I am normally said to be free to the degree to which no man or body of men interferes with my activity. Political liberty in this sense is simply the area within which a man can act unobstructed by others. If I am prevented by others from doing what I could otherwise do, I am to that degree unfree; and if this area is contracted by other men beyond a certain minimum, I can be described as being coerced, or, it may be, enslaved. Coercion is not, however, a term that covers every form of inability.
If I say that I am unable to jump more than ten feet in the air, or cannot read because I am blind, or cannot understand the darker pages of Hegel, it would be eccentric to say that I am to that degree enslaved or coerced. Coercion implies the deliberate interference of other human beings within the area in which I could otherwise act. You lack political liberty or freedom only if you are prevented from attaining a goal by human beings. Mere incapacity to attain a goal is not lack of political freedom. This is brought out by the use of such modern expressions as `economic freedom' and its counterpart, `economic slavery'.
It is argued, very plausibly, that if a man is too poor to afford something on which there is no legal ban--a loaf of bread, a journey round the world, recourse to the law courts--he is as little free to have it as he would be if it were forbidden him by law. If my poverty were, a kind of disease, which prevented me from buying bread, or paying for the journey round the world or getting my case heard, as lameness prevents me from running, this inability would not naturally be described as a lack of freedom, least of all political freedom. It is only because I believe that my inability to get a given thing is due to the fact that other human beings have made arrangements whereby I am, whereas others are not, prevented from having enough money with which to pay for it, that I think myself a victim of coercion or slavery.
In other words, this use of the term depends on a particular social and economic theory about the causes of my poverty or weakness. If my lack of material means is due to my lack of mental or physical capacity, then I begin to speak of being deprived of freedom (and not simply about poverty) only if I accept the theory. If, in addition, I believe that I am being kept in want by a specific arrangement which I consider unjust or unfair, I speak of economic slavery or oppression. `The nature of things does not madden us, only ill will does', said Rousseau. The criterion of oppression is the part that I believe to be played by other human beings, directly or indirectly, with or without the intention of doing so, in frustrating my wishes. By being free in this sense I mean not being interfered with by others. The wider the area of noninterference the wider my freedom.
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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. I wish to be a subject, not an object; to be moved by reasons, by conscious purposes, which are my own, not by causes which affect me, as it were, from outside. I wish to be somebody, not nobody; a doer--deciding, not being decided for, self-directed and not acted upon by external nature or by other men as if I were a thing, or an animal, or a slave incapable of playing a human role, that is, of conceiving goals and policies of my own and realizing them. This is at least part of what I mean when I say that I am rational, and that it is my reason that distinguishes me as a human being from the rest of the world. I wish, above all, to conscious of myself as a thinking, willing, active being, bearing responsibility for my choices and able to explain them by references to my own ideas and purposes. I feel free to the degree that I believe this to be true, and enslaved to the degree that I am made to realize that it is not.
The freedom which consists in being one's own master, and the freedom which consists in not being prevented from choosing as I do by other men, may, on the face of it, seem concepts at no great logical distance from each other--no more than negative and positive ways of saying much the same thing. Yet the `positive' and `negative' notions of freedom historically developed in divergent directions not always by logically reputable steps, until, in the end, they came into direct conflict with each other. One way of making this clear is in terms of the independent momentum which the, initially perhaps quite harmless, metaphor of self-mastery acquired. `I am my own master'; `l am slave to no man'; but may I not (as Platonists or Hegelians tend to say) be a slave to nature? Or to my own `unbridled' passions? Are these not so many species of the identical genus `slave'--some political or legal, others moral or spiritual?
Have not men had the experience of liberating themselves from spiritual slavery, Or slavery to nature, and do they not in the course of it become aware, on the one hand, of a self which dominates; and, on the other, of something in them which is brought to heel? This dominant self is then variously identified with reason, with my `higher nature', with the self which calculates and aims at what will satisfy it in the long run, with my `real', or `ideal', or `autonomous self, or with my self `at its best'; which is then contrasted with irrational impulse, uncontrolled desires, my `lower' nature, the pursuit of immediate pleasures, my `empirical' or `heteronomous' self, swept by every gust of desire and passion, needing to be rigidly disciplined if it is ever to rise to the full height of its `real' nature. Presently the two selves may be represented as divided by an even larger gap: the real self may be conceived as something wider than the individual (as the term is normally understood), as a social `whole' of which the individual. is an element or aspect: a tribe, a race, a church; a state, the great society of the living and the dead and the yet unborn.
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Isaiah Berlin, two concepts of Liberty