Brian O'Shaughnessy puts forward a bold and original theory of consciousness, one of the most fascinating but puzzling aspects of human existence. Whatever mystery there may be about the origins of consciousness, O'Shaughnessy suggests that there is no mystery about what it is. He proceeds to give a philosophical elucidation of its nature, analysing it into purely psychological constituents. It is his contention that consciousness consists in a closely knit complex of occurrent mental phenomena and powers with thinking and self-knowledge at the centre--and nothing else. O'Shaughnessy's analysis accords a position of pre-eminence to the epistemological properties of consciousness. With this in mind he investigates the closely linked concepts of attention and perception alongside that of consciousness. He sets out an integrated theory of these three fundamental phenomena, demonstrating how close to the heart of consciousness is perception, envisaged already in the very concept. In effect he advances en passant a variant of empiricism which is based upon the nature of consciousness. A considerable part of the book is devoted to providing a theoretical account in these terms of those important senses through which the mind constitutes physical objects in space: above all, the highly developed sense of sight, but also the primordial body-senses, proprioception and touch, which underpin all else in the mind. In such ways concrete interaction between consciousness and the world is realized, and the epistemological basis of mind established. Consciousness and the World is a rich and exciting book, a major contribution to our understanding of the mind.