Conceptual primitives and semantic universals are the cornerstones of a semantic theory which AnnaWierzbicka has been developing for many years.
Wierzbicka's "Primes and Universals" is a summary of her decades of research.
However, it is interesting to note that although the NSM approach is so effective, Wierzbicka's works are not widely referred to in the works of other semanticists (or for the matter, other linguists) especially outside Australia.
In AnnaWierzbicka's writings the terms 'semantic' and 'conceptual' are used more or less interchangeably, the idea being that semantic primes represent elements of linguistic conceptualisation, i.e.
Wierzbicka's view (like that of Leibniz before her) is that semantic analysis is by its nature a conceptual inquiry, because meanings are not external or objective entities, but, so to speak, creatures of the mind.
In AnnaWierzbicka's 1972 book Semantic Primitives, only 14 semantic primitives were proposed and in her 1980 book Lingua Mentalis, the inventory was not much bigger.