Paul Dirac, who died in 1984, was without question one of the greatest physicists of the twentieth century. His revolutionary contribution to modern quantum theory is remembered for its insight and creativity. He is especially famous for his prediction of the magnetic moment and spin of the electron and for the existence of antiparticles. He was awarded the Nobel Prize for physics in 1933 at the age of 31. In this memorial volume, 24 of Dirac's friends, colleagues and contemporaries remember him with affection. There are chapters describing Dirac's personality, and many anecdotes about the man with a reputation for silence. Other chapters describe Dirac's science and its impact on modern physics.