A. Clarifying Knowability and Ignorance of Language

Let me begin by clarifying Knowability and Ignorance of Language a bit, to avoid certain misunderstandings. First, it is important to distinguish Knowability from the significantly stronger, internalist thesis that in order for something to count as a reason for action, it has to be knowable that the favoring relation holds between the relevant fact and some course of action. Some externalists, although by no means all,Footnote ²³ would presumably reject this stronger accessibility thesis, even in its weakest form,Footnote ²⁴ but I take it that there is very little—if any—reason for even the staunchest externalist to resist the weaker thesis on which the puzzle relies, i.e., that the relevant fact itself has to be knowable.

Second, it helps to get clear about the modality involved in Knowability. On Raz's account, Knowability is a rather strong condition: for something to count as a reason, someone at the time would have found out about it had they put in their best efforts.Footnote ²⁵ Most naturally, perhaps, this is read to apply to the agent herself, for which the relevant consideration is or is not a reason—namely that had she put in her best effort, she would have come to know the relevant fact.

Now, even if we go along with the idea that there are epistemic accessibility constraints on what it takes for something to count as a reason for action we might worry that Raz's constraint is too strong.Footnote ²⁶ For the purposes of our discussion here, however, the strength of the constraint doesn't really matter, since my argument—if it goes through—will go through even on extremely weak readings of Knowability. The tension with which I'm concerned still arises, for example, given the weaker thesis that something counts as a reason (for a particular agent) only if it can in principle be known by an agent with normal human epistemic capacities under idealized conditions.

Although there are even weaker versions of Knowability, this naturalistically specified level of constraint ensures that the tension arises even if we adopt an orthodox epistemicist account of vagueness (on which an omniscient being, for example, would know all the true borderline propositions). Of course, if we instead adopt a semantic or ontological account (or certain unorthodox epistemicist accounts), then an even weaker constraint suffices, since—on such accounts—borderline propositions cannot even be known by cognizers with perfect epistemic capacities. The bottom line is that as long as there is any epistemic accessibility constraint on what it takes to be a reason, this will cause serious misalignment in the set of theses relevant to judicial discretion.

I take these weak versions of Knowability to be overwhelmingly plausible, and consistent with both internalism and externalism about reasons. Whatever reasons are, there is surely some link between the relevant facts and our access to them, however weak and counterfactual. I'm not sure I would even know how to conceive of a reason that an idealized agent, under idealized conditions, cannot even in principle be responsive to—at least under ideal conditions, the favoring relation between some fact r and some action A seems to go hand in hand with the ability of an ideal agent to do A on the basis of r. Hence, we ought to embrace at least some version of Knowability, which is all we need to get the puzzle going.

Third, it is important to note in relation to Ignorance of Language that when we are considering whether a proposition is knowable (relative to a cognizer), we hold fixed everything that is relevant to its truth-value in the world of evaluation. As Wright (2003) points out, the modality involved in knowability claims—at least as they feature in the debate about the nature of vagueness—is “constrained by the distribution of truth values in the actual world.”Footnote ²⁷ Among other things, this allows us to fend off the immediate worry that some borderline propositions are in fact knowable. Consider, for example, Joe, who is (actually) borderline tall. Now, he might of course have been determinately tall, in which case the proposition that Joe is tall is—in some sense—knowable, despite being indeterminate in the actual world. This might be due to John's being taller in some possible world, or it might be due to a different standard of evaluation for “is tall.” It is far beyond the scope of this paper to discuss further ways in which borderline propositions might be knowable in this unconstrained sense. This much is clear, however: it is important to keep the constrained modality in mind throughout the paper, or else my argument will be unduly taken to fail for (at a minimum) any contingent singular borderline proposition, i.e., for any case in which a contingent property is predicated of a particular object (such as when “dwelling” is predicated of P*).

