Concentration, or the habit of local self-government, so strikingly illustrated in New-England, is next examined in contrast with centralization, as exhibited in England and France, and its admirable effects in tending to the maintenance of peace are fully exhibited. The various systems of colonization next pass in review, and give occasion for an examination of the various causes that brought negro slavery into this country, and the reason why it is here alone that the race has increased in numbers. India and Ireland, and the devastating effects of the colonial system, Annexation, and Civilization, furnish the materials for the succeeding chapters, and give occasion--the last particularly--for the expression of opinions much at variance with those taught by Guizot and others of the most distinguished men of our day. Such are the Past and Present. The closing chapter is the Future, and contains an examination of many remarkable facts now presented to our view by our own country, produced by the existence of the unnatural system fastened upon the world by England, and to be remedied by the adoption of an American policy, having for its object that of enabling men to live together and combine their exertions, instead of flying from each other, leaving behind rich lands uncultivated, and going to Texas or Oregon to begin the work of cultivation on the poorer ones. "With each step in the progress of concentration his physical condition would improve, because he would cultivate more fertile lands, and obtain increased power over the treasures of the earth. His moral condition would improve, because he would have greater inducements to steady and regular labor, and the reward of good conduct would steadily increase. His intellectual condition would improve, because he would have more leisure for study, and more power to mix with his fellow-men at home or abroad; to learn what they knew, and to see what they possessed; while the reward of talent would steadily increase, and that of mere brute wealth would steadily decline. His political condition would improve, because he would acquire an increased power over the application of his labor and of its proceeds. He would be less governed, better governed, and more cheaply governed, and all because more perfectly self-governed." The field surveyed by Mr. Carey in the _Past and Present_ is a broad one--broader than that of any other book of our time--for it discusses every interest of man. The ideas are original--whether true or not, they are both new and bold. They are based upon a great law of Nature, and it is the first time that any system of political economy has been offered to the world that was so based. The consequence is, that all the facts place themselves, as completely as did the planets when Copernicus had satisfied himself that the earth revolved around the sun.[29]