For the next advance, we must again look to England. Passing by McCulloch(42) and Senior, a gifted writer, the legitimate successor of Ricardo is John Stuart Mill.(43) His father, James Mill,(44) introduced him into a circle of able men, of which Bentham was the ablest, although his father undoubtedly exercised the chief influence over his training. While yet but twenty-three, in his first book, “Essays on some Unsettled Questions of Political Economy” (1829-1830), he gained a high position as an economist. In one form or another, all his additions to the study are to be found here in a matured condition. The views on productive and unproductive consumption, profits, economic methods, and especially his very clever investigation on international values, were there presented. His “Logic” (1843) contains (Book VI) a careful statement of the relation of political economy to other sciences, and of the proper economic method to be adopted in investigations. Through his “Principles of Political Economy” (1848) he has exercised a remarkable influence upon men in all lands; not so much because of great originality, since, in truth, he only put Ricardo’s principles in better and more attractive form, but chiefly by a method of systematic treatment more lucid and practical than had been hitherto reached, by improving vastly beyond the dry treatises of his predecessors (including Ricardo, who was concise and dull), by infusing a human element into his aims, and by illustrations and practical applications. Even yet, however, some parts of his book show the tendency to too great a fondness for abstract statement, induced probably by a dislike to slighting his reasons (due to his early training), and by the limits of his book, which obliged him to omit many possible illustrations. With a deep sympathy for the laboring-classes, he was tempted into the field of sociology in this book, although he saw distinctly that political economy was but one of the sciences, a knowledge of which was necessary to a legislator in reaching a decision upon social questions. Mill shows an advance beyond Ricardo in this treatise, by giving the study a more practical direction. Although it is usual to credit Mill with originating the laws of international values, yet they are but a development of Ricardo’s doctrine of international trade, and Mill’s discussions of the progress of society toward the stationary state were also hinted at, although obscurely, by Ricardo. In the volumes of Mr. Mill the subject is developed as symmetrically as a proof in geometry. While he held strongly to free trade,(45) he gave little space to the subject in his book. All in all, his book yet remains the best systematic treatise in the English language, although much has been done since his day.(46)