UNCERTAINTY IN PRIVATE LAW: RHETORICAL DEVICE OR SUBSTANTIVE LEGAL ARGUMENT?

• Date: 01 August 2021
• Author: Bigwood, Rick

CONTENTS I Introduction II Certainty in Law in General A Examples of Uncertainty Arguments B Flexibility in the Law as a Desirable Quality III General Concepts in Private Law IV Legal Concepts That Are Vulnerable to Attack on Uncertainty Grounds A Unconscionability B 'Reasonableness' in the Tort of Negligence C 'Serious' Breach of an 'Intermediate' Contractual Term D Vicarious Liability: 'In the Course of Employment' and the 'Close Connection' Test E Revisiting Duress and 'Unlawfulness' of the Pressure Applied V Substance versus Rhetoric: Putting Uncertainty Arguments into Perspective A Uncertainty as Rhetoric to Preserve the Status Quo B The Critical Criterion for Scrutinising a Concept: Are There Sound Normative Foundations for It? C The Potential Uncertainty of Bright-Line Rules D A Variation on Uncertainty Arguments: Arguments against Weighing Up 'Incommensurables' VI Conclusion I INTRODUCTION

This article addresses arguments about 'certainty versus uncertainty' in private law. More specifically, it examines the normative weight of 'certainty' as a legitimate end in private law theory and adjudication. A perennial feature of commentary and curial judgments in private law, as in the law more generally, is an insistence, by many, on certainty and predictability as predominant juristic goals. Indeed, that a legal concept is capable of being described as 'nebulous' in its nature, 'vague' in its meaning(s), or 'uncertain' in its application(s) is often advanced as a weighty, if not decisive, reason for rejecting it. This is particularly the case where the concept is contested, emergent or operative at the fringes of the pocket of law under consideration, such as in cases involving 'lawful-act' duress. (1) Courts and jurists often assign additional force to such arguments when considering doctrines, or administering doctrinal criteria, that may impact adversely upon the enforceability of transactions that are 'commercial' in nature. (2)

Such claims of uncertainty, however, tend to neglect or ignore a simple proposition: namely, that the same criticism could equally be levelled against many established jural concepts, and yet it is not. This article aims to demonstrate that criticism of jural concepts (principles, application criteria, etc) as too uncertain or vague is often selectively made: (3) that is, as nothing more than a rhetorical manoeuvre to attack a concept that a court or particular commentator does not favour. (4) Despite their similarly open-textured nature, numerous other concepts--'reasonableness', 'seriousness' (of breach), 'in the course of employment', and the like--are, for some unarticulated reason, spared from the same level of scrutiny or scrupulous demand for legal certainty. Indeed, '[i]f vagueness were a sufficient reason for repudiating legal concepts and criteria, large portions of current law would be eviscerated'. (5) In many instances, the law, given its complex nature and society's expectations of what it is meant to deliver, cannot avoid resort to concepts whose meanings are unfixed and whose applications leave considerable scope for expert judgement--so-called 'leeway of choice'. This is especially so when adjudicating the propriety of party conduct, in the often complex matrix of circumstances within which the conduct is alleged to have occurred, and, further, in fashioning an appropriate legal response when such conduct is found wanting.

In short, arguments of 'too much uncertainty' resulting from the recognition or application of a legal concept or principle are typically enlisted for the purpose of: (1) rejecting the concept or principle as operative in the legal context under consideration; (2) expressing a preference for some alternative concepts) or principle(s); or (3) at a minimum, exercising appropriate caution about the reception or maintenance of the concept or principle at hand. Such arguments tend not to be 'substantive' in the sense that they are neither based on methodologically robust datasets of actual negative impacts occasioned by the alleged or feared uncertainty, nor supported by compelling normative reasons --consequentialist or otherwise--as to why certainty should trump competing principles and purposes enlivened in the particular context. (6) Such arguments could, however, be substantive if, say, they were linked to the search for clarification of the core normative values or conceptual boundaries of the challenged general concept or principle. Yet, in our experience, courts continue to develop and apply a number of open-textured rules, standards and criteria that remain insufficiently tethered to a convincing rationale for their existence or form. It is that failure--to provide cogent and coherent normative foundations for particular concepts--that might well validate fears based on uncertainty, rather than the flexibility of relevant rules, standards and criteria per se. We return to this issue in Part V(A) below.

