different between academicist vs academicism

English

academic +? -ist

academicist (comparative more academicist, superlative most academicist)

academic +? -ism

academicism (countable and uncountable, plural academicisms)

(classical studies, sometimes capitalized) The doctrines of Plato's academy; specifically the skeptical doctrines of the later academy stating that nothing can be known; a tenet of the Academic philosophy; state of being Academic. [First attested in the early 17th century.]
(art, literature) Traditional or orthodox formalism; conventionalism.
Speculative thoughts and attitudes.
A mannerism or mode peculiar to an academy.