These essays and speeches by the Nobel Prize-winning physicist date from 1934 to 1958. Rather than expositions on quantum physics, the articles are philosophical in nature, exploring the relevance of atomic physics to many areas of human endeavor. Topics include light and life, biology and atomic physics, natural philosophy and human cultures, unity of knowledge, atoms and human knowledge, and physical science and the problem of life. An essay in which Bohr and Einstein discuss determinism in quantum theory and the future of the wave equation theory is of particular note.