B. “No Reason Either Way”?

It might be suggested that—contrary to what has been assumed so far—cases of vagueness in the law should be analyzed not as cases in which it is indeterminate whether the law provides a reason to do as directed (call this the standard analysis), but as cases in which the law fails to provide reason either way. If that is correct, then the fact that Knowability entails the absence of reasons is not inconsistent with Discretion. We just have to be careful to keep in mind that this absence “goes both ways,” as it were.Footnote ²⁸

It may seem reasonable, for example, to say that—due to the borderline status of P*—council tax regulations neither require B to pay nor permit her not to pay. And that, as a result, the law neither requires officials to treat B as having had reason to act as prescribed nor requires the contrary. Perhaps an “absence of reason either way” analysis dissolves the problem, by allowing us to block the move from Vague Law to Vague Legal Reasons?

Despite the prima facie appeal of the suggested analysis, the answer—I think—is no. Consider, first, a reading of it on which the relevant notion of permission is that of weak permission, characterized as nothing more than the absence of prohibition. On such a reading, we can simply reproduce the puzzle, since it will be trivially true that whatever is not prohibited is permitted (call this the permissive closure principle).Footnote ²⁹ Given permissive closure, the proposed analysis entails a contradiction, in which case borderline cases are analytically impossible. The permissive closure principle thus functions much like the knowability constraint does in the puzzle as originally presented.

If, on the other hand, we interpret permission strongly, then the proposed analysis says—roughly—that, in the relevant legal system, there is neither a norm requiring ϕ-ing nor a norm permitting not ϕ-ing. On this reading, the permissive closure principle is far from trivial, but also highly controversial. On some theories of law, the principle will be necessarily true, in which case there are no gaps of this sort;Footnote ³⁰ weak and strong permission are equivalent and the puzzle can therefore—as before—be reproduced. On other theories of law, it is contingent whether the principle is true, relative to particular systems of law.Footnote ³¹ Thus, if the principle is false relative to a given legal system, then that system will contain gaps of the proposed sort—so at least for those systems, the puzzle is not reproduced. However, in the remaining systems, the fact that the principle is true entails that there is no discretion in borderline cases, which is problematic, since—intuitively—borderline cases (and thus judicial discretion) remain even when a system permits whatever is not prohibited.Footnote ³²

This last point leads me to a more fundamental worry about the suggested analysis, namely that it makes no distinction between borderline cases and cases about which the law is genuinely silent. This is a distinction that we have reason to preserve, and one that Raz—in particular—has been careful to make.Footnote ³³ Council tax regulations, for example, neither require me to eat healthily nor permit me not to eat healthily. And they neither require me to wash my car nor permit me not to wash my car. But to say that officials have any form of discretion with respect to these circumstances would be extremely odd, absurd even; there seems to be a clear jurisdictional difference between borderline cases and cases about which the law is silent, which is unaccounted for by the proposed analysis. Granted, there is (at least on certain views of vagueness) a sense in which both types of cases are undecided and the analysis perhaps manages to capture this, but, on the assumption that judicial discretion is a function of the reasons that applied to the subject at the time of acting, collapsing the distinction between borderline cases and silences severely overgenerates such discretion.

I do not mean to indicate that it is impossible to meet this worry, but it would require an account of judicial jurisdiction robust enough to adequately distinguish between those cases about which the law is completely silent and those about which it is silent but still in some relevant sense “purports” to regulate, despite the fact that—on the suggested analysis—both types of cases are supposed to have the same basic normative structure (characterized by an absence of reasons). This is a tall order, I think—in part because I doubt that there are any cases of the latter sort—but if such an account could be had, this might allow the proponent of the “absence of reason either way” analysis to say that judicial discretion is a function not of the absence of reasons tout court but of the absence of reasons within the scope of the relevant court's jurisdiction, and that cases of vagueness are in fundamental respects like the ones that the law purports to regulate.

Although I am skeptical that the relevant distinction can be adequately made, one reason for thinking that it can might come from considering laws that incorporate reference to evaluative notions. Some might want to claim, for example, that due to the unconscionability doctrine in contract law, parties to a contract are—prior to adjudication—neither conclusively required to act in accordance with the relevant agreement nor conclusively permitted to act contrary to it. And that this is clearly different from how the law treats people's diets and car maintenance: the law in some relevant sense purports to regulate the former but not the latter, or so the thought goes. Of course, to raise the mere possibility of such cases is not to provide an account of judicial jurisdiction (i.e., of what it consists in and what follows from that), but thinking along these lines perhaps suffices to show that there may be principled ways to address the overgeneration worry.

