In the following pages we shall meet a remarkable group of thinkers who faced many of the main issues that concern humanity, and developed the discipline of philosophy as a way of clarifying and understanding them. Where only fragments and summaries survive, the conclusions are elusive, and discussions of the original views are still open-ended. On the other hand, even where there is a considerable body of original texts available, as is the case with Plato and Aristotle, although they have been subject to centuries of interpretation, analysis and commentary, their core meanings remain debatable. We can therefore join the Greeks in their exploration of perennial issues not in the spirit of reading history but more in the expectation of meeting ideas that are worth further investigation. These philosophers challenged their predecessors and competed with each other in the quest for solutions, and we too can, as it were, sit down with them and discuss the same problems. With Greek plays, successive generations have found ways of interpreting the tragedies that throw new light on their dramatic developments. Watching a modern-dress Oedipus, in an English translation, can be a gripping and emotional experience. Similarly with philosophy: despite the unfamiliar background and the language differences there can still be engagement with the issues involved. A serious study of Greek philosophy is in itself a philosophical exercise, demanding but rewarding.