In our view, courts and commentators who rely on uncertainty arguments of the type envisaged by this article must reflect more critically (than they currently do) on what 'uncertainty' means, what 'too much' uncertainty is, and whether certainty is a feasible--let alone desirable--juristic goal in the relevant context or connection, all things considered. Further, they ought to assess whether the same criticisms might not equally be levelled against the vast corpus of law, in so far as it is expected to justly regulate complex interactions between autonomous actors, in highly variable circumstances, within deeply intricate relationships, in the face of almost inevitable factual uncertainty. In short, in order to have genuinely persuasive force, arguments from uncertainty must credibly rise above the level of assertion or speculative fear on the part of those who advance them, and be grounded instead in either experience or fully articulated reason.

None of this, of course, is to suggest that certainty is not an important legal objective. On the contrary, (un)certainty arguments are often motivated by legitimate concerns about the preservation of the rule of law and, more specifically, ensuring that the exercise of judicial power remains predictable and constrained by legal method, as opposed to being arbitrary. (7) Still, provided they are properly understood, we doubt that concepts that unavoidably generate a level of uncertainty in their application are, for that reason alone, incompatible with the rule of law. (8) As this article seeks to demonstrate, such concepts are an important part of the legal toolkit, especially when one starts from the premise, as we do, that the primary criterion for judging the efficacy of legal rules, principles, standards and directives is that they are both rational and capable of delivering 'real justice' for those subject to them.

This article proceeds as follows. In Part II, we consider the use of uncertainty arguments in law in general and provide specific examples of uncertainty objections that have been made in the private law context. In Part III, we briefly consider the widespread use of 'general concepts' in private law adjudication before, in Part IV, supporting our observations with specific examples of rules, principles and formulations that are vulnerable to attack on uncertainty grounds, but which are nevertheless entrenched in private law. We then turn to consider a concept that has struggled to achieve the same level of acceptance among courts and (particularly) modern commentators--namely, lawful-act duress. In Part V, we offer some observations about the persuasive force of arguments that are directed at the legitimacy and functionality of open-textured legal concepts, before briefly concluding in Part VI.

II CERTAINTY IN LAW IN GENERAL

A Examples of Uncertainty Arguments

Demands for 'certainty' in the law tend to reflect at least two different, albeit interwoven, aims: (1) certainty as to the correct formulation of the relevant legal rules, principles or criteria dehors a particular case--hereinafter referred to as 'expositional certainty'; and (2) certainty as to the outcomes of the application of those rules, principles or criteria in a particular case--hereinafter referred to as 'predictive certainty'. Legal certainty, particularly of the predictive variety, may also be diminished not because the relevant legal rule, principle or criterion is inherently uncertain, but rather in virtue of challenges presented in ascertaining the factual basis of the particular dispute needing to be resolved. (9) That, however, is a matter not pursued here. All else being equal, any factual uncertainty will naturally be compounded by concurrent legal uncertainty.

Expositional uncertainty is not uncommon, although conflicting or confusing decisions as to the substantive law may, over time, become resolved. A recent example is the resolution by the United Kingdom Supreme Court in Patel v Mirza ('Patel') of ongoing uncertainty--following dissatisfaction with the decision of a divided House of Lords in Tinsley v Milligan (10) and conflicting statements in the Supreme Court (11)--as to the applicable test for determining whether a claim is unenforceable as a result of illegality. (12) However, uncertainty in stating the law is unlikely the chief concern of those critical or intolerant of legal uncertainty. Rather, it is the uncertain application, actual or feared, of indeterminate concepts, principles and rules (etc) that is the target of much of the scrutiny and commentary in the field, (13) and which is the focus of this article. A principle or directive that 'the court may, in a defined circumstance, [pi], choose among outcomes A to Z' is certain in the expositional sense, but potentially unpredictable in the outcomes that will be produced from case to case.

Calls for greater legal certainty are ongoing across the various departments of private law. Multiple examples exist, but recent ones...