42 Kevin Schieman

https://www.existenz.us Volume 17, No. 1, Spring 2022

different kinds of rules (see Figure 1). Consider, for example, the contrast between computer commands and moral rules. Computer commands, like those that constitute the operating system of the computer that I am typing this essay on, are imperative contents. These rules tend toward being maximally concrete, and range in their prescriptions from the permissive to the restrictive. On the one hand, they are quite simple, yet their ability to guide even modestly complicated behavior depends upon prohibitively lengthy strings of commands—it is not uncommon for a computer operating system to include on the order of 100 million lines of code. On the other hand, moral rules—or, for Dworkin, principles—can be incredibly abstract, determining action in countless situations, contexts, or practices. For example, a general moral prohibition against harming might determine right action in contexts ranging from war to participation in sports to childhood interactions with siblings. Like computer commands, moral rules may be both restrictive and permissive; Immanuel Kant, for example, thought that humans have an absolute or perfect duty to refrain from lying to others, but a permissive or imperfect duty to cultivate whatever natural talents that they may possess. Many laws seem to lie intermediate with respect to these two cases, benefitting neither from the simplicity of individual computer commands, nor the relative sparsity of moral rules. The reality is that legal contents range from the maximally concrete to the very abstract, whether one characterizes them as rules or as something else, such as imperatives or normative propositions. As such, following the law means dealing with a great deal of variously abstract rules, some of which are quite restrictive, and others of which are quite permissive, but many of which bear on one another in understanding the law in toto.

The Semantic Problem

Another problem posed by legal rule-following results from the fact that the laws are written in natural languages and natural languages are notoriously irregular and imprecise. For one thing, rules often admit of an objectionable degree of vagueness, which generally, a rule-follower needs to resolve. This problem seems to become more pronounced as rules become more general because such rules tend to be more dependent upon words with rich semantic content. For example, the words "proportionate," "necessary," "reasonable," and "suffering" each play an important

role in law. In the discussion section of a research report conducted by Igor Grossman, et al. the authors agree with findings from a 1993 study by Eldar Shafir et al. that colloquial use of the term reasonable "concerns a pragmatic focus on social norms and context specificity in the process of judgment."17 Grossman, et al. note that this is distinct from colloquial judgments about rationality, which appear to be primarily focused on individual preferences and attributes. To the extent that social norms vary across communities, this suggests a real difficulty for rule-following in that the meaning of a rule may similarly differ across communities. Granted, Grossman, et al. focus specifically on the folk use of the word "reasonable" because the term plays an especially significant role in the law, but it would be surprising if social norms did not play a significant role in common understanding of other legally significant terms (for instance, "proportionate," "necessary," and "suffering"). Even limited to the word "reasonable" though, the problem is significant.

Consider, for instance, Article 57 (4) to Additional Protocol I to the Geneva Conventions states:

In the conduct of military operations at sea or in the air, each Party to the conflict shall, in conformity with its rights and duties under the rules of international law applicable in armed conflict, take all reasonable precautions to avoid losses of civilian lives and damage to civilian objects.18

The use of a reasonableness standard in this law is not just problematic on account of some vexing terminological ambiguity; it is objectionable because the meaningfulness of the law depends upon the meaning of the word "reasonable," which is difficult to fix. A high standard of reasonableness directs a highly restrictive rule, while a low standard directs the exact opposite. The entirety of prescriptive work done by the law depends upon a single word and the meaning of that word is incredibly difficult to fix, even