aetiology vs philosophy

aetiology and philosophy both are nouns.

Word	Noun	Adjective	Verb	Adverb
aetiology	Yes	No	No	No
philosophy	Yes	No	No	No

As nouns, philosophy is a hypernym of aetiology; that is, philosophy is a word with a broader meaning than aetiology:

aetiology: the philosophical study of causation
philosophy: the rational investigation of questions about existence and knowledge and ethics

aetiology (noun)	philosophy (noun)
the philosophical study of causation	the rational investigation of questions about existence and knowledge and ethics
the cause of a disease	a belief (or system of beliefs) accepted as authoritative by some group or school
	any personal belief about how to live or how to deal with a situation