Ansari's remarks come within days of his strongly pitching for affirmative action for Muslims as a prerequisite to ensure a the success of the government's 'sabka saath sabka vikas' vision.
Delivering the first Ram Manohar Lohia Memorial National Lecture at Gwalior yesterday, Ansari said,"In a democratic society, including ours, the need to accept difference of opinion is an essential ingredient of plurality.
"In that sense, the right of dissent also becomes the duty of dissent since tactics to suppress dissent tend to diminish the democratic essence."
"It has been observed with much justice that the history of progress of mankind is a history of informed dissent," he said, adding dissent as a right has been recognised by the Supreme Court which maintains that restrictions on it have to be reasonable and cannot be arbitrary, excessive or disproportionate.
At yesterday's event also, he quoted Lohia, saying preferential opportunities be given to the underprivileged to deal with the caste system.
Talking about the right of dissent, Ansari quoted one of the academicians to say that "nothing is more fatal for disagreements and dissent than the idea that all of it can be reduced to hidden sub-texts or external agendas".
