'A scientist must be freely imaginative and yet sceptical, creative and yet a critic... There is poetry in science, but also a lot of book-keeping.' So says scientist Sir Peter Medawar, Nobel Prize-winner for his research in immunology. His discoveries have led to skingrafting and organ transplants both becoming commonplace types of treatment. For this and other work he has been knighted, awarded the Order of Merit and Companion of Honour, but he is far more than scientist alone. Something of a Renaissance man, he has written on many subjects of wide appeal, most recently in his latest book, Plato's Republic.