This volume includes new publications of Max Planck's book "A Survey of Physics: A Collection of Lectures and Essays" and his Nobel Prize Address "The Origin and Development of the Quantum Theory." Planck's book contains eight essays on what he considered to be the most important and urgent issues in physics at the beginning of the 20th century. As Planck himself put it "the essays should reach a wider circle of readers," the book should prove attractive to experts, students and all interested in the foundations and philosophy of physics. Physicists would, undoubtedly, be most interested in the last essay (and in Planck's Nobel Prize Address) in which Planck gave a detailed account of how he overcame the difficulties on the road that led him to the quantum theory.