Historicism is an approach to explaining the existence of phenomena, especially social and cultural practices, by studying their history; that is, by studying the process by which they came about. The term is widely used in philosophy, anthropology, and sociology.
Thomas Cole, The Architect's Dream, 1840: an example of Historicism
G. W. F. Hegel (1770–1831)
Structural functionalism, or simply functionalism, is "a framework for building theory that sees society as a complex system whose parts work together to promote solidarity and stability".
Émile Durkheim
Herbert Spencer