Complex sentence: Keynes observes that this is a precursor to his theory of effective demand; he notes the book describes the paradox of thrift: showing that a community which forsakes luxury for savings achieves neither.
Split into simpler sentences: Keynes observes that this is a precursor to his theory of effective demand. He notes that the book describes the paradox of thrift--showing that a community that forsakes luxury for savings achieves neither.