The life of former president S R Nathan holds many lessons for Singaporeans and they include resilience, duty and country before self, said Prime Minister Lee Hsien Loong.

Mr Lee paid tribute to Mr Nathan's greatness of character in a 15-minute eulogy at his state funeral yesterday afternoon.

"He had hoped that Singaporeans, especially young Singaporeans, would draw a key lesson from his memoirs, which is not to give up," he said. "It is a precept that Mr Nathan lived by."

Such grit and determination, which carried him through a difficult childhood and rise in the public service, was one of four qualities Mr Lee highlighted.

The other three were: he lived life to the fullest, he always did his best for Singapore - even at personal risk and sacrifice, and his great personal integrity and commitment.

"It was his character, as much as his intellect, that led to his achievements in life and took him to the highest office in Singapore."

Mr Lee highlighted the 1974 Laju hostage crisis as an incident that epitomised the qualities of Mr Nathan, who died on Monday at age 92.

Terrorists had hijacked the Laju ferry and, in a protracted negotiation, they agreed to release the hostages in exchange for safe passage to Kuwait.

Mr Nathan, then director of the Security and Intelligence Division, "risked his life" to lead 12 officials who accompanied the terrorists to Kuwait - in effect, as hostages.

"Not many of today's generation know of the Laju incident. Those who do probably do not fully appreciate the magnitude of the decision that Mr Nathan and the other 12 made," said Mr Lee.

"It took great moral and physical courage," he added.

In his speech, Mr Lee gave an overview of Mr Nathan's wide-ranging career which illustrated his lifelong willingness to serve.

After retiring from the Government in 1982, Mr Nathan was asked to be executive chairman of The Straits Times Press company.

He later became High Commissioner to Malaysia and then Ambassador to the United States, where he had to defend Singapore's sentencing of US citizen Michael Fay to caning for vandalism.

When Mr Nathan returned from his Washington stint in 1996, he established the Institute of Defence and Strategic Studies, now the S. Rajaratnam School of International Studies.

"Mr Nathan could have retired from public service into a more pla- cid life in academia," said Mr Lee. "But duty called again. Once again, he put country before self.''

In 1999, he stood for President and was elected.

He served his two terms with dignity and distinction, winning the respect and affection of Singaporeans of all races and from all walks of life, said Mr Lee.

A gracious host to foreign visitors, he also represented Singapore overseas with aplomb.

A generous man, he started the annual President's Challenge campaign to help the less fortunate, Mr Lee added. It raised more than $100 million over 12 years and reminded Singaporeans that everyone has "a part in building a compassionate society".

Being President also meant making tough decisions. Mr Nathan gave good advice, Mr Lee said, when the two worked together as President and Prime Minister for seven years.

During the 2008 global financial crisis, Mr Lee sought permission to draw $5 billion from the national reserves to fund economic measures, and to back a guarantee of all bank deposits in Singapore with $150 billion of the reserves.

After careful consideration, Mr Nathan gave his approval, allowing the crisis to be dealt with decisively and for Singapore to emerge largely unscathed.

"Mr Nathan proved, once again, that he was capable of making tough decisions when the need arose," said Mr Lee.

Even after Mr Nathan retired, he stayed active. He shared his wisdom and experience with the young, and kept up with current affairs and old friends.

Mr Lee and Mr Nathan also kept in touch. He wrote to Mr Lee recently to pass on a message from an old friend.

The four-page note set out the matter, explained the context, and offered to convey a response back to the friend.

With a smile, Mr Lee said: "It could have passed as a staff paper." He did not elaborate on the contents.

Such dedication was emblematic of Mr Nathan's approach.

Mr Lee concluded: "He put heart and soul into every task assigned to him, including the highest office in the land.

"Time and again, he placed nation before self. Quietly and without fuss, he gave his best years and more, to Singapore.

"It is with great sorrow today that we bid farewell to one of Singapore's greatest sons."