Abstract In this book, R. J. Hankinson traces the history of investigation into the nature of cause and explanation, from the beginnings of Ancient Greek philosophy in 600 bc, through the Graeco‐Roman world, to the end of pagan antiquity in c.500 ad The book consists of chapter‐length studies of the Presocratics, Plato, Aristotle (two chapters), Atomism, Stoicism, Scepticism, and Neoplatonism, as well as the Sophistic movement, and Ancient Medicine. Hankinson is principally concerned with the following questions: ‘What did the Greeks understand by a cause?’, and ‘How did the Greeks conceive adequacy in explanation?’. The Ancient Greeks (excepting the Sceptics) are united in their belief that the world and at least some of its process can be rendered intelligible, and that this can be rendered by an inquiry into the nature of things, with reasoned argument as the appropriate method of exhibiting the real structure of the world. Thus, the Greek thinkers set the standards for science, because they are guided by logic and observation in their analysis of causation; but one can also recognize the growth of interest among the Greeks in the nature of explanation itself. The question that becomes central to the development of Greek philosophical science is whether nature can be understood in terms of teleology, or solely in terms of mechanical laws. Hankinson is interested in how the concepts of cause and explanation function in a properly scientific context; but he extends his investigation of these concepts to questions of freedom and responsibility, and fate and astrology, and also the treatment of disease. Hankinson points out that causes and explanations are connected ideas: an explanation is the proffering of reasons, and this involves an account of causes; they are, nevertheless, different concepts—causes are actual items, events, agents, facts, states of affairs, whereas explanations are propositional. Hankinson isolates certain causal principles that recur throughout Greek philosophy: for instance, the principle of sufficient reason, the principle of causal synonymy, and the principle that nothing can come to be from nothing.