Sociology quickly evolved as an academic response to the perceived challenges of modernity , such as industrialization , urbanization , secularization , and the process of " rationalization ".  The field predominated in continental Europe , with British anthropology and statistics generally following on a separate trajectory. By the turn of the 20th century, however, many theorists were active in the English-speaking world . Few early sociologists were confined strictly to the subject, interacting also with economics , jurisprudence , psychology and philosophy , with theories being appropriated in a variety of different fields. Since its inception, sociological epistemology, methods, and frames of inquiry, have significantly expanded and diverged. 
To these may be added two other very important contributions of the 17th and 18th centuries, each of great theoretical significance. The first was the idea of structure. Having emerged in the writings of such philosophers as Thomas Hobbes , John Locke , and Jean-Jacques Rousseau with reference to the political structure of the state, it had spread by the mid-18th century to highlight the economic writings of the physiocrats and Adam Smith . The idea of structure can also be seen in certain works relating to human psychology and, at opposite reach, to the whole of civil society . The ideas of structure that were borrowed from both the physical and biological sciences were fundamental to the conceptions of political, economic, and social structure that took shape in the 17th and 18th centuries. And these conceptions of structure have in many instances, subject only to minor changes, endured in the contemporary study of social science.