How does God think? How, ideally, does a human mind function? Must a gap remain between these two paradigms of rationality? Such questions exercised the greatest ancient philosophers, including those featured in this book: Socrates, Plato, Aristotle, the Stoics and Plotinus. This volume encompasses a series of studies by leading scholars, revisiting key moments of ancient philosophy and highlighting the theme of human and divine rationality in both moral and cognitive psychology. It is a tribute to Professor A. A. Long, and reflects multiple themes of his own work.