This facsimile of the first edition of Darwin's epochal work is supplemented with a useful introduction by the great evolutionary biologist Ernst Mayr. "When we go back to the Origin, we want the version that stirred up the Western world", Mayr explains. "The first edition represents Darwin in his most revolutionary spirit and this is the edition that stands as so great a monument in man's intellectual history." The publisher, Harvard University Press, proudly — and correctly — says, "For modern reading and for reference, it is the standard edition of Darwin's greatest work."