philosophical system vs belief

philosophical system and belief both are nouns.

Word	Noun	Adjective	Verb	Adverb
philosophical system	Yes	No	No	No
belief	Yes	No	No	No

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

philosophical system: a belief (or system of beliefs) accepted as authoritative by some group or school
belief: any cognitive content held as true

philosophical system (noun)	belief (noun)
a belief (or system of beliefs) accepted as authoritative by some group or school	any cognitive content held as true
	a vague idea in which some confidence is placed