Sir Peter Brian Medawar was a Brazilian-born English scientist best known for his work on how the immune system rejects or accepts organ transplants. He was co-winner of the 1960 Nobel Prize in Physiology or Medicine with Sir Frank Macfarlane Burnet.

Early years
Medawar was born on February 28, 1915, in Rio de Janeiro of a British mother and a Lebanese father. Medawar was educated at Marlborough College, England, where he went in 1928. Leaving this College in 1932, he went to Magdalen College, Oxford, to study zoology under Professor J. Z. Young where he gained admission of Christopher Welch Scholarship and senior Demyship to back up his scientific research. After taking his bachelor's degree at Oxford, Medawar worked for a time at Sir Howard Florey's School of Pathology at Oxford and there became interested in research in fields of biology that are related to medicine.

Early research
Medawar's earlier research, done at Oxford, was on tissue culture, the regeneration of peripheral nerves and the mathematical analysis of the changes of shape of organisms that occur during this development. During the early stages of the Second World War he was asked by the Medical Research Council to investigate why that skin taken from one human will not form a permanent graft on the skin of another person,and this work enabled him to establish theorems of transplantation immunity which formed the basis of his further work on this subject. His involvement with transplant research began in 1949, when Burnet advanced the hypothesis that during embryonic life and immediately after birth, cells gradually acquire the ability to distinguish between their own tissue substances and unwanted cells and foreign material.

Outcome of Research
Medawar was awarded his Nobel Prize in 1960 with Burnet for their work in tissue grafting which is the basis of organ transplants and their discovery of acquired immunological tolerance. This work was used in dealing with skin grafts required after burns. Medawar's work resulted in a shift of emphasis in the science of immunology from one that attempts to deal with the fully developed immunity mechanism to one that attempts to alter the immunity mechanism itself, as in the attempt to suppress the body's rejection of organ transplants.

Achievements
Medawar was professor of zoology at the University of Birmingham (1947-51) and the University College London (1951-62), in 1962 he was given the position of the director of the National Institute for Medical Research, professor of experimental medicine at the Royal Institution (1977-83), and president of the Royal Postgraduate Medical School (1981-87). Medawar was a scientist of great inventiveness who was interested in many other subjects including opera, philosophy and cricket. He was a writer of great fluency, clarity and wit.

His books are among the very best examples of a great scientist explaining the beauty and meaning of science in a manner valuable to fellow scientists as well as to laymen. His books include The Art of the Soluble, a book of essays, some later reprinted in Pluto's Republic, Advice to a Young Scientist, Aristotle to Zoos (with his wife Jean Shinglewood Taylor), and his last, in 1986, Memoirs of a Thinking Radish, a brief autobiography. He was knighted in 1965 and awarded the Order of Merit in 1981. Medawar died in 1987.

Quotations

"To abdicate from the rule of reason and substitute for it an authentication of belief by the intentness and degree of conviction with which we hold it can be perilous and destructive. Religious beliefs give a spurious spiritual dimension to tribal enmities."

"It goes with the passionate intensity and deep conviction of the truth of a religious belief, and of course of the importance of the superstitious observances that go with it, that we should want others to share it -- and the only certain way to cause a religious belief to be held by everyone is to liquidate nonbelievers. The price in blood and tears that mankind generally has had to pay for the comfort and spiritual refreshment that religion has brought to a few has been too great to justify our entrusting moral accountancy to religious belief."

"I regret my disbelief in God."