positive vs optimistic

positive is a noun but optimistic is not a noun.

Word	Noun	Adjective	Verb	Adverb
positive	Yes	Yes	No	No
optimistic	No	Yes	No	No

positive (noun)	optimistic (noun)
a film showing a photographic image whose tones correspond to those of the original subject
the primary form of an adjective or adverb; denotes a quality without qualification, comparison, or relation to increase or diminution

positive (adjective)	optimistic (adjective)
characterized by or displaying affirmation or acceptance or certainty etc.	expecting the best in this best of all possible worlds
indicating existence or presence of a suspected condition or pathogen	expecting the best
reckoned, situated or tending in the direction which naturally or arbitrarily is taken to indicate increase or progress or onward motion
of or relating to positivism
involving advantage or good
persuaded of; very sure
having a positive charge
marked by excessive confidence
formally laid down or imposed
greater than zero
impossible to deny or disprove