Biologists study life in its various physical forms, while philosophy of biology seeks answers to questions about the nature, purpose, and impact of this research. What permits us to distinguish between living and nonliving things even though both are made of the same minerals? Is the complex structure of organisms proof that a creative force is working its will in the physical universe, or are existing life forms the random result of an evolutionary process working itself out over eons of time? What moral questions arise regarding genetic engineering or cloning? What is more relevant to human nature: genetics or sociocultural influences? Are we unique in the universe or might other forms of life exist out there somewhere? Is Darwinism the death-knell of God?