New in paperback. Hardcover was published in 2018. Besides his famous graduate seminar, Robbins' most important and influential courses at LSE were the Principles of Economic Analysis, which he gave in the 1930s and again in the late 1940s and 1950s, as well as the History of Economic Thought, from 1953 until long after his official retirement. This book publishes for the first time the manuscript notes Robbins used for his lectures on the Principles of Economic Analysis from 1929/30 to 1934/40.