haeccitas and quidditas

Haeccitas is a philosophical term associated with the philosopher Duns Scotus used to indicate the “thisness” of things, the singularity of a situation, the phenomenon of the here-and-now, the flesh that you can feel and feels pain. I first ran across this in an terrific article by Marina Warner in TLS “Apocalypse and its aftermath” (August 17, 2005).

Quidditas is a philosophical term referring to the essential “whatness” of a thing, or the ultimate substance of which that thing is made. The term was coined by the medieval Scholastics to describe a concept of “substance” they encountered whilst translating Aristotle.