genuinity

The Latin adjective genuinus meant native, innate, born in the household. Roman writers used it to distinguish something truly belonging to a place or person from an imitation. Cicero used genuinus to describe natural talent, and Pliny used it for native species. The word carried no suspicion of fraud; it simply meant: from the source.

English borrowed genuine in the 16th century, and by the 1650s writers needed a noun form. Two competing formations emerged: genuineness, following the Germanic pattern of adjective plus -ness, and genuinity, following the Latin pattern of stem plus -ity, as in unity from unus. Thomas Blount's 1656 Glossographia records genuinity as the philosophical quality of being authentic or unfeigned.

The two words never quite sorted themselves out. Genuineness won the frequency war in common speech, but genuinity persisted in philosophical and theological writing well into the 19th century. Samuel Taylor Coleridge used it in his 1817 Biographia Literaria when discussing the authenticity of texts. John Henry Newman used it in the 1840s in debates about doctrinal authority.

Today genuinity appears in academic philosophy, particularly in existentialist and phenomenological writing influenced by Heidegger's concept of Eigentlichkeit. The word fills a niche that genuineness cannot quite fill: a structural or essential quality, rather than a surface observation. Where genuineness describes what we see, genuinity describes what is present from within.