ABSTRACT
Among the many types of expression in our language whieh are used to qualify something, some have attraeted more attention than others and beeome the subjeet of formal investigations . Most prominent among these are the qualifieations ' neeessarily', 'possibly', 'eontingently', the so-called alethie modalit ies, whieh many philosophers since antiquity have feit to be of partieular philosophical importanee . Among other modalities whose formal properties have been studied are the epistemie ones (' It is known that . . .', ' It is not known that . . .', ete.), some moral modes, e.g., the modes of obligat ion, of the deontie modalit ies (' It is obligatory that . . .' , 'It is forbidden that .. .' , etc.).' Many formal feature s reeur from one type of these modalities to another. Professor G. H. von Wright,2among others, has pointed out that many of these features are found also in quantifieation theory. Thus , e.g., ' It is necessary that . . .' behaves in many ways like the universal quantifier, and 'It is possible that ... ' like the existential quantifier. This has led von Wright to eonsider quantifieations "existential modalities."
