The field of evidence is no other than the field of knowledge.
The law has no mandamus on the logical faculty.
In any inference task our evidence is always incomplete, rarely conclusive, and often imprecise or vague; it comes from sources that have any gradation of credibility.
The subject of Evidence deserves a more central place in the discipline of Law.
Evidence is important for all of us. Everyone deals with evidence and inferential reasoning every day of their lives, in every kind of work situation, in specialist areas, in academic and historical enquiries and as ordinary citizens in deciding whether to marry, in choosing package holidays, in shopping, in other everyday decisions and in listening to arguments or debating issues. The English system of administration of justice depends heavily on lay magistrates, jurors, tribunal members, umpires and referees and others to make decisions based on evidence. This assumes a general idea of ‘cognitive competence’ on the part of adult citizens – that is to say, that nearly all adult members of society can make rational judgements about questions of fact using ordinary practical inferential reasoning based on evidence.5
In recent years Evidence as a subject has become very topical. More or less simplistic forms of evidence-based medicine, evidence-based policy and evidence-based decision-making in many spheres of life are salient features of bureaucratisation and the audit society. If one applies the Newspaper Exercise to evidence it will be found to feature on every page and evidentiary concepts such as relevance, cogency, plausibility and rationality are an essential part of the discourse. Dope testing of athletes, the use of new technology in decision-making in sports, authentication of art works, problems of proving genocide, DNA, ‘fake news’ and the credibility of ‘experts’ are familiar themes. In popular culture, detective fiction has expanded its horizons to include forensic science (Patricia Cornwell), Forensic Anthropology (Kathy Reichs), scenes-of-crime officers (especially on television) and various forms of intelligence analysis. After 9/11, the starting point for post-mortems was a judgement that ‘American intelligence agencies did not possess the analytic depth or the right methods accurately to assess [possible threats]’.6
Everyone is concerned with evidence; it is important in most spheres of life, especially decision-making, and it has special significance in contemporary public life. Moreover, Evidence is fascinating as a subject of study. Yet, paradoxically, within the discipline of Law it is widely perceived to be a narrow specialism, arcane, technical, esoteric, artificial and of diminishing importance. This perception fits much of the practice of Evidence scholarship, teaching and discourse. That is because that practice is based on a fundamental fallacy: that the Law of Evidence is co-extensive with the field of Evidence in Legal Contexts. This crude conflation is a clear example of the distorting influence of the doctrinal tradition. Evidence specialists, at least until recently, have focused almost exclusively on the Law of Evidence (mainly the rules of admissibility). Perceptions are further distorted by treating the contested jury trial as the paradigm situation of litigation and appellate courts, which have limited powers in Anglo-American law, as the main arena for the development of Evidence doctrine.
This chapter helps to explain this dire state of affairs through the story of my project on Rethinking Evidence, begun in 1972. Some progress has been made since then, but the project is unfinished as the battle is far from won. In particular I have had limited success in persuading all academic lawyers to ‘take facts seriously’ as part of their general intellectual equipment and different specialisms. It is worth summarising the case for this to change.7
Evidence, Proof and Fact-finding (EPF) is important for all academic lawyers, not just specialists, because:
1. Understanding evidence is an important part of understanding law.
(a) EPF is important for legal theory because it raises a whole range of theoretical issues that are generally marginalised in the agenda of mainstream Jurisprudence.8
(b) EPF should play an important role in the study of many specialised areas of law, e.g. how does one prove causation in conspiracy or genocide or disasters at sea.
