The distinction between negative and positive freedom stems from the liberal philosopher, Isaiah Berlin's 1958 inaugural address at Oxford University entitled 'Two Concepts of Liberty', in which he treats 'liberty' and 'freedom' as synonyms. On "the notion of negative freedom", Berlin states, "I am normally said to be free to the degree to which no man or body of men interferes with my activity." On the other hand, "the 'positive' sense of the word 'liberty' derives from the wish on the part of the individual to be his own master. I wish my life and decisions to depend on myself, not on external forces of whatever kind. I wish to be the instrument of my own, not of other men's, acts of will." This positive notion of freedom is summed up in the word "self-mastery". Note that both these notions are of individual freedom of an individual subject with its own will vis-à-vis an objective world of other things and, especially, other persons. There is thus a dichotomy between individual and society.
In contemporary discussion of negative and positive freedom, the latter "has often been thought of as necessarily achieved through a collectivity" (SEP). This opens the way to the individual's will being trumped by and subsumed under an effective collective will that is able to realize a collective aim through the appropriate social institutions, mainly the state, its organs and agencies. In particular, positive freedom collectivized is congruous with the welfare state, but also with other totalitarian and authoritarian regimes in the name of some version of the social good. As a liberal, Berlin warns against (social-)totalitarian interpretations of positive freedom in which, say, a "true self" or a "rational self" is posited to trump the merely empirical individual self with its desires and passions. In this connection he quotes the illiberal German, Fichte, e.g.: "'No one has ... rights against reason.' 'Man is afraid of subordinating his subjectivity to the laws of reason. He prefers tradition or arbitrariness.’"
Yet in all this exposition, Berlin does not make the essential connection between freedom and power, even though the word 'power' occurs in his speech several times, mainly in the footnotes. Similarly, the SEP also does not discuss the intimacy between freedom and power. The closest it comes is the notion of "republican freedom", which "can be thought of as a kind of status: to be a free person is to enjoy the rights and privileges attached to the status of republican citizenship", so that your negative freedom not to be interfered with is supplemented and reinforced by a republican political power.
The flaw in this kind of analytic thinking is that freedom is on the one side and power on the other, just as the individual is on one side and society or government on the other. Both of these schemata are fallacious. Why? Because both freedom and power, individual and society are each two sides of their own respective coins, and the two coins themselves are interlinked.
Freedom relates to the movement of human life. Each single human being is an origin or source of power for its own life-movements out of the ultimate fathomlessness of its own volition. The actualization of power is life-movement itself toward some self-posited end, whether it be good or bad. This is the lesson of the Aristotelean ontology of power with its famous triad of key concepts, du/namij, e)ne/rgeia and e)ntele/xeia. The notion of individual negative freedom is that there is no obstacle to your actualizing your potential, i.e. your power to initiate some sort of life-movement toward a goal. The movement is without resistance, at least from others. The individual is in splendid isolation, pre-social or asocial. Such pre-sociality corresponds to those Rousseauian types of socio-political theory that proceed naively from some imagined state of nature consisting of a scattered bunch of isolated individuals which, in turn, is associated with the childish notion of individual (negative) freedom as being able to do what you like. This notion of freedom is rightly criticized by Hegel as caprice (Willkür), however, without his criticizing the very notion of the abstractly free individual (abstraktes Recht) that corresponds to the phantasy of a state of nature.
Rather than imagining a resistanceless freedom, it must be admitted to view that i) the individual is always already sharing the world with others and ii) individuality itself is a mode of sociation. It seems that not only liberal thinking, but all stripes of political thinking, left, right and centre, have missed both these points by not paying attention to the ontology of (social) power itself. And this despite (or rather: because of) the recent fashionability of shallowly talking about 'social ontologies' without knowing what ontology means.
Re i): individual freedom is at core neither negative nor positive but both in the sense that it is an exercise of individual power in a power play with others (a kind of sociating movement), and hence of itself comes up against the resistance of other individual and collective, i.e. bundled individual, powers. Negative freedom is associated more with du/namij, i.e. potentiality, whereas positive freedom is associated more with e)ntele/xeia, i.e. actualization in perfected presence; hence the one-sidedness of both notions. If this power play is to be free, it must be fair in the sense that you have a fair chance of achieving your ends without the power play being rigged against you from the start. Since you are always already sharing a world with others, who are likewise exercising their individual powers, the fairness of power play depends upon a superior political instance to guarantee fair rules of power play without, however, guaranteeing particular outcomes (achieved ends), i.e. the what-you-have-in-the-end of e)ntele/xeia. Hence freedom is intimately coupled with fairness conceived as the beauty of power play among people, but you don't always get what you want.
Re ii): the individual itself is only a particular historical mode of sociation first enabled by the social power of reified value which serves as the medium of sociation for the power plays of individual freedom. Neither liberals nor Marxists nor other leftists nor conservatives get this. On markets of all kinds, individuals engage in power plays mediated in particular by the reified value-form of money. Apart from being a reified power for acquiring personal consumption goods and services, this money also may be a particular value-form of capital in its circuit through its various value-form stages of money-capital, productive capital and circulation capital. It is precisely reified value in the form of money, purchased commodities and acquired land that enables the modern individual to actually be (presence as) an individual with a private world not interfered with by others, including the government. By virtue of the income you receive and the wealth you have accumulated, you are then free to do what you like with it within a realm of privacy guaranteed by the political power of government. Likewise, and conversely, you are individually free to engage in power plays to gain income, in particular, by hiring out your personal powers and abilities. With any other mode of (non-reified) sociation, you would not have this risky freedom of singularity, but would have to negotiate (perhaps even each instance of) your exercise of practical free will with others (e.g. a State bureaucracy, a council or committee of some sort, a public meeting, etc.). The reified power play would become a political power play with entirely different rules of play, and the individual as such, along with its freedom, would cease to exist, i.e. to presence in the historical world of an historical age.
Further reading: 'Social Power and Government' excerpted from my Social Ontology. See also here Commutative and distributive justice and Potentiality and Actuality.