He gave his life for a great cause.
Without a just cause, war cannot be justified.
He gave his life for a great cause.
The revolutionaries fought while upholding their great cause.
There is a just cause behind this fight.
道義 refers to everyday moral duty or ethics, whereas 大義 points to a lofty, world-scale cause worth sacrificing for.
大義 stresses a lofty moral cause or justification, while 旗印 focuses on the symbolic banner or slogan representing that cause.
大儀 (same pronunciation) means 'a bother' or 'tedious task', while 大義 means a great moral cause or justice.
just cause; good reason; pretext; justification · duty to one's country or sovereign
From Middle Chinese 大義 (dɑiH ŋˠiᴇH, 'great righteousness'). The kanji 大 means 'great' and 義 means 'righteousness' or 'justice'.