議 (Kanji for discussion)

Onyomi

I will say something righteous during the discussion

会議(かいぎ)

a conference ★★★☆☆
会 (big meeting) + 議 (discussion) = 会議 (a conference)

議論(ぎろん)

argument ★★☆☆☆
議 (discussion) + 論 (make a case for) = 議論 (argument)

not quite an argument, but definitely a spirited loud discussion.

You discuss things when you SPEAK.

Righteousness is something you have inside you, but politeness is how you treat other PERSONs.

That's why righteous has no left radical ! It's an INTERNAL virtue.