This may be so. Still, it remains the case that, in addition to the need for a suitable and robust enough account of judicial jurisdiction, we would both have to adopt a theory of law on which the strong permissive closure principle is contingent and concede that the proposed “solution” to the puzzle would apply only to those systems relative to which the principle is false. And we would also be stuck with the counterintuitive result that in systems in which there is no discretion in intrajurisdictional cases about which the law is silent (i.e., systems relative to which the permissive closure principle is true), there is—by the same token—no discretion in borderline cases; whereas, intuitively, we could have the latter without the former, and vice versa. The standard analysis, by contrast, does not suffer from any of these problems. All in all, then, vagueness in the law seems better analyzed in terms of it being indeterminate whether the relevant subject has a reason to act as the relevant provision prescribes.Footnote ³⁴

C. Retroactivity to the Rescue?

Most legal systems allow law to be applied retroactively in certain cases, either by legislation or by judicial decision-making. In the United States, for example, retroactive tax legislation is not unheard of. And in the United Kingdom, it seems fair to say that judges have significant leeway to introduce changes into the law, based on extralegal considerations. When a common law rule produces an unjust outcome, for example, the court may decide that certain features of the relevant case allow it to be distinguished from other cases to which the rule applies; in this way, conduct that was determinately legal at the time is sometimes made illegal retroactively. This complicates the picture I have presented, since every actual legal system allows for at least some exceptions to the rule that cases in which the defendant determinately did not violate the legal norm in question ought to be decided in her favor. This will not change the fact that, given Ignorance of Language, Vague Legal Reasons and Knowability are inconsistent, but it certainly makes it less clear that the same goes for Knowability and Discretion.

Intuitively, defendants have a weighty complaint about being found against if they determinately did not violate the legal norm in question; call this the No violation! complaint. However, if the adjudication of borderline cases involves (legally sanctioned) strong retroactivity, then such a complaint will—as a general matter—not be available in such cases. On the assumption that a No violation! complaint is indeed unavailable in borderline cases—supported both by intuition and by actual legal practice—positing strong retroactivity thus seems provide a reasonable explanation for this “datum,” or in any case preserves consistency with it. Perhaps the issue I am pointing out is less consequential than I make it out to be?

The answer, I think, is no. Although the resolution of borderline cases does involve retroactivity, there is—at least intuitively—a clear difference between a case in which a person is, say, convicted of an offense that was determinately not part of the law at the time of action (strong retroactivity) and a case in which a person is convicted for doing something that is borderline illegal (weak retroactivity). All else equal, the former seems worse than the latter, which is—I submit—explained in part by a difference in the reasons involved. In the former case, the defendant did not—at the time of her action—act contrary to the reasons provided by the norm on the basis of which she is being convicted, while in the latter case it is indeterminate whether she has done so. Thus, intuitively, Discretion employs a weak notion of retroactivity/discretion, rather than a strong one. So although we could understand Discretion in terms of strong retroactivity and doing so would suffice to explain why the No violation! complaint is not available to defendants in cases of vagueness, weak retroactivity seems to me to provide a more straightforward explanation of the same phenomenon.

It is worth pointing out, though, that there are also problems downstream from a strong analysis of Discretion. Actual legal systems neither confer unlimited lawmaking power to judges nor contain norms that specifically permit strongly retroactive judicial decisions in borderline cases.Footnote ³⁵ It might of course be suggested that, in each actual legal system, borderline cases somehow form a subset of the set of cases in which such decisions are permitted; perhaps, some more general—but still limited—norm guarantees strong judicial discretion in borderline cases. It is difficult to see, however, how this holds true of any actual legal system, let alone of all (which would be required in order to block the puzzle this way). Consider, for example, the US legal system. Under what general norm permitting judges to apply law retroactively could borderline cases—as a unified class—conceivably fall?

