The doctrine of natural rights reached its largest degree of acceptance in England, France, and the United States. It was not only reflected in the thought of Thomas Jefferson but in the fundamental principles upon which the United States was established. It suffered an aberration in the form of the social contract theory which in its extreme forms was later repudiated. Its greatest weakness was the exaggerated form which it assumed, especially in England and the United States. In the latter country it became greatly magnified through contact with the spirit of discovery, invention, and pioneering which prevailed for over a century. Consequently, it dominated the thought life of the United States throughout the nineteenth century. It permitted captains of industry to exploit the helpless masses, and encouraged politicians to pursue selfish practices until governments became honeycombed with graft. It nearly capsized the good Ship of State--Democracy. Theories of natural rights have been supplanted by considerations of natural needs, both individual and social. Human needs are now considered the only imperatives, but even they are relative and changing. CHAPTER XII MALTHUS AND POPULATION CONCEPTS A unique and distinctive trend in social thought with important sociological implications developed in the closing years of the eighteenth century, namely, Malthusian thought regarding population. Malthusianism, however, was preceded by the ideas of William Godwin and Adam Smith. In 1775, Adam Smith had stated that “every species of animals naturally multiplies in proportion to the means of their subsistence, and no species can ever multiply beyond it.”[XII-1] Scanty subsistence, however, destroys a large percentage of offspring. Inasmuch as men, like all other animals, multiply naturally in proportion to the means of their subsistence, food is always, more or less, in demand; and food, or the cost of living, regulates population.[XII-2] City people must depend upon the country for their subsistence, whereas seaport towns can command food resources from all parts of the earth.