quintessence vs inwardness

quintessence and inwardness both are nouns.

Word	Noun	Adjective	Verb	Adverb
quintessence	Yes	No	No	No
inwardness	Yes	No	No	No

As nouns, inwardness is a hypernym of quintessence; that is, inwardness is a word with a broader meaning than quintessence:

quintessence: the purest and most concentrated essence of something
inwardness: the choicest or most essential or most vital part of some idea or experience

Other hypernyms of quintessence include center, centre, core, essence, gist, heart, heart and soul, kernel, marrow, meat, nitty-gritty, nub, pith, substance, sum.

quintessence (noun)	inwardness (noun)
the purest and most concentrated essence of something	the quality or state of being inward or internal
the most typical example or representative of a type	preoccupation with what concerns human inner nature (especially ethical or ideological values)
the fifth and highest element after air and earth and fire and water; was believed to be the substance composing all heavenly bodies	preoccupation especially with one's attitudes and ethical or ideological values
	the choicest or most essential or most vital part of some idea or experience