Aristotle is a rarity in the history of philosophy and science - he is a towering figure in the history of both disciplines. Moreover, he devoted a great deal of philosophical attention to the nature of scientific knowledge. How then do his philosophical reflections on scientific knowledge impact his actual scientific inquiries? In this book James Lennox sets out to answer this question. He argues that Aristotle has a richly normative view of scientific inquiry, and that those norms are of two kinds: a general, question-guided framework applicable to all scientific inquiries, and domain-specific norms reflecting differences in the target of inquiry and in the means of observation available to researchers. To see these norms of inquiry in action, the second half of this book examines Aristotle's investigations of animals, the soul, material compounds, the motions of heavenly bodies, and respiration. 'Aristotle’s methodology of discovery is as full of genius and sophistication as his extraordinary discoveries themselves. No one interested should miss this major study by a leading expert.' Sarah Broadie, Bishop Wardlaw Professor of Philosophy, University of St Andrews Argues that, for Aristotle, scientific inquiry is governed both by a domain-neutral erotetic framework and by domain-specific norms. James G. Lennox is Professor Emeritus of History and Philosophy of Science at the University of Pittsburgh. He has published widely on the history and philosophy of biology, with a focus on Aristotle, William Harvey, Charles Darwin and Darwinism. His books include Aristotle's Philosophy of Biology (Cambridge, 2001) and a translation, with commentary, of Aristotle: On the Parts of Animals (2001) in the Clarendon Aristotle Series.