Speaking at its headquarters, former President Pranab Mukherjee on Thursday did some plain-speaking on nationalism and patriotism to RSS cadre telling them that India's multiple faiths and cultures made it tolerant and that the soul of the nation resided in its pluralism and secularism.

Calling for a dialogue to balance competing interests and reconcile them, he made it clear that hatred dilutes nationalism and intolerance will dilute national identity. "Divergent stands in public discourse have to be recognised."

Sharing "some truths that I have internalized during my 50 year long public life" as a parliamentarian and administrator, he said the soul of India resided in "pluralism and tolerance".

"This plurality of our society has come through assimilation of ideas over centuries. Secularism and inclusion are a matter of faith for us. It is our composite culture which makes us into one nation," he said addressing the third year annual training camp at the RSS headquarters here even as his acceptance of the invitation to the event came in for strong criticism from Congress leaders and Left parties.

Invoking the vision of Mahatma Gandhi, Jawaharlal Nehru and Sardar Patel, Mukherhjee said India's nationhood was not one language, one religion or one enemy.

"It's the perennial one universalism of 1.3 billion people who use more than 122 languages, 1,600 dialects in their every day lives, practice seven major religions, belong to three major ethnic groups... live under one system, one flag and one identity of being 'Bharatiya' and have no enemies. That is what makes India a diverse and united nation," he said, speaking in English and peppering his speech with some words and phrases from his mother tongue Bengali.

He said intolerance diluted nationalism and hate was destroying people. "Only a non-violent society can ensure participation of all sections of people in the democratic process, especially marginalized and dispossesed. We must move from violence, anger and conflict to peace, harmony and happiness. Our motherland is asking for that. Our motherland deserves that," Mukherjee said in his 30-minute address.

The former President surprised the political world when he accepted RSS chief Mohan Bhagwat's invitation to attend the organisation's event at its headquarters. While the Congress officially maintained silence, its leaders including Anand Sharma, Ahmed Patel and his own daughter Sharmistha were critical of it.

As television channels beamed images of Mukherjee watching a drill by RSS cadres in the company of Bhagwat, Sharma tweeted that the image of Mukherjee at the RSS headquarters has anguished millions of Congress workers in the country.

Earlier, Mukherjee, who had strongly denounced the saffron founthead during his entire political career, visited the memorial of RSS founder K.B. Hedgewar and wrote in the visitors' book: "Came here to pay my respect and homage to a great son of India K.B. Hedgewarji."

On patriotism, the former Congress leader said: "From our Constitution flows our nationalism. The construct of Indian nationalism is Constitutional patriotism which consists of an appreciation of our inherited and shared diversity, readiness to enact one citizenship at different levels and an ability to self correct and learn from others."

At the outset, he said he wanted to share with RSS cadres his understanding of the concepts of nation, nationalism and patriotism in the context of India -- that is Bharat. "These three concepts are so closely intertwined that it's difficult to discuss any one of them in isolation."