2. EPF is important in legal practice, both in litigation and non-litigious business.
3. EPF is a good vehicle for developing some basic transferable intellectual skills. It should, inter alia, be treated as an important part of basic Legal Method.9
4. As the discipline of Law responds to ‘globalisation’, interesting new theoretical and practical issues arise in respect of transnational relations, comparison, generalisation, and hybridisation.10
5. The subject of Evidence is coming into its own as a distinct multidisciplinary field.11
Rethinking Evidence: the story of a project
Jeremy Bentham and the American Realist Jerome Frank originally stimulated my interest in Evidence, a subject that I had hardly encountered in my formal legal education. Moving to Warwick in 1972 committed me to rethinking the subject as my contribution to the Law School’s mission ‘of broadening the study of law from within’. For the next sixteen years or so the study of Evidence in legal contexts was my main project. Thereafter I continued to take an interest and to teach ‘Analysis of evidence’ until I gave up teaching in 2011.12
During the Warwick period I considered that what I was doing was responding to Jerome Frank’s plea to take facts and fact-finding seriously.13 He had plausibly argued that well over 90 per cent of legal practice was taken up with questions of fact,14 but almost all academic attention was focused obsessively on questions of law in superior courts – a disease known as ‘appellate court-itis’.15 The disease persists today. The focus needs to be adjusted. Frank’s thesis was correct, but he never worked out a satisfactory way of implementing it in his teaching or writing. Thus, the standard accounts of the subject of Evidence in Law have continued barely to reflect the actual problems and practices of lawyers and lower courts and tribunals, let alone broader conceptions of the field of Evidence in other legal contexts.
A second stimulus was the realisation that Jeremy Bentham had written more about adjective law (evidence and procedure) than about any other subject, but that he had been largely ignored by modern Evidence scholars.16 A third interest was in some particular examples of alleged miscarriages of justice, including the Sacco-Vanzetti case, the tragedy of Edith Thompson and cases concerning atrocities associated with the IRA. A central question was: how can one analyse such allegations in a systematic way?17
My interest in Evidence started at roughly the same time as the development of ‘the New Evidence Scholarship’ in the United States. In the early years that movement was mainly concerned with issues about probabilities and proof, with quite sharp divisions between Baconians (inductivists) and Pascalians (who believe that all probabilistic reasoning is in principle mathematical) – with further divisions between Bayesians, frequentists and other schools of statistics. I joined in these debates, as I did in relation to later issues about the relationship between narrative and argument in legal fact-finding, but my main concerns were broader.18
The project on Evidence roughly divided into five phases which overlapped in time and subject matter.19 First was the establishment of an ideal type of twentieth-century legal treatment of Evidence as an academic subject in order to make a critical assessment of its strengths and limitations. Second was a reconstruction of the intellectual history of Anglo-American approaches to the study of Evidence as a distinct field, from the publication of the first treatise in 1754 by Chief Baron Gilbert to the 1970s. Third was an analysis of the basic concepts of the Law of Evidence and of what Wigmore called the ‘logic of proof’ and of the relations between them.20 Fourth was the consideration of the philosophical underpinnings of previous attempts to construct a general theory of evidence in legal contexts. Finally came the exploration of the role of evidence in other disciplines, in public life and in general culture and to consider the potential of Evidence as an integrated cross-disciplinary field.
A narrow orthodoxy within the doctrinal tradition
The first step was to construct an ideal type of orthodox Anglo-American approaches to the study of Evidence, to articulate their underlying assumptions, and to assess them critically. For example, the subject of Evidence in Law was treated as co-extensive with the Law of Evidence, mainly the rules governing admissibility; the contested jury trial (a wholly exceptional event)21 was treated as the paradigm case for the application of the exclusionary rules; doctrine constituted the whole subject matter of Evidence; this was developed mainly in appellate courts, whereas most action was in lower courts and pre-trial; in Jurisprudence the concept of ‘legal reasoning’ was limited to argumentation about questions of law (typically in ‘hard cases’) and reasoning about questions of fact was usually ignored or dismissed as mere common sense. This ideal type was narrowly conceived and easy to criticise. The real challenge was to construct a coherent conception of the subject of Evidence in Legal Contexts to replace that orthodoxy.
In 1972, shortly after I had joined Warwick, during a highly charged debate at the SPTL Annual Conference on reform of criminal evidence in England, I heard the leading Evidence scholar, Sir Rupert Cross, say: ‘I am working for the day when my subject is abolished.’ This provided a splendid foil for my work – for how could scholars abolish the subject of Evidence in law? What would one study about evidence if there were no rules? How much of Evidence doctrine consists of rules? What would be the place of the Law of Evidence within a broadened conception of the study of Evidence in Legal Contexts? What should we be studying about evidence or ‘evidence plus’ in addition to the rules? By what criteria might one judge what part of our heritage of evidence doctrine might be worth preserving or extending? And was not Evidence – narrowly conceived, riddled with technicality, relatively neglected as a subject of academic study in England and prone to cyclical, repetitious and deeply unsatisfying political debates – ripe for rethinking?
