Plotinus (c. AD 205-270) can be regarded as the greatest Greek philosopher of late Antiquity, and as the father of Neoplatonism. His Enneads (`the nines') are now recognised as seminal works in the development of Western thought. This book is the only detailed scholarly commentary available on this part of Plotinus' work, and should be invaluable to all scholars interested in ancient philosophy and early Christian theology. All Greek in the commentary is translated.