Charles Birch started out as an agricultural scientist, switched to biology and ecology and soon confronted questions that were to occupy him for the rest of his life: where humankind was really going, preoccupied as it was with its its eternal conflicts and relentless pursuit of wealth. The world could not sustain this forever and he believed progress could only be made when spiritual values were married to the empirical world he probed as a scientist.
These were fundamental questions, he believed, which had to be asked in a century which saw 2 billion people on the planet and 6 billion, and counting, at the end of it, where resources obviously were finite, the global ecology was being rapidly depleted and the harmony that Christianity preached appeared further from reach than ever.
Birch's quest for answers took him into academia. For 25 years he was Challis Professor of Biology at the University of Sydney and had visiting professorships in Sao Paulo, Brazil, Minnesota and California. His strong advocacy of social responsibility for the World Council of Churches earned him the Templeton Prize in 1990 for science and religion.
Louis Charles Birch was born in Melbourne on February 8, 1918, the son of Harry Birch, a New Zealand-born bank manager with the ES&A Bank, and his Irish-born wife, Nora. He had a twin brother, Sidney, and an older brother, Hugh. Birch attended Scotch College, Melbourne, and graduated in agriculture at the University of Melbourne in 1939.
From there he went to the Waite Agricultural Research Institute at the University of Adelaide, working for six years under the supervision of Dr Herbert Andrewartha, who had a great influence on him, teaching him ''to think'' and to discover ''the social responsibility of the scientist'', as Birch expressed it. ''In view of the enormous transformation of the modern world as a result of science and technology, the scientist is responsible for much that has happened both good and bad. This understanding is based on the premise that science is not value free.''
In 1941, Birch took a master of science degree at the University of Adelaide then National Service, working on projects such as preserving the stockpile of wheat, which could not be exported and was in danger of rotting. His brother Hugh went off to pilot flying boats for the RAAF over the English Channel but Charles, though knowing Hitler had to be stopped, had a strong aversion for war, making him virtually a pacifist.
At war's end, drawn to teaching and students, he decided on a change of direction and took the opportunity of a research fellowship at the University of Chicago in 1946 to study biology. He had also had his interest in religion enriched by his association with the Student Christian Movement, which moved him away from
the rather rigid evangelical outlook of Anglican Melbourne to a more questioning, liberal view of the faith.
In 1947 he studied animal population dynamics at Oxford University and in 1948 joined the staff of the University of Sydney as a senior lecturer in zoology. Serving also as vice-master of the university's Wesley College, he progressed through the academic ranks to his appointment as Challis Professor of Biology in 1958.
When the renowned anthropologist Margaret Mead told the World Council of Churches it should have a program on science, technology and the future, Birch was invited to become part of it. He remained in the program for 20 years. For 13 years he was the council's vice-moderator, church and society. Birch met many of the world's great thinkers in population and genetics, including Paul Ehrlich. For years he was prominent in the Zero Population Growth movement, which attracted widespread support in Australia.
When the Vietnam War started in earnest in 1965, Birch was at the forefront of opposition, addressing huge meetings on the front lawn of Sydney University. He risked arrest through his membership of Committee on Conscience, which supported and gave free legal advice to conscientious objectors. ''When that became public I received hundreds of telegrams of support from trade unions throughout Australia,'' he said later.
For 10 years Birch was active in the Wayside Chapel, which had been developed by the Reverend Ted Noffs into a community forum for people who were normally at the fringes of society. He participated in Friday night discussion groups and on Sunday nights at Question Time. Birch, answering a question on world overpopulation, said that one solution would be for each person to try to eat another. One of the fringe-dwellers called out: ''Well, I'll have you!'' Noffs's enlightened policies were seen to work. A crisis centre at the chapel was manned not by detached professionals but by people who had been through crises themselves.
Birch's Templeton Prize was one of a host of awards. He enjoyed fellowship of the Australian Academy of Science, the Club of Rome and the American Association for the Advancement of Science. He had nine books and 150 papers published, the former including The Distribution and Abundance of Animals with H.G. Andrewartha (1954), Nature and God (1965); Genetics and the Quality of Life (1975); The Liberation of Life: From Cell to the Community (1981); On Purpose (1984); Regaining Compassion: for Humanity and Nature (1993) and his last book, Science & Soul, published last year.
An underlying theme of these books was process thought, as understood by A.N. Whitehead, Charles Hartshorne and John Cobb. He was to the end a quiet, wistful, far-sighted man whose ideas and outlook are likely to be even more relevant as the decades progress.
Charles Birch never married. He is survived by his twin, Sidney, and sister-in-law, Jenny. A private funeral was held yesterday and a memorial service is being planned for early in the new year.