viewpoint vs posture

viewpoint and posture both are nouns.

Word	Noun	Adjective	Verb	Adverb
viewpoint	Yes	No	No	No
posture	Yes	No	Yes	No

As nouns, posture is a hypernym of viewpoint; that is, posture is a word with a broader meaning than viewpoint:

Other hypernyms of viewpoint include position, stance.

viewpoint (noun)	posture (noun)
a mental position from which things are viewed	the arrangement of the body and its limbs
a place from which something can be viewed	characteristic way of bearing one's body
	capability in terms of personnel and materiel that affect the capacity to fight a war
	a rationalized mental attitude

viewpoint (verb)	posture (verb)
	assume a posture as for artistic purposes
	behave affectedly or unnaturally in order to impress others