D. Expanding the Domain of Legal Reasons (Conservatively)?

It might be suggested that the way I have construed the domain of legal reasons is too limited. Just as we can—at least on some accounts—sometimes convert partial beliefs based on evidential probabilities into outright beliefs about chances/epistemic probabilities,Footnote ³⁶ or approximate truth into full truth,Footnote ³⁷ we can also sometimes convert borderline cases into knowable propositions: if P* is a borderline case of the predicate “dwelling,” for example, then presumably it is true and, perhaps even knowable, that this is so.Footnote ³⁸ Maybe this fact is appropriately regarded as a legal reason, and one that B acts contrary to in some significant sense if she does not pay council tax?

Some authors put (something like) this idea in terms of subjects being “put on notice”—that if they do not do as directed in borderline circumstances, then they may be subject to official action, such as prosecution and punishment.Footnote ³⁹ Usually, albeit not universally, this provides subjects with a reason to err on the side of caution in such circumstances, a reason that seems grounded in the law in a way that is not totally dissimilar to the case of “normal” legal reasons—especially if they conform better to the reasons that apply to them by so erring. Maybe the solution is to say that acting contrary to a “notice-based” reason in a borderline case is tantamount to it being indeterminate whether one acts contrary to a legal reason provided by the relevant legal norm, in which case it is indeterminate whether one violates it?

I am not prepared to rule this option out entirely, but I think we have good reason to think that it doesn't work. I do think that—at least in some cases—the fact that it is indeterminate whether p is a reason for A to ϕ. I want to resist, however, the idea that it is a legal reason.

Now, for practical reasoning in general, I think it is true that the fact that it is indeterminate whether p is one of the things that can “kick in” in circumstances in which the case for a course of action depends on p. Say, for example, that there is a drizzle outside, such that it is indeterminate whether it is raining. If it were clearly raining, that fact would be a reason for me to bring an umbrella, should I venture outside. But since it is indeterminate whether it is raining, I cannot—assuming a standard account of vagueness—know that it is raining (or, for that matter, know that it is not raining). Hence, if we assume Knowability, that it is raining is not a reason for me to bring an umbrella. Usually, however, this is of limited practical significance. The reason is that other considerations tend to kick in and determine what we ought to do. The same facts about the world that make it the case that it is indeterminate whether it is raining can presumably constitute a reason for me to bring an umbrella, for example because they make it sufficiently probable that it will rain. The general thought here is that, in determining what to do, we can usually replace things that we don't or can't know with things that we do know—and this includes cases of vagueness.

I say “usually” because there do seem to be cases of practical reasoning in which it is much less clear that any other considerations kick in in this way. Consider, for example, the difference between the father who promises to take his family to the park on Sunday if it isn't raining and the person who randomly promises to give a stranger ten bucks if the next guy she sees is bald. In the former case, if on Sunday it is indeterminate whether it is raining, presumably the father ought still to take his family to the park. Granted, that it is not raining may not be a reason for him to do so, but other reasons kick in, making the overall balance of reasons count in favor of taking them to the park (although it could go either way, depending on the circumstances). In the random promise case, if the next guy that the promisor sees is borderline bald, then that the guy is bald is not a reason for her to give a stranger ten bucks (assuming Knowability). In this case, however, it is far from clear that any other reasons kick in. For one thing, no stranger reasonably expects to get ten bucks.

Suppose, however, that there were in fact a reason for the promisor to err on the side of caution and give the stranger the money, perhaps due to threat of violence, or something of that sort. In this case, it seems to me that even if we counted the fact that it is indeterminate whether the man is bald as being among the promisor's reasons, it would be very odd to call it a promissory reason. We may have all sorts of reasons “downstream” from having made a promise, but only some of them are properly labeled promissory. The same, I think, applies to the case of legal reasons. People may have reasons to err on the side of caution when it comes to borderline cases of illegal conduct, or even reasons to run the risk, but I hesitate to call these legal reasons. For one thing, to keep the comparison to promissory reasons, it would seem odd to say that if the promisor did not give the stranger the money, she would be breaking her promise. And it doesn't seem any more palatable to say that, in virtue of whatever is the relevant downstream reason, it is indeterminate whether she would be breaking it. Similarly, it seems very strange to say that if a subject acts contrary to a notice-based reason associated with the enactment of a legal norm, it is thereby indeterminate whether she violates that norm.

