-ism and -ity

-ism and -ity

These noun-forming suffixes are derived via Old French from the Latin noun endings -ismus and -itas. The suffix -ism forms nouns of action based on verbs or adjectives (baptism, criticism, heroism), and has a number of special meanings:

(1) a political or religious movement or system of thought (atheism, Buddhism, realism),

(2) a pathological condition (alcoholism, Parkinsonism),

(3) a special feature or peculiarity of language (Americanism, Gallicism),

(4) a basis of prejudice or discrimination (a 20c development first apparent in racism, and more recently in sexism, ageism, speciesism, etc.).

The suffix -ity has the special role of forming abstract nouns from comparative forms (inferiority, majority) but in general has the more limited meaning ‘a quality or condition, or an instance of it’ (authority, humility, purity). Some words have produced nouns (with different meanings) in both -ism and -ity (liberalism / liberality, modernism / modernity, realism / reality, etc.).