Might generics Brian Rabern * University of Edinburgh DOI: http://dx.doi.org/10.7358/snip-2020-039-rabe The logical form of a generic sentence such as Dogs bark is usually analyzed, à la Lewis 1975, in terms of an (unpronounced) two place operator GEN and its arguments, the restrictor dogs(x) and the matrix bark(x): GEN x[dogs(x)][bark(x)]. (Our focus here is on simple characterizing generic sentences with bare plurals and stative predicates.) See Carlson and Pelletier 1995 for an overview of this standard tripartite analysis, and discussion of various complications. The semantics of GEN is more controversial. But a promising approach assigns a generic sentence the truth-conditions of a quantified modal conditional, ∀x(dogs(x) > bark(x)), where the modality is "normalcy" and > is a variably strict conditional. See Delgrande 1987, Asher and Morreau 1995, and Pelletier and Asher 1997. But how do generics interact with other modals? I'll offer one observation about an interaction with might that presents a challenge for standard theories. Wild mushrooms are a mixed bag - some are poisonous and some are harmless. So it is not the case that if something is a wild mushroom then normally it is poisonous, but it is also not true that if something is a wild mushroom then normally it isn't poisonous. There is no generic truth here. Thus, the following are both false: (1) Wild mushrooms are poisonous. (2) Wild mushrooms aren't poisonous. Of course, there are tricky cases with striking property or existential readings (Cohen 2004), but the standard analysis predicts that there are pairs such as (1) and (2) that - in the right context with the right disambiguation - are both false. Now consider the following "might-generic": (3) Wild mushrooms might be poisonous. In the situation we are considering (3) is true. But does might have a wide-scope or narrow-scope reading with respect to GEN? Clearly (3) can't express that the corresponding generic is epistemically possible - we know that the corresponding generic (1) is false (in the relevant context). That is, the might here doesn't scope over the corresponding generic. Instead, it seems to express the dual of the GEN operator in a way that is reminiscent of what Lewis (1973) said about might-counterfactuals: "if A then might B" is equivalent to "not: if A then would not-B". But the challenge for the dual analysis is to compositionally implement the "Lewisian equivalencies" whereby (3) is equivalent to (4). (4) It is not the case that wild mushrooms aren't poisonous. The challenge, then, is to provide such an account in terms of the denotation of might and GEN. 1 Note that it would not do to analyze (3) as saying that if something is a wild mushroom, then it would normally be such that it is possible that it is poisonous. This treatment is analogous to the contentious "would-be-possible" readings of might-counterfactuals (Lewis 1986: 63-4). But then duality fails. Moreover, since might is epistemic, (3) comes out as false given that some wild mushrooms are easy-to-identify as non-poisonous (cf. Lewis 1973: 80-1). So this, unfortunately, gets the logic wrong. References Asher, Nicholas, and Michael Morreau. 1995. What some generic sentences mean. In The Generic Book, ed. Gregory N. Carlson and Francis Jeffry Pelletier, 300–338. Chicago: University of Chicago Press. Carlson, Gregory N., and Francis Jeffry Pelletier. 1995. The Generic Book. Chicago: University of Chicago Press. Cohen, Ariel. 2004. Existential generics. Linguistics and Philosophy 27:137–168. Delgrande, James P. 1987. A first-order conditional logic for prototypical properties. Artificial Intelligence 33:105–130. Lewis, David. 1973. Counterfactuals. Oxford: Blackwell. Lewis, David. 1975. Adverbs of quantification. In Formal Semantics of Natural Language, ed. Edward L. Keenan, 3–15. Cambridge: Cambridge University Press. Lewis, David. 1986. Postscripts to "Counterfactual dependence and time's arrow". In Philosophical Papers, Volume II, 52–66. Oxford: Oxford University Press. Pelletier, Francis Jeffry, and Nicholas Asher. 1997. Generics and defaults. In Handbook of Logic and Language, ed. Johan van Benthem and Alice G. B. ter Meulen, 1125–1177. Amsterdam: Elsevier. Brian Rabern brian.rabern@gmail.com School of Philosophy, Psychology and Language Sciences University of Edinburgh 3 Charles St. Edinburgh EH8 9AD UK