tim Williamson for comments and discussion on earlier versions of the present note. The research work that lead to this article was supported by the Swiss National Science Foundation grant number 148553 (project "Evidence and Epistemic Justification") and grant number 161761 (project "Justification, Lotteries, and Permissibility").