Thursday, July 19, 2012

On modal logic and rights

There's been a lively discussion up on my Facebook wall for a while now. For those of you not in that loop, I've got an old friend, Joe, who holds and brandishes a clear and pure stripe of libertarian political and moral thinking, and will on occasion brandish it in comments on my wall. We used to do it in person, back when we both taught incorrigible youngsters how to disrespect their betters elders and I helped him figure out what the hell an integral domain is.

The current discussion centers on rights. The positions, roughly stated, stand as follows:

Everyone pretty well agrees that there is a sense, which I've been calling the statutory sense, in which rights are given/controlled/created/overseen by the state. In this sense, a statement such as "X has the right to T" or "X has the right to do A" means, definitionally, that the state does not claim to have the power to prevent X's having of T or doing of A; or often, that X must be provided with T through some mechanism the state sets up. (Ideally, what the state claims to not have the power to do is also a reality, but this sense of "right" is already quite an exercise in nominalisms, so I won't dig further in that direction.) A key fact here is that the state both can and frequently does deny rights-in-the-statutory-sense to people, and unabashedly so, even when those people vehemently claim that what is being denied to them is something they have a right to.

Clearly, what such a person means when they say that they, for example, have the right to carry a weapon at all times, or that they have the right to a free-tuition public education through the baccalaureate level, is then not this statutory sense, because neither of these named actions or goods is provided for by statute or recognized by the courts. (I don't want to get into the matter of branches and separation of powers here either.) Instead, I think it's pretty well agreed by everyone who's commented, that a claim like these is a moral claim. The differences start appearing when we start clarifying the detailed content of these claims.

I don't deny that I am at my most comfortable when making claims as formalizable as possible. (This may color my thinking, but I think it does leave me with fewer irreducible propositions.) So when I need to clarify a moral claim, my first instinct is to apply the tools of modal logic and use the standard deontic/modal \( \square \) and \( \diamond \) formulations. If \( \varphi \) is a factual proposition like "Heelfilcher drinks beer" or "the state prohibits X from voting", then \( \square \varphi  \) is the statement that "It is obligatory that Heelfilcher drink beer", and \( \diamond \varphi \) is the statement "it is licit for the state to prohibit X from voting". (Textbooks frequently say "it is permissible" rather than "it is licit", but I don't like the imagery of someone giving "permission". Of course "licit" has its own problems, since etymologically it conjures up a legislator.) We have the following equivalences: \[ \square \varphi \equiv \neg \diamond \neg \varphi \qquad \diamond \varphi \equiv \neg \square \neg \varphi \]since it is morally obligatory to do an action iff it is illicit to omit that action, etc.

What does this mean? Well, among other things, it means that when I (i.e. me, speaking for myself) want to clarify a moral claim, I start by identifying actions (to be represented by statements with no modal operators, i.e. no claims about their (il)licitness or obligatory character), and then try to say what I'd like to about their morality with as little modality as possible. In fact, this interpretation of the modal operators is problematic in that it's not clear (at least initially) what a modal nesting of depth greater than 1 would mean. (Here \[ \text{Heelfilcher drinks beer} \]has modal depth zero, \[ \square ( \text{Heelfilcher drinks beer} ) \]depth one, and \[ \square \left( \square ( \text{Heelfilcher drinks beer} ) \right) \]depth two. The statements of depth zero and one have clear interpretations, as I've indicated above, and in an abstract Kripke semantics so does the one of depth two; but damned if I can make it make much sense in an actual context of moral philosophizing.)

One of the nice features of this, for me, is that it is a theorem of pure logic that no set of statements of fact ("such-and-such-is-the-case" or "X performs action A") can ever imply a statement of modality, unless that modal statement is tautologically true. This is encapsulated in an old maxim, sometimes attributed to Hume, to the effect that simply telling me what the state of the world is has no bearing at all on how the world ought to be.

Or in English, if  you want to argue that something is right or wrong, if you want to argue that something is obligatory or illicit or permissible, then you cannot simply argue from empirical premises about the world around us. If I want to convince you of a moral claim, the argument must begin at shared moral premises.

I haven't told you what I mean by "X has the right to do A", have I? Well take a guess. Have you guessed? OK. Here's my answer. "X has the right to do A" means, definitionally (to me), that it is illicit for X to be prevented from doing A by the power vested in agents by the society X lives in. At the bare minimum, this means the state; but societal coercion is exercised by more than just the institutions of the state.

And how do we go about deciding the truth of such a statement? How are we to determine whether an exercise of government power is wronging someone under that government's power?