It is worth adding that even if we were to expand the domain of legal reasons in some relevant way, the inconsistency between Vague Legal Reasons and Knowability (given Ignorance of Language) would still remain. And, further, if what I said in the paragraph above is correct, we would also be stuck with the No violation! complaint, mentioned in the previous subsection, which would be problematic, since neither intuition nor legal practice indicates that such a weighty complaint is available in cases of vagueness. All in all, then, this suggestion does not seem to provide a robust way out.

E. Whose Reasons?

Another suggestion might be to apply something like the previous response to officials, rather than subjects. Perhaps we can “disconnect” Discretion from the reasons that apply to subjects and focus instead on the reasons that apply to officials in borderline cases, one of which is that it is indeterminate whether A's case is one in which the operative predicate applies? The worry here is that I have been focusing on the wrong set of agents.Footnote ⁴⁰

The best support for a move like this presumably comes from Hart's collective acceptance theory of norms. On such an approach, it is at least conceptually possible that the powers of discretion conferred on judges via the rule(s) of recognition are constitutively independent of anything to do with the subject's reasons. Although contrary to what I think is actually the case, it could be claimed that the accepted norm in relation to adjudication is just that in borderline cases judges have certain normative powers, and that borderline cases are defined simply by reference to the operative predicate, in which case judicial discretion is independent of the normative situation of the subject. Discretion, instead, would be a function of Vague Law, rather than of Vague Legal Reasons (as the puzzle assumes).

While I think it is not so counterintuitive to take propositions about indeterminacy (as opposed to indeterminate propositions) to be among the legal reasons that officials have in borderline cases, it is quite problematic to disconnect Discretion in this way. In addition to the factual doubts already mentioned, it would require giving up the most straightforward and robust basis for the notion of judicial discretion in borderline cases, i.e., that it comes about as a consequence of it being indeterminate whether a norm has been violated. Severing this link thus seems both factually problematic and theoretically costly.

Further, on a noneliminative collective acceptance theory of norms like Hart's,Footnote ⁴¹ the relevant group's acceptance can be partly—but crucially—characterized in terms of a “normative perspective,” which can help relieve an equally significant part of the tension without requiring us to revise our understanding of the basis of judicial discretion in the way suggested. The bulk of my argument on this point is set out in Section II.H below, but to anticipate the basis of it, consider how the acceptance in question grounds a “point of view.” With respect to judicial discretion, the collective acceptance of the relevant officials for example makes it the case that “from the point of view of the law,” in cases where it is indeterminate whether the subject has violated the norm in question, judges are—assuming no other norms conclusively apply—not bound to decide the case one way rather than the other, but may reason either way. A similar analysis applies to first-order norms that apply to subjects: if the law prohibits, say, ϕ-ing, then, for any subject S, S has—from the point of view of the law—a reason not to ϕ. And the principle that a subject violates a legal norm only if she acts contrary to a legal reason provided by that norm here presumably takes the following form: a subject S violates a legal norm N iff, from the perspective of the law, A acts contrary to a reason provided by N. As I explain in Section II.H, we can—in a significant enough sense—reject Knowability for such perspectival reasons (despite accepting the thesis for “real” reasons), in which case the above suggestion to disconnect judicial discretion from the subject's normative situation becomes entirely unnecessary. Of course, none of the concerns I have raised here by itself constitutes a knockdown argument against this suggestion, but together I think they give us good reason to seek other ways to address the puzzle.

Of course, some might respond by embracing the link between judicial discretion and the notion of violating a norm, but stipulate that for a subject S to violate a legal norm just is for S's actions to fail to satisfy the operative predicate in the relevant circumstances (rather than to have acted contrary to a legal reason provided by the relevant norm, however conceived). This is, in effect, to reject a reasons-based account of legal norms altogether. On such a suggestion, the very foundation of the puzzle is removed, as the move from Vague Law to Vague Legal Reasons is blocked, in which case the inconsistency with Knowability is not generated. The No violation! complaint would of course also go away.

