pacifism vs school of thought

pacifism and school of thought both are nouns.

Word	Noun	Adjective	Verb	Adverb
pacifism	Yes	No	No	No
school of thought	Yes	No	No	No

As nouns, school of thought is a hypernym of pacifism; that is, school of thought is a word with a broader meaning than pacifism:

pacifism: the doctrine that all violence is unjustifiable
school of thought: a belief (or system of beliefs) accepted as authoritative by some group or school

Other hypernyms of pacifism include doctrine, ism, philosophical system, philosophy.

pacifism (noun)	school of thought (noun)
the doctrine that all violence is unjustifiable	a belief (or system of beliefs) accepted as authoritative by some group or school
the belief that all international disputes can be settled by arbitration