He warned of dangers to the republic if there was no unity and respect for diversity, secularism and pluralism.
"The nation is deeply concerned at the recent tragic instances of blatant violation of the right to freedom of thought, belief, speech and expression in our country by some violent extremist groups.
"The assault or murder of thinkers for no more than disagreement with their views, or (of people) because of the food they eat, or their caste, cannot be justified on any grounds. Nor can the suppression of the right to dissent be allowed," he said in his inaugural address at a conference here ahead of the 125th birth anniversary of Jawaharlal Nehru.
The senior Congress leader said that all right-thinking people have condemned such incidents in the strongest term as an "assault on the nation".
Unity and respect for diversity, secularim and pluralism are vital of the survival of the republic, he said, adding that peace is essential not only for human existence and survival, but also for economic and intellectual growth and development.
He said suppression of dissent or free speech poses a grave danger for economic development. "There can be no free market without freedom.
