Masterpieces is a series of exhibitions which showcase the treasures held by the University’s libraries, museums, archives and galleries. This is the third and final exhibition in the series, in which we want to push the definition of a ‘masterpiece’ to its limits. Focusing on the overall theme of science and medicine, we have chosen items which we feel reflect the themes of ‘science as innovation’, ‘science as art’, and ‘science as statement’. Some of these are famous works such as Charles Darwin’s Origin of Species. Others may be less familiar, such as Arthur Conan Doyle’s medical thesis, written before he invented Sherlock Holmes. Some may challenge and provoke, such as the collection of promotional material produced in the 1980s as Edinburgh led the global fight against HIV. Great ideas and discoveries appear in many ways – sometimes as a magnificent book with coloured plates, sometimes as a tiny scrap of paper with a few words that changed the world.