asceticism vs school of thought

asceticism and school of thought both are nouns.

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

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

asceticism: the doctrine that through renunciation of worldly pleasures it is possible to achieve a high spiritual or intellectual state
school of thought: a belief (or system of beliefs) accepted as authoritative by some group or school

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

asceticism (noun)	school of thought (noun)
rigorous self-denial and active self-restraint	a belief (or system of beliefs) accepted as authoritative by some group or school
the trait of great self-denial (especially refraining from worldly pleasures)
the doctrine that through renunciation of worldly pleasures it is possible to achieve a high spiritual or intellectual state