 Is it necessary to refer to internal constraints in order to make sense of the phenomena of oppression and structural injustice? Some might contest this view, or say that it is true only up to a point, for there are at least two reasons for thinking that the oppressed are lacking in negative liberty. First, while Berlin himself equated economic and social disadvantages with natural disabilities, claiming that neither represented constraints on negative liberty but only on personal abilities, many theorists of negative liberty disagree: if I lack the money to buy a jacket from a clothes shop, then any attempt on my part to carry away the jacket is likely to meet with preventive actions or punishment on the part of the shop keeper or the agents of the state. This is a case of interpersonal interference, not merely of personal inability. In the normal circumstances of a market economy, purchasing power is indeed a very reliable indicator of how far other people will stop you from doing certain things if you try. It is therefore strongly correlated with degrees of negative freedom (Cohen 1995, 2011; Waldron 1993; Carter 2007; Grant 2013). Thus, while the promotion of content-neutral positive liberty might imply the transfer of certain kinds of resources to members of disadvantaged groups, the same might be true of the promotion of negative liberty. Second, the negative concept of freedom can be applied directly to disadvantaged groups as well as to their individual members. Some social structures may be such as to tolerate the liberation of only a limited number of members of a given group. G.A. Cohen famously focused on the case proletarians who can escape their condition by successfully setting up a business of their own though a mixture of hard work and luck. In such cases, while each individual member of the disadvantaged group might be negatively free in the sense of being unprevented from choosing the path of liberation, the freedom of the individual is conditional on the unfreedom of the majority of the rest of the group, since not all can escape in this way. Each individual member of the class therefore partakes in a form of collective negative unfreedom (Cohen 1988, 2006; for discussion see Mason 1996; Hindricks 2008; Grant 2013; Schmidt 2020).