Doxastic Ordering Sources

First, we need to understand how ‘should’ comes to express epistemic normativity. The general idea that I suggest is straightforward: on Kratzer’s semantics for ‘must’, the flavour of modality that ‘must’ carries is partly determined by the ordering source that is provided by the context in which ‘must’ occurs. ‘S must doA’ occurring at c means that morality demands thatS doesA if the ordering source provided by c ranks worlds according to whether S acts in accordance with moral norms. Similarly, ‘S must believe P’ occurring at cmeans that S is epistemically required to believe P ifc provides an ordering source that ranks worlds according to whetherS’s doxastic attitudes satisfy epistemic norms. In the introduction I have characterized epistemic norms as being about what one should believe in light of considerations pertaining to truth, knowledge, justification, evidence, cognitive reliability, and the like. For example, a doxastic ordering source could be such that it contains all and only worlds where the relevant subject

S believes all and only true propositions. This ordering source would reflect the truth norm according to which one should believe a propositionP iff P. In the following, I will refer to any ordering sources that reflects an epistemic norm as

It depends on the particulars of your favourite semantics for the deontic ‘should’ how the story about how the doxastic ‘must’ expresses epistemic normativity carries over to the doxastic ‘should’. The options mentioned in section 2.4 were:

• Two ordering sources (von Fintel and Iatridou ms, 2008): ‘S should do A’ is true at a contextc iffS doesA in all thoseg(w)-best worlds in the modal background ∩f(w) that are ranked best by the secondary ordering sourceh, wheref,g, and h are provided byc.

• Conditional strong necessity modals (Silk 2012): ‘S should doA’ is true at a context iff ‘If specific conditionC obtains, S must doA’ is true atc.

• Most-quantifier (Finlay 2014, forthcoming): ‘S should do A’ is true at a context c iff S does A in most worlds in the modal background ∩f(w) updated by the goal z, wheref andz are provided by c.

All these can be used as semantic models for the doxastic ‘should’. I suggest that on von Fintel and Iatridou (ms, 2008)’s account, ‘S should do A’ uttered at a contextc expresses epistemic normativity if the two ordering sourcesg and

h provided byc rank worlds according to epistemic norms. This assumes that there are two different kinds of epistemic norms, more coercive ones, that are reflected by the primary ordering source, and less coercive ones, reflected by the secondary ordering source. If there is no such distinction among epistemic norms, then von Fintel and Iatridou’s (2008) account leaves two options. First, one could conclude that there is no real distinction between the doxastic ‘should’ and ‘must’ and that they basically mean the same. A second, alternative option is to say that the doxastic ‘should’ is not a deontic, but another kind of modal. Von Fintel and Iatridou don’t agree on whether the non-epistemic ‘should’ is a deontic modal anyway (von Fintel and Iatridou 2008: 128). One of them suggests that it is rather a teleological modal. If we apply this interpretation to the doxastic ‘should’, we have an alternative account of under which conditions ‘should’ expresses epistemic normativity: when the ordering sources rank worlds according to whether the subject’s doxastic attitudes in those worlds are what they need to be like in order for the subject to achieve a certain epistemic goal, e.g., true belief or knowledge. The primary ordering source simply ranks all those worlds best in which this epistemic goal is achieved. The secondary ordering

source ranks all those worlds best in which the goal is achieved in the best manner. There might be no conceivable notion of achieving an epistemic goal in a better or worse manner, in which case we would end up, again, with the conclusion that there is no distinction between what one, doxastically, should and what one, doxastically, must believe.

On Finlay’s account, the update of the modal background by a goalzeffectively works as a ranking of the worlds in the modal background by an ordering source which ranks worlds in light of whether z is achieved in these worlds. ‘Should’ is doxastic on such an account if the contextually salient goal is an epistemic goal, similar to the view suggested by the second possible reading of von Fintel and Iatridou (ms, 2008),

Finally, on Silk’s account of ‘should’ as a conditional strong necessity modal, ‘should’ is doxastic if the ordering source determining the modal flavour of the ‘must’ that occurs in the consequent of the conditional stating the truth-conditions

for should-sentences is doxastic.

If we ignore the details of the specific accounts, what remains is that ‘should’ is doxastic if the ordering source(s) or goal supplied by the context in which it is uttered reflect(s) an epistemic norm or norms. I want to stay neutral on what these epistemic norms are. I will suggest some candidates in section 2.7, but the simplistic semantics for the doxastic ‘should’ that I will present there is purposively designed such that it’s flexible enough to accommodate as many different epistemic norms as possible. In the spirit of Carr’s remark that it is not the job of semantics to settle normative debates, it seems wrong to build a certain kind of epistemic norm into the semantics for the doxastic ‘should’.

Before moving on to the issue of information-sensitivity, let me shortly address a question that might have come up in this subsection. As von Fintel and Iatridou’s (2008) and also Finlay’s (2014, forthcoming) discussion of ‘should’ suggest, we could classify the doxastic ‘should’ as ateleological rather than adeontic modal. If it is a teleological modal, it expresses which doxastic attitude one has to adopt in order to achieve an epistemic goal or telos, for example to believe only true propositions or only propositions one knows. Two remarks. First, I’m hesitant to categorize the doxastic ‘should’ as a teleological modal since this would amount to the claim that it is a semantic truth that epistemic instrumentalism is correct. This is the view that epistemic norms are instrumental norms, which tell us what

the means are to achieve certain epistemic ends. As this view is very controversial in epistemology,20 I think we should reject, again in the spirit of Carr’s (2015) objection to Cariani (2013) and Charlow (2013), a semantics that would commit us to a particular view on this issue. If we consider the doxastic ‘should’ to be deontic we leave this open, since the rules expressed by deontic modals can be either instrumental or not. Second, it does not matter too much for the purposes of this PhD thesis whether the doxastic ‘should’ is deontic or teleological. What matters is whether it is information-sensitive, and it can be information-sensitive as a teleological modal just as well as it can be as a deontic modal. We can relativize what should be done in order to achieve a goal z to different sets of evidence. What one should do in order to achieve the goal of saving as many miners as possible in light of ignorance about where the miners are differs from what one should do for this purpose in light of knowing that they are in shaft 1.