Stephen Hawking, the physicist, was last night awarded the Presidential Medal of Freedom, America's highest civilian honour.

Bestowing the medal on Professor Hawking, whose book A Brief History of Time remained a bestseller for a record 237 weeks, President Obama said: "From his wheelchair, he has led us on a journey to the farthest and strangest reaches of the cosmos. In so doing, he has stirred our imagination and showed us the power of the human spirit."

Mr Obama joked that he would not try to explain the 67-year-old scientist's work.

But Mr Obama may have been happier to receive than to give when Mr Hawking defended Mr Obama’s health care plans this week, saying: “I wouldn’t be here today if not for the NHS.”

The comments were in direct response to a conservative editorial recently published which incorrectly used Mr Hawking as an example of the problems with socialised health care.

The piece, in Investors Business Daily, which took aim at Mr Obama’s health care overhaul, claimed: “People such as Stephen Hawking wouldn’t have a chance in the UK, where the National Health Service would say the life of this brilliant man, because of his handicaps, is essentially worthless.”

Professor Hawking, Lucasian Professor of Mathematics at Cambridge University, was among 16 other recipients of the medal, who were described by Mr Obama as extraordinary "agents of change."

Other recipients include legend Billie Jean King, South African cleric and civil rights activist Archbishop Desmond Tutu, film star Sidney Poitier and former Irish president Mary Robinson at a ceremony in the White House.

Senator Edward Kennedy, who has been battling brain cancer and was not present. The former Supreme Court Justice Sandra Day O'Connor and Nobel Peace Prize laureate Muhammad Yunus, who pioneered "microloans" to provide credit to poor people who lack collateral were also honoured.

Mr Obama, awarding his first presidential medals, also gave a posthumous award to gay rights activist and San Francisco, California, politician Harvey Milk, who was assassinated in 1978.

Reflecting on those receiving the honour, Mr Obama said: "In a moment when cynicism and doubt too often prevail, when our obligations to each other are too often forgotten and when the road ahead can seem too long or hard to tread, these extraordinary men and women, these agents of change remind us that excellence is not beyond our abilities, that hope lies around the corner and that justice can still be won in the forgotten corners of the world.

"They remind us that we each have it within our powers to fulfil dreams, to advance the dreams of others and remake the world for our children."

Explore UK News

• Crime News

• Education News

• Health News

• Scotland News

Times Recommends

• Times Christmas appeal: Letter from the Editor
• Conferences — what a waste of money
• Schools supremo learns a painful lesson