I referenced http://english.stackexchange.com/a/22445/50720 but it doesn't apply for these nouns?
suasion = [mass noun] formal
Persuasion as opposed to force or compulsion:
I also tried http://thecommonparlance.blogspot.com/2007/10/suasion-v-persuasion.html and http://sprachgefuhl.blogspot.com/2011/06/suasion-persuasion.html but these look tentative.