"The assumption in this case is that human individuals are ontologically prior to society; in other words, human individuals are the basic constituents out of which social groups are composed. Logically if not empirically, human individuals could exist outside a social context; their essential characteristics, their needs and interests, their capacities and desires, are given independently of their social context and are not created or even fundamentally altered by that context. This metaphysical assumption is sometimes called abstract individualism because it conceives of human individuals from any social circumstances."
[WS:] I think it is an assumption of only a particular brand of individualism (or liberalism,) namely its Yankee (and to some extent British) variety.
However, it is possible to argue the exact opposite (as I believe the French sociologist Emile Durkheim does) - that all forms of human thought are created by society rather than individuals - without those socially "instilled" forms and concepts can barely be aware of their own individuality, let alone the abstract notion of freedom. Therefore, the notion of individual freedom itself as well as various forms of that freedom is really a product of a particular social organization, rather than "innate" or "natural" consciousness of the human individual.
In any case, discussing concepts like democracy or liberalism in abstraction does not make much sense to me. Ditto for concepts like "oppression" which I believe are interpretative schemata through which one sees the world, rather than empirical facts. You cannot argue with someone who adopts this interpretative schema, because it is not possible to empirically confirm or refute it - you either accept it or you do not, just like any other normative principle.
Wojtek