Early on I developed several main lines of criticism against the orthodox contemporary Anglo-American approach in the secondary literature and courses on Evidence. First, it was too narrow. Because it had focused almost exclusively on the rules of admissibility, it had almost systematically neglected a whole range of other questions, such as questions about the logic and psychology of proof and relations with other disciplines such as Forensic Science, Criminal Process and Statistics. Secondly, it was atheoretical: the leading theorists of Evidence had in recent years been largely ignored, and most discussions of evidentiary issues had proceeded without any articulated and coherent theoretical framework for describing, explaining or evaluating existing rules, practices and institutions. Almost all Evidence scholarship had assumed a rather naïve, common-sense empiricism, without much reference to epistemology or philosophical logic. It also failed to confront a variety of sceptical challenges to orthodox assumptions, ranging from Jerome Frank’s fact-scepticism, through politico-ideological critiques, to various forms of epistemological relativism. It had proceeded in almost complete isolation from developments in relevant branches of Philosophy. Thirdly, insofar as orthodox academic discourse had moved beyond simple exposition, it had tended to be incoherent, for the conceptual framework of evidence doctrine did not provide an adequate framework for establishing links with other kinds of discourse. For instance, it did not easily accommodate questions about reasoning about probabilities in forensic contexts, a topic which had recently been given prominence in America and Australia from the late 1960s. Nor did it stimulate interest in the relationship between reasoning about questions of fact and law and other reasonings in legal contexts (Chapter 10).
Fourthly, bare exposition led to distortions and misperceptions of key evidentiary issues and phenomena. A weak version was that by concentrating on some issues to the neglect of others, a misleading impression is given of the subject as a whole. A stronger version is that such imbalances actually lead to misperceptions and error.22 For example, nearly all of the existing literature on confessions treated retracted confessions as the norm; yet in practice retracted confessions represent only a small minority of all confessions, especially in jurisdictions that accept guilty pleas – rather different from mainstream civil law traditions. Typically, neither the scholarly literature nor public debate was based on a balanced and realistic total picture of the role of confessions in criminal process, such as the significance of confessing as an important stage en route to a guilty plea.23 Evidence scholarship failed to give a systematic account of confessions in criminal process as phenomena. It provided no clear answers to such questions as who confesses to whom about what under what conditions, in what form and with what results? Yet how could one make sensible and informed judgments about the issues of policy relating to confessions and interrogation without at least tentative working answers to such questions?
These criticisms suggested some criteria which a broader approach to the study of evidence would need to satisfy in order to meet these objections, insofar as they are well-founded. In 1978 I summarised my response as follows:
To meet the charge of narrowness, it would be necessary to identify at least the most important questions which ought to be tackled in a systematic and comprehensive approach to the study of evidence. This requires an adequate theoretical and conceptual framework.
To meet the charge of incoherence, the relationships between the different lines of enquiry would need to be charted carefully and explicitly – there are, for example, some puzzling questions about the connections between the logic and the psychology of proof, or again, between the study of evidence and proof on the one hand and of criminal and civil procedure on the other.
To meet the charges of theoretical naivety, important theoretical puzzles and disagreements would need to be identified and considered. It is not good enough to dismiss the sceptics, however exaggerated their views may be, by pretending that they do not exist or that what they say is irrelevant.
