In Marx’s 1844 manuscripts, alienation concerns people confronting their products, activity, human possibilities, and relations with others as external powers. The argument is situated within wage labour and private property, rather than being a synonym for loneliness or unhappiness.
The worker’s product objectifies their activity yet confronts them under another’s ownership and control. Activity itself can become an imposed means of subsistence instead of a realization of life. Objectification and alienation therefore are not identical.
The discussion of species-being concerns the possibility of shared, conscious, transformative activity. Its relation to an account of human nature and its continuity with later writings remain interpretive questions. Neither an unbroken continuity nor an absolute rupture between the manuscripts and Capital should be presumed.
Reification and commodity fetishism are connected but distinct analytical tools. Contemporary uses should specify relations such as control over work, ownership, and cooperation, rather than turn alienation into an indefinite name for every dissatisfaction.