To tell the truth, I don't have a complete theory there. That's ok, academic careers in moral philosophy are made by advancing more or less comprehensive theories of things like state power -- apparently the field is still staggering about holding their ears from the whelming overtones of the great bell rung by Rawls -- and I'd be happy to come up with a reasonably simple and not-too-outre thought-experiment that clarifies some of the core disagreements between someone like Joe and myself. (By "clarify", I mean "swings one or more party's general position, so that the positions are less in conflict".)

You see, Joe's position is that "X has the right to T" means, definitionally, that were X the only person in existence, then X would have T; "X has the right to do A" means definitionally, that were X the last person on earth then X would have the right to do A. The second is formally circular; I've asked Joe to expand on his ideas, but I don't feel comfortable paraphrasing them yet any further than this. The first, on the other hand, is meaningful. (And clearly wrong, I might add -- the last person on earth might not in fact possess any steel tools, but who would claim that s/he does not have the right to all the steel tools s/he could amass?) And I contend that it falls afoul of my observation about modal implication above: the hypothesis is supposed to be that a (counterfactual, but that's irrelevant) person possesses some thing. This is a modal-depth-zero claim, and if the statement "X has a right to T" is to have any moral meaning above that of an empirical claim, it can't be equivalent to such a statement.

I had meant for this post to be a parable illustrating that Joe's definitions don't accord with commonly held moral intuitions. (I said in the Facebook discussion that his definition is frankly bizarre; I'm sticking to that story, no matter how many Ayn Rand quotes he summons up in support). It appears that the introductory material has swallowed that post, so I'll try this again tomorrow.

(Note: yes, I have been incredibly lazy while writing this post and haven't included links. I mean to clean that up some, but if you think one is in order somewhere, post a comment indicating where and I'll strongly consider including it.)

This post has been brought to you via the generous sponsorship of 21st Amendment Brewery's Back in Black IPA.


  1. I've never posted on a blog before so don't sue me if I mess it up. Only one small point of clarification at this point. I would not claim that "X has a right to T" is a right of the last person on earth or a right in general. If A is the action of finding T and figuring out how to get it home OR figuring out how to manufacture T from a bunch of other T's THEN "X has a right to do A" implies that X could obtain T if he is willing to put forth the effort but certainly does not imply that X has a right to T because if X has a right to T then X would not have to do anything to obtain T and T would be provided.

    This is the essence of the last man on earth scenario for clarification of rights. If I were the last man on earth I would not have a right to coconuts. I would have the right to go out and gather all the coconuts I want but none will fall into my lap (assuming I am not sitting under a coconut tree when one decides to dislodge itself). It clarifies, in my prematurely addled brain, that rights can only be rights to action as in the Jefferson quote. Of course rights in this scenario have little meaning but they do clarify what a right is. If others have the same rights and we are not allowed to infringe on the rights of others (insuring this is a valid function of the state as I see it) then my conception of rights is at least very similar to Jefferson's and Rand's. This is no surprise to anybody who knows me. I understand the concept of logic but get lost in it's rigid application. It is my hope that the clarification I have provided in this post along with Matthew's deft guidance will lead us to.......something of use?

  2. If you want to limit the discussion to statements "X has the right to perform action A", I'm cool with that. As I wrote above, I'm not sure I understand your criterion for actions yet, since the way you phrased it in the facebook discussion was maybe in a hurry, and I'm not sure how to make it non-circular. I do like this idea of talking about the right to go out and gather coconuts, or the right to take what one already has and produce something with it, or what have you. (In this formulation, the right to a thing becomes transformed into the right to maintain possession of that thing, which emphasizes the active character of possession; it raises the question, can one rightly come to possess something, and then subsequently become in the wrong to possess it without having done anything? I think that particular question isn't too germane to this discussion, but I don't think the answer is obviously no. (I'm not including trivial examples like lending here, since the "possession" there is of the stewardship variety rather than ownership.)

    In any case: you don't need to muck about in the formal logic here Buzz, but it would be really helpful if you could lay out, without using the term "right", what it means to you to state that someone (even possibly the last person on earth) has the right to perform some action. In the post, I take "it is (morally) obligatory to" and "it is (morally) licit to" as basic (undefined) terms. (If I say something is right or wrong, I'm intending some shorthand for these.) If you'd like to propose others in addition to or in competition with these basic terms, let's hear them. Basic terms should, among other things, be such that all parties to the discussion agree about how they work. (We may not agree whether some action is obligatory, but I think we agree on what it means for an action to be obligatory.) For this reason, I'm unwilling to allow rights as a basic notion.

  3. It is morally obligatory to act in accordance with one's will. It is morally licit to act in a way that prevents others from acting in accordance with their will. This would be a (probably linguistically and logically flawed) basic starting point. As for ownership of stuff I would suggest that we don't discuss it for as long as possible. However, it will become necessary sooner rather than later.