When 72-year-old Lionel De Souza comes across an insensitive remark made against a racial or religious group, he does not ignore it.
He takes action, like making a police report when former NTUC employee Amy Cheong posted an expletive-laden rant on Facebook disparaging Malay weddings in October 2012. The reason he is so cautious is because of his past experiences, he says, urging today's youth not to slip into uttering racial slurs even among friends.
"I witnessed the 1964 riots, and I don't want it to happen again," said Mr De Souza, who is secretary of Hougang's Inter-Racial and Religious Confidence Circle (IRCC).
"Singaporeans need to know that (misunderstandings) are caused by ignorance. By understanding someone's religion and race, these things won't blow up."
He was one of more than 200 members of Singapore's pioneer generation honoured yesterday for their active role in promoting racial and religious harmony here.
Minister of Culture, Community and Youth Lawrence Wong said in a speech that Singapore's harmony was a miracle, but not one borne out of chance. He said: "Our pioneers... made it happen."
Turning to them, he added: "You helped to create a Singaporean Singapore. You worked hard in your own capacities as religious and community leaders to pave the Singaporean way for social harmony."
Some of those feted yesterday included the first batch of leaders of the IRCCs - a community-level initiative to strengthen inter-faith and inter-ethnic ties and mediate racial and religious conflicts in the community.
Others were past and present members of the National Steering Committee on Racial and Religious Harmony - a panel comprising leaders of the main religious groups and key community leaders to promote dialogue between the groups.
Mr Koh Lian Huat, chairman of Tampines East IRCC, said he appreciated that his efforts were being recognised. "But the award goes to the whole community, not just me," said the 74-year-old.
Like Mr De Souza, many there stressed that it was important not to take Singapore's harmony for granted.
Dr Karunanithy Ramasamy, 78, a retired associate professor and vice-chairman of the Telok Blangah IRCC, said: "We must forever be sensitive about racial and religious issues... Before the riots, there was the kampung spirit - but overnight, it became chaos."
Army captain (Ret) Shamsudin Shadan, 83, having lived through the riots, also highlighted the need to be sensitive to Singapore's racial and religious fault lines.
In 1950, the Maria Hertogh riots saw Malays clashing with Caucasians and Eurasians. In 1964, two riots broke out between the Chinese and the Malays.
Sister Maria Sim, 69, from the Zhenghua IRCC, said: "We took so long to build (the peace). Sometimes, unthinkingly, and with a little bit of foolishness, you can break that cohesiveness in society."