I don't want to claim that this more radical move would not offer a possible way out, but giving up a reasons-based account of legal norms is ultimately too costly, I think. Not only does this strategy lead to an impoverished analysis of judicial discretion—so impoverished that one would have to reject not just the puzzle but the subject matter itself—it would actually no longer make sense to talk about legal norms, since normative notions like obligation, power, permission, and so on, are arguably best analyzed in terms of reasons.Footnote ⁴² Indeed, norms are—I think—(at least partly) constituted by the reasons to which they give rise. This is of course only a problem if we want to be able to talk sincerely about law as a normative system, but then—at least absent a wholesale rejection of normativityFootnote ⁴³—I do not see how we could take law not to be a normative phenomenon. So this “solution” comes at a price that I, for one, am not prepared to pay.Footnote ⁴⁴

F. Does the Argument Equivocate?

So far, I have—in line with most standard theories of vagueness—been taking it for granted that the unknowability involved in Ignorance of Language and Knowability is of the same kind. But what if the former employs a specific vagueness-related notion of ignorance while the latter employs an ordinary factual notion? In that case, the argument equivocates and the problematic inference doesn't go through.

The idea behind this strategy is that we can distinguish between two notions of unknowability—one factual and one vagueness-related—and that these have different implications vis-à-vis the epistemic accessibility constraint on what it takes to be a reason. On this suggestion, the factual unknowability of p entails that p is determinately not a reason, but the same does not go for vagueness-related unknowability; instead, in case p is a borderline proposition, the respective ignorance entails indeterminacy regarding p's being a reason.Footnote ⁴⁵

This is a promising strategy, I think, but it comes with very deep commitments in philosophy of language and metaethics (as well as, arguably, in epistemology and philosophy of mind). The main issue is that it would require a theory of vagueness on which vagueness-related ignorance is analytically distinct from ordinary, factual ignorance, or else we can simply reproduce the problem. Of course, all standard theories of vagueness—even Timothy Williamson's epistemicismFootnote ⁴⁶—take indeterminacy to be a special source of ignorance, but it is far less clear that there is supposed to be any difference in the actual ignorance produced. In both cases, the agent does not know whether p, which makes it difficult to claim equivocation on the notion of ignorance at play. It seems clear, then, that in order to make something like this suggestion work, we will have to appeal to something beyond mere ignorance to properly distinguish the factual cases and the vagueness-related cases.

I think we can make some headway here by reminding ourselves that Knowability is a cognitive constraint generated by Raz's Nexus, as a result of what it takes to respond to something using one's rational powers. Perhaps, when p is indeterminate, the Nexus has different implications for what is cognitively required in order for an agent to rationally respond to p? This is not an entirely unexplored question, but—as Robert Williams notes—there is very little consensus about what the cognitive role of indeterminacy is, i.e., about what attitude(s) one ought to take toward p, when (one knows, or believes, that) p is indeterminate.Footnote ⁴⁷ Still, I think the bare-bones idea provides enough grounds to distinguish between the following two principles (using “X” as a placeholder for the relevant attitude(s)), which is all we need to make the strategy under consideration palatable:

The strategy here, then, is to claim not that the argument equivocates, but—rather—that it mistakenly applies Knowability to cases of vagueness, when in fact it only applies in determinate cases.

This strategy resonates particularly well with theories on which vagueness is to be explained primarily in psychological terms, in part—but crucially—by elucidating what sui generis attitude we ought to take toward borderline cases.Footnote ⁴⁸ Note, though, that the suggestion here is importantly—albeit subtly—different from simply embracing one of the relevant psychological accounts already on offer. Granted, on such accounts, Ignorance of Language is not derivable from the distinctive attitude(s) one ought to take toward p, but these views still generally accept this thesis, either as independently motivated or as a consequence of other features of the particular account,Footnote ⁴⁹ and so we are stuck with the puzzle unless we reject or modify at least one of the other theses involved; hence, the focus here on Knowability and the above suggestion to restrict it to determinate cases. I hope to have shown, however, that paying attention to the attitude(s) one ought to take toward borderline cases can help sever the link between Knowability and Ignorance of Language, by prompting us to take a closer look at Raz's Nexus. But it is by no means an easy way out—in order for it to work, a lot more needs to be said about the cognitive role of indeterminacy.

