BV: We should distinguish between weaker and stronger versions of the principle:
P1. If x has a right to y, and if z is a means of achieving y, then x has a right to seek to acquire z.
P2. If x has a right to y, and if z is a means of achieving y, then x has a right to be given z.
(1) I have a right to life and security of my person. (2) If I have a right to life and security of my person, then I have a right to the means whereby these rights may be secured and protected. (3) Guns may be used to secure and protect my right to life and security of my person. (4) Therefore, I have a right to own a gun.
BV: On 10 November 2009 I gave a more careful detailed argument along the same lines. See Deriving Gun Rights from the Right to Life.
This seems to me very plausible, but of course (2) relies on the controversial principle identified above.
BV: I would say that the argument relies on (P1) but not (P2).
In similar fashion, any argument for the claim that each of us has a right to health care will probably have to rely on a similar premise. I can imagine an argument going something like this:
(1) I have a right to life and security of my person. (2) If I have a right to life and security of my person, then I have a right to the means whereby these rights may be secured and protected. (3) Affordable health care may be used to secure and protect my right to life and security of my person. (4) Therefore, I have a right to affordable health care.
As before, premise (2) relies on the controversial principle identified earlier. And, as you point out in your post, similar arguments could be run to establish that each of us has a right to food, shelter, and clothing.
BV: But again, all one needs is the weaker principle, (P1). If I have a right to life, then I have a right to sustain my life. A necessary means to that end is food. So I have a right to food. But all that means is that I have a right to seek to acquire food (by hunting, fishing, foraging, growing, buying, bartering, begging, etc.) It does not mean that I have a right to be supplied with food by others. I have no positive right to be fed. What I have is a negative right not to be impeded in my quest for food and other vital necessities. (Adults are under discussion, not young children.)
Here, then, is my question: what ought we to think about the controversial principle?
BV: The first thing we should think about it is that it is ambiguous as between (P1) and (P2). I would say that (P1) is very plausible if not obviously true. But it needs qualification. Do I have a right to biological or chemical weapons? I have the right to repel a home invasion using a shotgun, but presumably not the right to repel such an invasion using biological agents that are likely to spread throughout the neighborhood. So consider
P1*. If x has a (negative) right to y, and z is a minimally efficacious means of achieving y,then x has a (negative) right to acquire z.
By 'minimally efficacious' I mean a means to an end that is an efficient and effective means to the end in view but not so powerful or extensive as to bring with it negative consequences for others. My right to buy food would then not be a right to buy all the food in the supermarket. My right to repel home invaders does not translate into a right to lay waste to the entire neighborhood in so doing. No doubt further refinements are needed, but (P1) strikes me as on the right track.
Although I am inclined to think that the principle is false, what is of interest to me is a more troublesome question. Any false general claim may have true instances. Are there true instances of this false general principle? How do we go about deciding which instances of the principle are true and which not? Can the principle be used to establish gun rights but not rights to health care or food/shelter/clothing?
BV: I should think that guns and butter are on a par. More fully, guns, food, shelter, clothing, certain medicines, bandages, certain medical appliances, e. g. sphygmomanometers for the hypertense, etc. are all on a par. Given that I have the natural negative right to life, then surely I have the right to pursue and acquire those things that I need to defend and sustain my life. What I don't have is the positive right to be given them by others or by the government, especially given the fact that the government produces no wealth but gets its wealth by coercive taking. (Not that I am opposed to governmental coercion, within limits. There simply cannot be a government that is not coercive. I am very pleased that the government has forced Bernie Madoff into prison, thereby doing to him what it would be a crime for me to do to him.)
So I don't think my gun argument suffers from probative overkill, 'proving too much.' The pattern of argument extends to food, shelter, and clothing, etc. But contemporary liberals are in the same boat: their pattern of argument extends to food, shelter, clothing, etc. But their extension does amount to probative overkill and a reductio ad absurdum of their original argument. If there is a positive right to health care services and health insurance (these are of course not the same), then a fortiori, there is a positive right to food, shelter, and clothing. But this is absurd, ergo, etc.