Simmel was one of the first generation of German sociologists: his neo-Kantian approach laid the foundations for sociological antipositivism, asking 'What is society?' in a direct allusion to Kant's question 'What is nature?',^[2] presenting pioneering analyses of social individuality and fragmentation. For Simmel, culture referred to "the cultivation of individuals through the agency of external forms which have been objectified in the course of history".^[2] Simmel discussed social and cultural phenomena in terms of "forms" and "contents" with a transient relationship; form becoming content, and vice versa, dependent on the context. In this sense he was a forerunner to structuralist styles of reasoning in the social sciences. With his work on the metropolis, Simmel was a precursor of urban sociology, symbolic interactionism and social network analysis.^[3][4]

An acquaintance of Max Weber, Simmel wrote on the topic of personal character in a manner reminiscent of the sociological 'ideal type'. He broadly rejected academic standards, however, philosophically covering topics such as emotion and romantic love. Both Simmel and Weber's nonpositivist theory would inform the eclectic critical theory of the Frankfurt School.^{[5] (Source: Wikipedia)}

Ferdinand Tönnies (German: [ˈtœniːs]; 26 July 1855 – 9 April 1936) was a German sociologist and philosopher. He was a major contributor to sociological theoryand field studies, best known for his distinction between two types of social groups, Gemeinschaft and Gesellschaft. He co-founded the German Society for Sociology, of which he was president from 1909 to 1933, after which he was ousted for having criticized the Nazis. Tönnies was considered the first German sociologist proper,^[1] published over 900 works and contributed to many areas of sociology and philosophy. (Source: Wikipedia)

David Émile Durkheim (French: [emil dyʁkɛm] or [dyʁkajm];^[1] April 15, 1858 – November 15, 1917) was a French sociologist. He formally established the academic discipline and—with Karl Marx and Max Weber—is commonly cited as the principal architect of modern social science.^[2][3]

Much of Durkheim's work was concerned with how societies could maintain their integrity and coherence in modernity; an era in which traditional social and religious ties are no longer assumed, and in which new social institutions have come into being. His first major sociological work was The Division of Labour in Society (1893). In 1895, he published The Rules of Sociological Method and set up the first European department of sociology, becoming France's first professor of sociology.^[4] In 1898, he established the journal L'Année Sociologique. Durkheim's seminal monograph, Suicide (1897), a study of suicide rates in Catholic and Protestant populations, pioneered modern social research and served to distinguish social science from psychology and political philosophy. The Elementary Forms of the Religious Life (1912) presented a theory of religion, comparing the social and cultural lives of aboriginal and modern societies.

Durkheim was also deeply preoccupied with the acceptance of sociology as a legitimate science. He refined the positivism originally set forth by Auguste Comte, promoting what could be considered as a form of epistemological realism, as well as the use of the hypothetico-deductive model in social science. For him, sociology was the science of institutions, if this term is understood in its broader meaning as "beliefs and modes of behaviour instituted by the collectivity"^[5] and its aim being to discover structural social facts. Durkheim was a major proponent of structural functionalism, a foundational perspective in both sociology and anthropology. In his view, social science should be purely holistic;^[6] that is, sociology should study phenomena attributed to society at large, rather than being limited to the specific actions of individuals. (Source: Wikipedia)