ideopraxist
/ˌɪdɪəˈpraksɪst/ /ˌʌɪdɪəˈpraksɪst/rare
noun
A person whose practice is actuated by an idea, a person who embodies an idea in action.
Origin
Mid 19th century; earliest use found in Thomas Carlyle (1795–1881), author, biographer, and historian. From ideo- + ancient Greek πρᾶξις praxis + -ist.