This study of the origins and progress of Greek science focuses especially on the interaction between scientific and traditional patterns of thought from the sixth to the fourth century BC. It begins with an examination of how particular Greek authors deployed the category of "magic," sometimes attacking its beliefs and practices; these attacks are then related to their background in Greek medicine and philosophical thought. In his second chapter Lloyd outlines developments in the theory and practice of argument in Greek science and assesses their significance. He next discuses the progress of empirical research as a scientific tool from the Presocratics to Aristotle. Finally, he considers why the Greeks invented science, their contribution to its history, and the social, economic, ideological and political factors that had a bearing on its growth.