he importance and influence of Charles Darwin's theory of evolution by natural selection can scarcely be exaggerated. A century after Darwin's death, the great evolutionary biologist and historian of science, Ernst Mayr, wrote, 'The worldview formed by any thinking person in the Western world after 1859, when On the Origin of Species was published, was by necessity quite different from a worldview formed prior to 1859... The intellectual revolution generated by Darwin went far beyond the confines of biology, causing the overthrow of some of the most basic beliefs of his age.'1 Adrian Desmond and James Moore, Darwin's biographers, contend, 'Darwin is arguably the best known scientist in history. More than any modern thinker--even Freud or Marx--this affable old-world naturalist from the minor Shropshire gentry has transformed the way we see ourselves on the planet.'2 In the words of the philosopher Daniel C. Dennett, 'Almost no one is indifferent to Darwin, and no one should be. The Darwinian theory is a scientific theory, and a great one, but that is not all it is... Darwin's dangerous idea cuts much deeper into the fabric of our most fundamental beliefs than many of its sophisticated apologists have yet admitted, even to themselves.'3 Dennett goes on to add, 'If I were to give an award for the single best idea anyone has ever had, I'd give it to Darwin, ahead of Newton and Einstein and everyone else. In a single stroke, the idea of evolution by natural selection unifies the realm of life, meaning, and purpose with the realm of space and time, cause and effect, mechanism and physical law.'4 The editors of the Cambridge Companion to Darwin begin their introduction by stating, 'Some scientific thinkers, while not themselves philosophers, make philosophers necessary. Charles Darwin is an obvious case. His conclusions about the history and diversity of life--including the evolutionary origin of humans--have seemed to bear on fundamental questions about being, knowledge, virtue and justice.'5 Among the fundamental questions raised by Darwin's work, which are still being debated by philosophers (and others) are these: 'Are we different in kind from other animals? Do our apparently unique capacities for language, reason and morality point to a divine spark within us, or to ancestral animal legacies still in evidence in our simian relatives? What forms of social life are we naturally disposed towards--competitive and selfish forms, or cooperative and altruistic ones?'6 As the editors of the volume point out, virtually the entire corpus of the foundational works of Western philosophy, from Plato and Aristotle to Descartes to Kant to Hegel, has had to be re-examined in the light of Darwin's work. Darwin continues to be read, discussed, interpreted, used, abused--and misused--to this day. As the philosopher and historian of science, Jean Gayon, puts it, '[T]his persistent positioning of new developments in relation to a single, pioneering figure is quite exceptional in the history of modern natural science.