ISBN-13: 9780674896666 / Angielski / Miękka / 1989 / 575 str.
A collection of 28 essays, five previously unpublished, grouped into nine categories: Philosophy, Natural Selection, Adaptation, Darwin, Diversity, Species, Speciation, Macroevolution, and Historical Perspective. The book, Ernst Mayr notes in the Foreword, is an attempt "to strengthen the bridge between biology and philosophy, and point to the new direction in which a new philosophy of biology will move."