This volume provides a comprehensive and even-handed overview of the debate concerning biological origins. This has been a controversial debate ever since Darwin published The Origin of Species in 1859. Invariably the source of controversy has been design. Is the appearance of design in organisms as exhibited in their functional complexity the result of purely natural forces acting without prevision or teleology? Or does the appearance of design signify genuine prevision and teleology, and, if so, is that design empirically detectable and thus open to scientific inquiry? Four main positions have emerged in response to these questions: Darwinism, self-organization, theistic evolution and intelligent design. In this unique survey leading figures in the debate argue for their respective positions in a non-technical, accessible style. Readers are thus invited to draw their own conclusions. Two introductory essays furnish a historical overview of the debate.