The conflict between rich and poor is typically seen in terms of the rich man's liberty against the poor man's well-being, where liberals favour the latter value and libertarians the former. It isn't commonly recognized that the liberty of the poor is also at stake here. But, as James P. Sterba argues (p.238):
What is at stake is the liberty of the poor not to be interfered with in taking from the surplus possessions of the rich what is necessary to satisfy their basic needs.
Needless to say, libertarians would want to deny that the poor have this liberty. But how could they justify such a denial? As this liberty of the poor has been specified, it is not a positive right to receive something, but a negative right of non-interference. Nor will it do for libertarians to appeal to a right to life or a right to property to rule out such a liberty because on the view under consideration liberty is basic and all other rights are derived from a right to liberty. Clearly what libertarians must do is recognize the existence of such a liberty and then claim that it conflicts with other liberties of the rich. But when libertarians see that this is the case, they are often genuinely surprised - one might even say rudely awakened - for they had not previously seen the conflict between the rich and the poor as a conflict of liberties.
Which liberty ought to win out is a topic for a future post. [Update: see here.] For now it is enough to upturn the common assumptions, and recognize that poverty is itself a form of unfreedom, and enforcing property laws is form of intervention. When you bar the starving man from taking a loaf of bread from your store, you are interfering with him. If he takes it anyway, and you call the police, then you are licensing state intervention to thwart the liberty of another individual. If negative liberty is our foundational value, then - as Sterba points out - one cannot rule out the prima facie importance of these liberties. We are going to have to carefully weigh the conflicting liberties against each other. The libertarian cannot just assume that the liberty of the propertied classes will come out on top. There is a genuine issue here, that the intellectually honest libertarian has to confront.
I have shown that poverty in a capitalist society involves exactly the sort of interference and lack of negative freedom that libertarians claim to abhor. But the commonplace rhetoric is so rarely challenged that it may be difficult to overcome one's deeply ingrained assumptions and recognize this brute fact. To help with this problem, Cohen (p.58) offers an illustration to help us see things in a new light:
[B]egin by imagining a society without money, in which courses of action available to people, courses they are free to follow without interference, are laid down by the law. The law says what each sort of person, or even each particular person, may and may not do without interference, and each person is issued with a set of tickets detailing what she is allowed to do. So I may have a ticket saying that I am free to plough this piece of land, another one saying that I am free to go to that opera, or to walk across that field, while you have different tickets, with different freedoms inscribed on them.
Imagine, now, that the structure of the options written on the tickets is more complex. Each ticket lays out a disjunction of conjunctions of courses of action that I may perform. I may do A and B and C and D OR B and C and D and E OR E and F and G and A, and so on. If I try to do something not licensed by my tickets or ticket, armed force intervenes.
By hypothesis, these tickets say what my freedoms (and, consequently, my unfreedoms) are. But a sum of money is nothing but a highly generalized form of such a ticket. A sum of money is a licence to perform a disjunction of conjunctions of actions - actions like, for example, visiting one's sister in Bristol, or taking home, and wearing, the sweater on the counter at Selfridge's.
Suppose that someone is too poor to visit her sister in Bristol. She cannot save, from week to week, enough to buy her way there. Then, as far as her freedom is concerned, this is equivalent to 'trip to Bristol' not being written on someone's ticket in the imagined non-monetary economy. The woman I have described has the capacity to go to Bristol. She can board the underground and approach the barrier which she must cross to reach the train. But she will be physically prevented from passing through it, or physically ejected from the train, or, in the other example, she will be physically stopped outside Selfridge's and the sweater will be removed. The only way that she will not be prevented from getting and using such things is by offering money for them.
Money provides freedom, and to lack money is to lack freedom. If the poor man tries to pursue his ends in life without the money to pay for them, then others will forcably interfere with him. The thief interferes with the liberty of rich to dispose of their holdings as they please; but likewise, the security guard interferes with the liberty of the thief to take from others' holdings as he pleases. This is a genuine clash of liberties, and it cannot be decided without appealing to some other, non-freedom, value (such as self-ownership).
That's the end of the negative-liberty-based argument. Of course, for the record, I must reassert the utter uselessness of negative (formal) liberty possessed in the absence of positive (substantive) capability. If you're stuck down a well, and I refuse to throw you a rope, you don't have any "freedom" worthy of the name. If everyone ignores you, consistently with perfect non-interference, that does not make you perfectly free. Unless you consider death to be perfect freedom, that is.
Cohen, G.A., Self-Ownership, Freedom, and Equality. Cambridge : Cambridge University Press, 1995.
Sterba, J.P., 'From Liberty to Welfare' in Ethics: The Big Questions. Malden, MA : Blackwell, 1998.