Severe illness dogged him when he was young, but it could not overcome his determination to succeed. He was an extremely determined man.

Selwyn Carson was born in Lyttelton on 14 October 1923, the fourth child of a London East Ender who had gone to sea at 11, and his London wife. The working-class Lyttelton family was hard up in the Depression. Dr Carson attended Lyttelton School, where he became dux. He shone at sports, especially rugby and tennis, but lived a simple life, in which the beach was the main playground.

At 14, Dr Carson developed life-threatening septicaemia. In those pre-antibiotic days, few people would have survived, but he pulled through. However, he was sick for a long time, causing him to miss much of his early secondary schooling. He completed only two years at Christchurch Boys’ High School.

Then it was off to Canterbury University. As a boarder at Rolleston House, Dr Carson led a social life, claiming to have learned more about beer drinking than science. Nevertheless he ‘scraped through’ a science degree and moved to Dunedin to study medicine.

A bout of Tb afflicted the young medical student, but again he came through. He married Dunedin physiotherapist Marjorie Porteous in his third year, and their family of four started in his fifth year.

Dr Carson worked as a house surgeon at Blenheim, then returned to Christchurch where he started his own practice in Beckenham. The practice thrived and moved premises twice before Dr Carson, with three others, established the Christchurch South Health Centre.

The centre became one of the largest and most progressive general practices in New Zealand. Here Dr Carson pioneered the concept of practice nurses. He also co-authored the Manual for General Practice.

The Manual was published and used worldwide, earning him an international reputation as a leading GP. This led to a 15-month term as Associate Professor of Family Medicine at the King Faisal University in Saudi Arabia, from 1980. He was then President of the Royal New Zealand College of General Practice through the early 1980s and was awarded an honorary fellowship of the Royal Australian College of GPs.

Dr Carson travelled to England in 1966 to study at the Tavistock Clinic under Michael Balint. This started a lifelong interest in psychotherapy, which continued until he retired. He was also an active member of the Christchurch Balint groups for many years.

Dr Carson was never a man to make a fuss. He was passionate about his medical practice and continued working until the age of 72. Then, at 12.30 pm one day, he walked out of his office, dumped his files at the reception desk and said ‘That’s it; I’ve retired.’

He was always quick to make decisions. One day, while the rest of the family was skiing, he bought a new refrigerator, which they found installed when they returned home. Asked why he had bought it, he said the old one had broken down. His wife then explained she had turned it off to defrost.

He was very much a family man, for whom his wife remained the most important person in his life. He doted on his children and was generous to a fault with the extended family.

A voracious reader, Dr Carson also tried his hand at writing and had two thrillers published. After some local readers claimed to recognise themselves as characters in his books, his wife vetoed a third on the grounds that she had to live in Christchurch.

He built the family home in Cashmere in 1963, and, 30 years later, bought and cleared a section and built the apartments in which he and his wife lived.

Believing everyone should learn some Maori, Dr Carson took lessons at Christchurch Polytechnic for three years about the time of his retirement. From then on he used to quiz his grandchildren on the meanings of Maori place names, until the children learned to avoid mention of Maori names.

Dr Selwyn Carson was a keen bridge player and loved to argue foreign politics, on which he had strong views.

He died on 5 October 2003, and is survived by his wife Marjorie, children Simon, Sean, Matthew and Diana, and 11 grandchildren.