Yours, Etc.: Origins and Uses of 8 Sign-Offs
early 15c., from Latin dissentire "differ in sentiments, disagree, be at odds, contradict, quarrel," from dis- "differently" (see dis-) + sentire "to feel, think" (see sense (n.)). Related: Dissented; dissenting. The noun is 1580s, from the verb.
Has there ever been a society which has died of dissent? Several have died of conformity in our lifetime. [Jacob Bronowski "Science and Human Values," 1956]