How can human coexistence be explained? The Paper App provides a brief introduction to sociological thinking. In addition to the traditionally contrasted major directions of holism and individualism, there has always been another - relationism. After a concise introduction to the subject, the context of its emergence, and the methods of sociology, it is demonstrated how three classics of the field (Durkheim, Weber, Simmel) have outlined the three logically possible fundamental perspectives on social coexistence among humans. The resulting three fundamental directions of sociological theory (objectivism, subjectivism, relationism) are explained with further examples from the history of theory. Finally, these three perspectives on the social are examined for their practical applicability.