Cultures were supposed to grew from simple towards more complex and differentiated types. This is Evolutionism.
The argument as to whether civilization had evolved or had always existed with the primitives as miserable, sinful outcasts was not easily settled. The degeneration theory of savagery (that primitives regressed from the civilized state) had to be fought vigorously before social anthropology could progress. The social evolutionists countered the degenerationist views regarding primitivism as an indication of the fall from Grace.
Social evolutionism offered an alternative to the Christian/theological approach to understanding cultural diversity, and thus encountered more opposition. The new views presented evolution as a line of progression in which the lower stages were prerequisite to the upper. This idea countered old ideas about the relationships between God, mankind, and the nature of life and progress. Evolutionists criticized the Christian approach as requiring divine revelation to explain civilization.
Reactions within evolutionist thought:
There existed high rhetoric among the evolutionists, particularly concerning the most primitive stages of society. It was highly debated as to the order of primitive promiscuity, patriarchy, and matriarchy.
Reactions to evolutionism:
Karl Marx was struck by the parallels between Morgan’s evolutionism and his own theory of history. Marx and his co-worker, Friedrich Engels, devised a theory in which the institutions of monogamy, private property, and the state were assumed to be chiefly responsible for the exploitation of the working classes in modern industrialized societies. Marx and Engels extended Morgan’s evolutionary scheme to include a future stage of cultural evolution in which monogamy, private property, and the state would cease to exist and the “communism” of primitive society would once more come into being.
The beginning of the twentieth century brought the end of evolutionism’s reign in cultural anthropology. Its leading opponent was Franz Boas, whose main disagreement with the evolutionists involved their assumption that universal laws governed all human culture. Boas pointed out that these nineteenth-century individuals lacked sufficient data (as did Boas himself) to formulate many useful generalizations. Thus historicism (and later functionalism) were reactions to nineteenth century social evolutionism.
Leading Figures Johann Jacob Bachofen (1815-1887). Swiss lawyer and classicist who developed a theory of the evolution of kinship systems. He postulated that primitive promiscuity was first characterized by matriarchy and later by patrilineality. This later stage of patrilineality was developed in relation to Bachofen’s theory of the development of private property and the want of man to pass this on to their children. Bachofen’s postulation of a patrilianeal stage following a matrilineal stage was agreed upon by Morgan.