inscrutability of reference See INDETERMINACY OF. TRANSLATIO. insolubilia, sentences embodying a semantic antinomy such as the liar paradox. Insolubilia were used by late medieval logicians to analyze self-nullifying sentences, the possibility that all sentences imply that they are true, and the relation between spoken, written, and mental language. At first, theorists focused on nullification to explicate a sentence like ‘I am lying’, which, when spoken, entails that the speaker ‘says nothing.’ Bradwardine suggested that such sentences signify that they are at once true and false, prompting Burley to argue that all sentences imply that they are true. Roger Swineshead used insolubilia to distinguish between truth and correspondence to reality; while ‘This sentence is false’ is itself false, it corresponds to reality, while its contradiction, ‘This sentence is not false,’ does not, although the latter is also false. Later, Wyclif used insolubilia to describe the senses in which a sentence can be true, which led to his belief in the reality of logical beings or entities of reason, a central tenet of his realism. Pierre d’Ailly used insolubilia to explain how mental language differs from spoken and written language, holding that there are no mental language insolubles, but that spoken and written language lend themselves to the phenomenon by admitting a single sentence corresponding to two distinct mental sentences. See also BURLEY, D’AILLY, OXFORD CALCULA- TORS , SEMANTIC PARADOXES , WYCLIF. S.E.L.