G. Rejecting Ignorance of Language, or at Least Its Consequences

One of the assumptions of both the puzzle and the previous suggestions—and of much of the debate about vagueness, both in philosophy and in law—is that there are in fact clear borderline cases. Over the past two decades or so, however, this assumption has been met with increasing resistance and some authors now favor views that seem to better respect the actual difficulty of forming reliable judgments about borderline cases.Footnote ⁵⁰ As it is still a widely held assumption, I go along with it for the sake of argument, but it is worth pointing out what happens once we give it up.

Not everyone will agree, and—as we will see below—some authors prefer to provide other grounds for the same result, but rejecting the assumption that there are any clear borderline cases arguably limits the effect of Ignorance of Language in the following way: if, for the relevant range of cases, it is never clear whether it is indeterminate whether a predicate applies to an object (relative to a context of utterance), then it is indeterminate whether it is unknowable whether the predicate applies to that object (in that context). Ignorance of Language might of course still hold as a penumbral connection, but it would no longer have the problematic consequences that fuel the puzzle.Footnote ⁵¹

Some authors have also proposed grounds for rejecting not only the consequences of Ignorance of Language but also the thesis itself, although these accounts remain nonstandard. For example, David Barnett joins Cian Dorr in arguing that it might be indeterminate whether a fully informed person knows whether p, in case p is indeterminate.Footnote ⁵² There are some differences to their arguments, but basically they agree that it might be the case that if it is indeterminate whether p and some suitably specified cognizer knows all the relevant facts, then it is indeterminate whether she knows whether p. There will simply be no fact of the matter regarding which epistemic state she is in, given full knowledge of the relevant facts.

To be sure, any suggestion to revise Ignorance of Language will be highly controversial, and the thesis is still representative of any standard account of vagueness, but if the revised version of it turns out to capture the correct understanding of the relationship between vagueness and (un)knowability, then the tension between Knowability and Discretion is indeed relieved. Consequently, this option would allow us to retain all of the puzzle's legal and metaethical theses, but our commitments in philosophy of language would run pretty deep.

Still, it is probably the “simplest” strategy on offer. And—fittingly—such accounts would, I think, entail that it is indeterminate whether borderline propositions can guide action. That is, if it is indeterminate whether p, then it is—on these views—indeterminate whether p is knowable to the agent; consequently, it is indeterminate whether she would be able to respond to p using her rational powers.

H. Rejecting, or at Least Modifying, Knowability for Legal Reasons?

As alluded to in Section II.E, there is another promising way to relieve the tension between Knowability and Discretion: to accept Knowability for “real” reasons but reject it for “pure” legal reasons. Although restricting Knowability and revising Ignorance of Language are in some sense easier options, I think we may learn more about the normativity of law by examining whether, or at least in what way, Knowability applies to legal reasons.

As Scott Shapiro has usefully pointed out—drawing heavily on Raz's influential notion of a detached legal statement—we can distinguish between (at least) two senses of “legal reason.”Footnote ⁵³ On one reading, “legal” functions as an adjective—on the other, as a qualifier. On the adjectival reading, a legal reason to ϕ is a real reason to ϕ, the existence of which depends on the operations of legal institutions (suitably understood). A real reason here is just a fact or consideration that in fact counts in favor of some action (subject to any further existence conditions, such as knowability). On the qualified reading, one has a legal reason to ϕ—roughly—just in case, from the point of view of the law, one has a real reason to ϕ (at least partly in virtue of the law having directed one to ϕ). Given the distinction between these two understandings of legal reasons, it makes sense to ask whether Knowability applies equally to both. I think a very good case can be made that it applies—if it applies—to the former, but not the latter.

