Interweaving science and metaphysics, The Principle of Relativity presents what is commonly acknowledged as the most interesting alternative to Einstein's general theory of relativity. The great mathematician and philosopher Alfred North Whitehead furthermore spells out his view of geometry, space-time, and Nature in this intriguing book. Originally published in 1922, the book offers a different paradigm from Einstein's, elegant and simple in its mathematical formulation with its own philosophical background and agenda. Few other books exemplify as it does the intricate inter-relations between physics and philosophy. Scholars from both domains shall find here much to chew on, as well as the layman who is interested in the history of ideas of the twentieth century.