hedonism vs moral philosophy

hedonism and moral philosophy both are nouns.

Word	Noun	Adjective	Verb	Adverb
hedonism	Yes	No	No	No
moral philosophy	Yes	No	No	No

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

hedonism: an ethical system that evaluates the pursuit of pleasure as the highest good
moral philosophy: the philosophical study of moral values and rules

Other hypernyms of hedonism include ethics.

hedonism (noun)	moral philosophy (noun)
an ethical system that evaluates the pursuit of pleasure as the highest good	the philosophical study of moral values and rules
the pursuit of pleasure as a matter of ethical principle