Now, on the adjectival reading, legal reasons are real reasons that people have in virtue of the operations of legal institutions. Accordingly, if Knowability applies to real reasons, then it applies to legal reasons (in this sense). On the qualified reading, however, legal reasons purport to be real reasons, and so the way in which Knowability applies—if it applies—is less clear. It seems reasonable to say, though, that if legal reasons in a robust enough sense purport or aim to be real reasons, then the epistemic constraint on what it takes to be a real reason is a standard of evaluation for legal reasons, rather than an existence condition—much like, say, an effort to create something of a kind K will be subject to evaluation at least partly by reference to K's essential features (if K has such features). If this is the sense in which Knowability applies to legal reasons on the qualified reading, then p's being unknowable doesn't outright disqualify p from being a legal reason, although it will be a defective one, lacking—as it does—one of the essential features of real reasons (i.e., being knowable).

On this understanding of Knowability, there is no conflict with Discretion, and the tension is relieved. Nevertheless, there is an uneasy asymmetry here. If what I have said is correct, we can evaluate vague legislation partly by reference to the essential features of real reasons—in the case of Knowability, for example, the extent to which individual cases will measure up will vary depending on what it would take to come to know them given one's best efforts. But if we also assume a standard account of vagueness, then the failure—as we have seen—will be total in borderline cases, which seems to predict that we should have a fairly negative view of judicial discretion, more negative than we in fact seem to have. Why would it make sense for officials to have discretion in borderline cases, if such cases constitute a complete failure, vis-à-vis what the law purports to do (i.e., to provide real reasons for action)?

The answer is far from clear to me. To be sure, there is an inclination within most legal systems to treat cases of vagueness “cautiously”—to decide in favor of the defendant, or at least not to be neutral about the fact that they are borderline cases. The common law rule of lenity in criminal law is a prime example. And, sometimes, this is justified in terms of a failure to guide action (adequate notice, due process, etc.). However, as commentators point out, the rule of lenity is less common in criminal law than one might expect, and when it is present, it is often not applied as frequently as one would think. In addition, it is extremely rare to find similar rules outside criminal law. This suggests a significantly less negative attitude regarding judicial discretion than seems predicted by retaining Knowability for real reasons (and thus as a standard of evaluation for legal reasons, in the qualified sense) along with a standard account of vagueness (on which borderline propositions are unknowable).

This is by no means a clear problem, and it may well be that there are many possible explanations of this apparent asymmetry that concern none of the theses that we have been examining here. There tend to be so many considerations at work in deciding legal cases that it is difficult to make firm judgments about how different considerations are weighted against each other, whether in particular cases or—especially—across entire legal systems. It is worth considering, however, whether the asymmetry goes away if we combine the suggestion here with the suggestion from the previous subsection. Perhaps we should both revise Knowability and adopt an account of vagueness on which it is indeterminate whether borderline propositions are knowable? At the very least, what this does—at least ideally—is to align our evaluative attitude toward judicial discretion with the extent to which the law succeeds in its aspirations to provide subjects with real reasons for action.

Here is how the story would go on such an account. Say that it is indeterminate whether some object o (broadly construed) is a borderline case of a predicate P occurring in a legal provision L and that, consequently, it is indeterminate whether, from the point of view of the law, Po is a real reason for A to ϕ. In case A doesn't ϕ, this entails that it is indeterminate whether A violates the legal norm to which L corresponds. If A's case goes to court, then the relevant officials are—assuming no other legal norms conclusively apply to the case (such as a rule of lenity)—neither bound to decide against A nor to decide in her favor. As a result, they may (in some relevant sense) reason either way.

Furthermore, it will—on this account—be indeterminate how such cases measure up to the knowability standard (against which we can partly, but crucially, evaluate legislative directives). This marks a difference, for example, in how we should weigh the law's action-guiding failure in such cases, which is then weighed against other considerations in determining the outcome of the case. I submit that, holding everything else fixed, if we adopt a standard account of vagueness, we ought to give considerably more weight to action-guiding considerations in such deliberations than if we adopt a nonstandard account (i.e., one on which indeterminacy entails indeterminate knowability), due to their different implications for the (im)possibility of knowledge. The latter, I think, is more in line with our intuitions about proper practical reasoning; as concerns action-guidance, there is, intuitively, something worse about retroactive and secret law than vague law. This suggests that although either strategy—i.e., revising Ignorance of Language or rejecting Knowability for legal reasons—will make the puzzle go away, combining the two might be a particularly attractive option.