uprightness vs rectitude

uprightness and rectitude both are nouns.

Word	Noun	Adjective	Verb	Adverb
uprightness	Yes	No	No	No
rectitude	Yes	No	No	No

As nouns, uprightness and rectitude are synonyms defined as:

uprightness and rectitude: righteousness as a consequence of being honorable and honest

uprightness (noun)	rectitude (noun)
righteousness as a consequence of being honorable and honest	righteousness as a consequence of being honorable and honest
position at right angles to the horizon
the property of being upright in posture