empirical vs empiricism

empirical is not a noun while empiricism is a noun.

Word	Noun	Adjective	Verb	Adverb
empirical	No	Yes	No	No
empiricism	Yes	No	No	No

empirical (noun)	empiricism (noun)
	the application of empirical methods in any art or science
	medical practice and advice based on observation and experience in ignorance of scientific findings
	(philosophy) the doctrine that knowledge derives from experience

empirical (adjective)	empiricism (adjective)
derived from experiment and observation rather than theory
relying on medical quackery