philosophical doctrine vs ism

philosophical doctrine and ism both are nouns.

Word	Noun	Adjective	Verb	Adverb
philosophical doctrine	Yes	No	No	No
ism	Yes	No	No	No

As nouns, ism is a hypernym of philosophical doctrine; that is, ism is a word with a broader meaning than philosophical doctrine:

philosophical doctrine: a doctrine accepted by adherents to a philosophy
ism: a belief (or system of beliefs) accepted as authoritative by some group or school

Other hypernyms of philosophical doctrine include doctrine, philosophical system, philosophy, school of thought.

philosophical doctrine (noun)	ism (noun)
a doctrine accepted by adherents to a philosophy	a belief (or system of beliefs) accepted as authoritative by some group or school