In Roman law, alienatio meant the transfer of property to a stranger.
The Latin word alienus meant belonging to another. From it came alienatio, a legal term for transferring property rights, particularly in land.1 In English by the early fifteenth century, alienation carried three distinct meanings: estrangement from God, transfer of ownership, and mental derangement.2
The psychiatric connection survived into the nineteenth century. Doctors who treated the mentally ill were called alienists, specialists in the condition of being separated from one's own mind.
The philosophical transformation began with Hegel. In his Phenomenology of Spirit (1807), he used Entfremdung (estrangement) and Entäusserung (externalization) to describe a process in which the human spirit became separated from itself through its own activity.3
Karl Marx grounded the abstraction in the factory. In his Economic and Philosophic Manuscripts of 1844, he identified four dimensions of alienated labor: workers estranged from the product, from the act of production, from their human nature, and from other people.4
Marx's manuscripts were not published until 1932, nearly fifty years after his death. When they appeared, the concept reshaped twentieth-century social theory. Existentialists, sociologists, and psychologists all adopted the term.
The French physician Philippe Pinel had used alienation mentale to describe patients disturbed by emotional states and social conditions without having entirely lost their reason.5 A word from Roman property law passed through medieval theology, eighteenth-century psychiatry, and Hegelian philosophy before Marx applied it to the assembly line.