And to meet charges of distortion and misperception, it is important to paint as realistic a total picture as possible of the phenomena under consideration, so that particular issues can be set in the perspective of some reasonably balanced and realistic overview of the whole. That is part of what is meant by studying law in context.24
Some intellectual history
As I was historically inclined, the next question was: within the common law tradition has anyone tried to do this before? The answer was that for 200 years after the publication of the first treatise, Chief Baron Gilbert’s The Law of Evidence (1754), there had been numerous attempts to develop a ‘theory of evidence’; some of these were restricted to Evidence doctrine, but others had been quite broadly conceived. Rather than try to reinvent the wheel, I devoted some attention to intellectual history. The main exercise was to examine the assumptions underlying leading Anglo-American treatises on Evidence from 1754 to the 1970s, then to explain and construct a further ideal type of the assumptions underlying ‘The Rationalist Tradition of Evidence Scholarship’ to which the ideas of almost all common law specialist treatments had approximated. The tradition was heavily influenced by Bentham – especially the premise that the direct end of adjudication is rectitude of decision – that is, the correct application of rules to facts that were probably true. In short, the enterprise involves the pursuit of truth by rational means on the basis of inferential reasoning from evidence. Bentham argued that there should be no rules of evidence. This was considered too extreme, but the scope of the Law of Evidence narrowed considerably over time. Nevertheless, in the English and American academic traditions the assumption persisted that rules (or more broadly doctrine) constituted the subject matter of the discipline of Law and the Law of Evidence constituted the subject matter of Evidence in Legal Contexts.
The two outstanding figures in the Anglo-American tradition were Jeremy Bentham and John Henry Wigmore. I wrote a book about them (Theories of Evidence: Bentham and Wigmore (1985))25 and used each as a reference point for developing my own ideas. Bentham inspired the model for the Rationalist Tradition. His proposals for reform were considered to be too radical, but almost every change over the next two centuries has moved in the direction that he indicated, but at a slower pace and in a piecemeal way which he would have condemned. Bentham also provided a foil for considering non-utilitarian and various sceptical perspectives.26 It is relevant here to say something more about Thayer’s conception of the Law of Evidence, Bentham’s anti-nomian thesis and Wigmore’s conception of ‘the principles of proof’.
Thayer and Wigmore both emphasised the limited scope of the Law of Evidence. Their view can be expanded to an ‘argument of exaggerated importance’: what has to be proved (materiality) is prescribed by substantive law, not by evidentiary rules; there are almost no formal rules of quantum or priority or weight or relevance. Some doctrine, such as ‘the best evidence rule’, are little more than ‘evidentiary ghosts’; the hearsay rules are a series of exceptions to exceptions to exceptions and, since the near-disappearance of the civil jury in common law jurisdictions (except the United States), it is nearing ghostdom in civil litigation; previously rigid rules have become discretionary guidelines; the surviving rules are often waived or ignored in practice, and many tribunals are ‘guided but not bound’ by them.27
Nevertheless, most evidence scholars, including myself, believe that some exclusionary rules, standards of proof and presumptions are worth fighting for. On the other hand, Bentham went further in attacking all peremptory rules of evidence, arguing that any binding rule of evidence was bound to be over-inclusive or under-inclusive because of the vast variety of combinations of circumstances involved in ordinary fact-finding. This ‘anti-nomian thesis’, although overstated, raises important issues in the theory of norms about rule-governed activities (Chapters 11 and 20).
Bentham’s anti-nomian thesis sounds radical to common lawyers, but in nearly all other spheres of practical life we operate under a system of ‘free proof’ – that is, an absence of formal rules in regard to weight, credibility or quantum as well as admissibility.28 Bentham’s reason is instructive:
To find infallible rules for evidence, rules which insure a just decision is, from the nature of things, absolutely impossible; but the human mind is too apt to establish rules which only increase the probabilities of a bad decision. All the service that an impartial investigator of the truth can perform in this respect is, to put the legislators and judges on their guard against such hasty rules.29
In an age of bureaucratisation, mechanisation and audit, this warning should still have resonance. The pressures to simplify, standardise and codify are greater than ever and some of the main instruments for this are formal rules, other formalisations and algorithms. For example, more extreme versions of evidence-based medicine have tended to move in the direction of rules and protocols of priority and weight (e.g. repeated clinical trials trump single laboratory studies which trump qualitative studies which trump patients’ ‘idiosyncratic opinions’).30 This approach resembles that of Chief Baron Gilbert (1754) (official documents under seal trump other official documents which trump unofficial documents which trump oral testimony). Bentham destroyed Gilbert’s theory in the early nineteenth century.31
Interestingly, the two great expositors of the Law of Evidence confirmed this aspect of Bentham’s thesis, arguing that key questions of relevance and weight could not and should not purportedly be governed by formal rules. As Thayer put it, ‘the law has no mandamus on the logical faculty’.32 Wigmore went so far as to say that a lawyer (invoking rules of weight) is committing ‘moral treason’.33
However, Thayer and Wigmore acknowledged and supported the survival of some rules of evidence. Thayer’s answer to the question ‘what is the Law of Evidence?’ was that the surviving rules are disparate exceptions to a principle of free proof (meaning the absence of formal rules). Wigmore followed this and acknowledged that the remaining rules were of diminishing importance.
