In addition to being one of the world's most influential philosophers, Aristotle can also be credited with the creation of both the science of biology and the philosophy of biology. He was the first thinker to treat the investigations of the living world as a distinct inquiry with its own special concepts and principles. This book focuses on a seminal event in the history of biology - Aristotle's delineation of a special branch of theoretical knowledge devoted to the systematic investigation of animals. Aristotle approached the creation of zoology with the tools of subtle and systematic philosophies of nature and of science that were then carefully tailored to the investigation of animals. The papers collected in this volume, written by a pre-eminent figure in the field of Aristotle's philosophy and biology, examine Aristotle's approach to biological inquiry and explanation, his concepts of matter, form and kind, and his teleology.