From the tributes that poured in last night, it was clear he had touched many in his desire to raise the less privileged and thus build a more inclusive society.
Law and Home Affairs Minister K. Shanmugam said in a Facebook post that Nathan's life "revolved around helping others".
He attached a video by social start-up The Hidden Good, which had interviewed people Nathan had helped, and presented it to the former president as a surprise.
One of them is Abdul Rahim Abdul Rahman, a postman who delivered letters to Nathan's office at the Ministry of Foreign Affairs. Nathan then recommended him to work as an office attendant in the ministry, a better job.
Explaining why, Nathan had told him: "Rahim, I want you to just make sure your child completes her education."
For Nathan, it was always Singapore before self, said Shanmugam.
Foreign Minister Vivian Balakrishnan said Nathan's life "was a paragon of devotion to the national cause and care for the most vulnerable members of our community".
Dr Balakrishnan had consulted him before joining politics.
"We discussed the fundamental basis of Singapore's multiracial and multi-religious society, and how important it was to protect this hard-won harmony," he said.
The Hindu Endowments Board echoed this, saying last night it became a founding member of the Inter-Religious Organisation because of the strong belief of Nathan, its chairman from 1983 to 1988.
"He felt it was important for the board, as a religious body, to play an active role in the promotion of inter-religious and inter-racial harmony," it said in a statement.
Nathan's desire to build inclusivity extended to the education sector as well, as he made sure that children from financially needy families would not miss out on education opportunities.
The S R Nathan Education Upliftment Fund, an endowment fund he set up in 2011, supports disadvantaged polytechnic and Institute of Technical Education students.
He would invite recipients to have tea with him at the Eurasian Community House, across his home in Ceylon Road.
The Ministry of Education said last night: "(He) was a firm believer in the importance of building an inclusive society, where no one is left behind even as society progressed.
"In his interactions with youth, Mr Nathan emphasised the values of gratitude and kindness, and encouraged them to be proactive and make meaningful contributions back to society."
Deputy Prime Minister Tharman Shanmugaratnam said last night: "He was active to the end, and never lost his human touch.
"Just in the last few months, he was sending letters to me and others with his sharp observations and advice on various issues, and always in his beautiful handwriting."
Minister for Communications and Information Yaacob Ibrahim said Nathan "embodied the phrase 'society above self' ".
Dr Yaacob, who is also Minister- in-charge of Muslim Affairs, said Nathan's concern for the Malay/Muslim community was "sharp and strong".
"He urged the community to stay focused on developing in tandem with other communities. He was ever ready to assist where he could because he believed that no one should be left behind," he said.
CapitaLand president and group chief executive Lim Ming Yan said that as the head of the organisation's philanthropic arm, Nathan helped shape its approach towards corporate philanthropy and volunteerism.
"Under his stewardship over the last four years, CapitaLand Hope Foundation has gained immeasurably from Mr Nathan's wholehearted sharing of his vast experience gleaned from a lifetime of service to Singapore," said Lim.