Quiddities, ecceities
To My Followers from Folly Speaks

[Was added in 1512.]

Quiddities or essences defined the nature of particular objects whether or not they had being or existence. Ecceities were important in the Scotist reaction against Thomist realism. They designated individual natures not really but only 'formally objectively' distinct from a common or universal nature. Forms were the object of intellectual abstractions conferring reality and numerical distinction for the Aristotelian scholastics on objects whose other component was 'prime' or undifferentiated matter.