Side-Constraints

Side-constraints are anything that acts to confine or restrict. The focus here is on moral side-constraints. When we speak of moral side-constraints, we have an understanding of moral rights as requiring that nothing be done to prevent those rights being exercised. So, for example, conceived of in a side-constraint way, a right to freedom of speech requires that nothing should be done to prevent actions qualifying as an exercise in freedom of speech. In short, side-constraints are moral rights conceived of as bestowing an absolute right of noninterference in the exercise of a right.

It is a conception of moral rights that, although variously articulated earlier and elsewhere as part of a long tradition in thinking about rights, finds its definitive statement and first labeling as side-constraints in the work of Robert Nozick. There, the conception of rights as side-constraints is presented as the reason for acceptance of an “entitlement” theory of distributive justice. But it could equally well (as Nozick would probably concede) be viewed as a concept constructed to defend such a theory. Either way, conception and theory are intimately bound up together, and accordingly, it is side-constraints in the context of Nozick's theory of distributive justice that will be outlined here.

Nozick's theory of distributive justice is strongly libertarian, uncompromisingly free market orientated, and unflinchingly antiegalitarian. The notion of rights as side-constraints fits in with such an account by making it a violation of rights (specifically, a violation [Page 1923]of the right to liberty) to interfere with the workings of free markets to secure a more equal distribution than would otherwise prevail (or, indeed, any sort of predetermined pattern of distribution). The notion of rights as side-constraints does this by coming down on the traditionally free market liberal side of two longstanding disputes over the nature of rights.

First, and perhaps most fundamentally, by making rights absolute, the notion of rights as side-constraints requires rights to be viewed noninstrumentally as things of value in themselves rather than instrumentally as things of value only insofar as they serve a greater good of human welfare and the like. (Clearly, viewed instrumentally, rights could not be absolute, as they could be overridden by the demands of the greater good they are seen as serving.) Second, by understanding rights in terms of requiring others not to interfere in their exercise, the notion of rights as side-constraints understands them in a purely “negative” way as rights to noninterference and excludes from consideration what are contrastingly described as “positive rights,” involving a requirement to receive something of benefit from others. (In so doing, it fits in with a free market liberal perspective by excluding a right to welfare provision based on need.)

It follows that acceptance of a side-constraints interpretation of rights is only as good as the above two claims about the nature of rights. Insofar as Nozick offers a defense of those claims (here as elsewhere he cheerfully admits to inconclusiveness), it is by arguing that the alternative of an instrumental and/or positive conception of rights fails to respect the separateness of persons by treating people as a resource to be used by other people. (He presents this as a restatement of the Kantian principle that people should never be treated as means but only as ends.) Such a defense can, however, be questioned at just about any level. Most directly, there is the issue of whether respecting that separateness requires acceptance of the side-constraint interpretation of rights? (Not everyone taking a Kantian approach would agree it does.) In addition, there is the issue of the extent to which that separateness should be respected in the event of conflict with other moral demands: in particular, with the common good. Most fundamentally, there is the issue of the extent to which it should be respected at all. Surely, it can be argued, morality is all about enabling people to live together in collectively advantageous ways, and so the primary focus of moral attention is people as members of society rather than, as seems to be the case with talk of the separateness of persons, the individual in isolation?

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