Presocratic Philosophy: A Very Short Introduction explores the puzzles sketched out by the Presocratic philosophers: What is being? Suppose what is real is very different from what we seem to see and hear: what then? And if we can ever discover the truth about what exists, how exactly could we prove it? These questions grew out of a primitive interest in cosmology, but they have led directly into metaphysics, theory of knowledge, philosophy of language, logic, and many other branches of philosophy as we know it now. Moreover, these pioneering questions about knowledge, reality, and truth, were often accompanied by new insights into mathematics, astronomy, physics, politics, religion, and morality.