Optative validity can be defined in terms of fulfillment: an optative sentence Q is the logical consequence of a set of optative sentences P and factual sentences C if and only if the desires expressed in P cannot be fulfilled under circumstances C unless the desire expressed by Q is fulfilled too.
optative(Used to characterize how non-cognitivist theories treat evaluative terms in embedded/unasserted positions)
A semantic kind for expressions like 'X is good' when used in unasserted contexts, where the expression functions as an expression of desire or wish rather than a truth-apt claim
validity(Formal logic; distinguished from syntactic deducibility)
The model-theoretic counterpart to deducibility; an argument is valid if its conclusion is true under every interpretation in which its premises are true
This is a telling objection against some forms of emotivism which portray moral judgments as mere expressions of raw feeling, analogous to cries of ecstasy or groans of pain. But Russell is better placed to meet this difficulty, since in his view judgments about what is ultimately good and bad are disguised optatives, designed to express desires or wishes of a certain kind. And it is possible to construct a rudimentary concept of logical consequence (and hence of validity) that applies to argume