These scientific papers of Richard Feynman are renowned for their brilliant content and the author's striking original style. They are grouped by topic: path integral approach to the foundations of quantum mechanics and quantum field theory, renormalized quantum electrodynamics, theory of superfluid liquid helium, theory of the Fermi interaction, polarons, gravitation, partons, computer theory, etc. Comments on Feynman's topics are provided by the editor, together with biographical notes and a complete bibliography of Feynman's publications.