Epistemic modality

Epistemic modality is a sub-type of linguistic modality that encompasses knowledge, belief, or credence in a proposition. Epistemic modality is exemplified by the English modals may, might, must. However, it occurs cross-linguistically, encoded in a wide variety of lexical items and grammatical structures. Epistemic modality has been studied from many perspectives within linguistics and philosophy. It is one of the most studied phenomena in formal semantics. (a) grammatically: through modal verbs (e.g., English: may, might, must; sollen: Er soll ein guter Schachspieler sein "He is said to be a good chess player"), particular grammatical moods on verbs, the epistemic moods, or a specific grammatical element, such as an affix (Tuyuca: -hīyi "reasonable to assume") or particle; or (b) non-grammatically (often lexically): through adverbials (e.g., English: perhaps, possibly), or a certain intonational pattern Lyons 1977 started a long discussion regarding in which environments epistemic modal operators can be embedded and from which environments they are banned. He argues that epistemic modal operators compete for the same position as illocutionary operators, such as the assertion operator, question operator or imperative operator. According to him this explains why most epistemic modals in English are not acceptable embedded under questions or negation. As Lyons finds single lexemes of epistemic modals in English that are used in questions and under negation, he assumes that they must be part of a separate class of epistemic modality–the so called objective epistemic modality, in contrast to subjective epistemic modality—whose operators are considered to be taking the same position in the clause as illocutionary operators. Which modal lexemes convey an objective' epistemic interpretation is subject to much controversy. So far most of the authors who are in favour of a distinct class of objective epistemic modal verbs have not explicitly stated which verbs can be interpreted in an objective' epistemic way and which can only be interpreted in an `subjective' epistemic way.