Thayer’s thesis raises the question: what is the nature, meaning, extent and justification of freedom of proof? His answer was in terms of ordinary inferential reasoning used in the practical decisions of everyday life. That is important, first, because it is accessible to ordinary adult citizens, who are thus competent to participate in adjudicative decisions based on evidence; and, secondly, because this is the best kind of reason available in most circumstances. In short, ordinary common-sense, practical reasoning is for the most part the best tool we have, despite its obvious frailties. That raises a host of theoretical issues.34
Thayer’s conception of the Law of Evidence still underpins most of the Law of Evidence in the common law tradition. It is the basis of the American Federal Rules of Evidence and several other such codes. Sadly, most expositors and teachers focused on the exceptions – namely, the formal rules – and did not place enough emphasis on the idea that the key to understanding evidence in law is inferential reasoning or what Wigmore called ‘the logic of proof’.
Wigmore built on and developed Thayer’s ideas. He divided the subject of Evidence into two parts, The Principles of Proof and the Trial Rules, and argued that the former are anterior to and more important than the latter and have been marginalised in legal thought and that the neglect of the former has distorted perceptions of the latter. Wigmore made his name with his famous A Treatise on the System of Evidence in Trials at Common Law (1904), which is ostensibly about the rules and which dominated and indeed overshadowed American Evidence scholarship and practice for about fifty years. This still survives as The New Wigmore, but with some healthy competition.35
Unfortunately, Wigmore’s attempt to develop The Principles of Proof was a flop. Presented in an idiosyncratic fashion, it was not taken seriously by either scholars or practitioners. First published in 1913 as The Principles of Judicial Proof, as Given by Logic, Psychology and General Experience, it seems that the publishers only agreed to publish two further editions to humour their star author and they insisted on renaming the third edition (1937) The Science of Judicial Proof, probably in order to suggest that it was a new book.36
The Law of Evidence
Thayer still provides the key to understanding the Law of Evidence in the United States and most common law countries. While arguing that lawyers tend to exaggerate the importance of exclusionary rules of evidence, I concluded that artificial rules of evidence can and do play an important, if narrow, role in reasoning about and deciding issues of fact in adjudication, litigation and more generally.37 Ironically, having set out on a seemingly radical programme, I found myself reviving and defending some key aspects of the Anglo-American tradition that had been forgotten: Bentham’s view of the ends of adjudication, Thayer’s vision of the Law of Evidence as a series of disparate exceptions to a principle of free proof, Wigmore’s chart method and several attempts mainly by American teachers to develop courses on fact-finding and the logic of proof. All of the latter went beyond conceiving of the subject of Evidence in Law solely or mainly in terms of rules. All died in infancy.38
The details of the surviving rules of evidence still remain the main focus of most courses and professional examinations on ‘Evidence’ in the United States and England and of most specialists in the field. I did not follow Bentham in arguing for the total abolition of formal rules. My position is that some of the exclusionary rules, principles and standards are very important, but they are only a small part of the subject and they need to be studied in the context of a broader conception of the field as a whole. In the early days of the project I taught selected topics in the Law of Evidence,39 but later I left much of this to more interested colleagues. Terry Anderson integrated a shortened version of Analysis of Evidence into his course on The Law of Evidence with some success.40 We used examples from doctrine in teaching Modified Wigmorean Analysis (see below), especially to illustrate the relationship between the logical aspects and the rules. In print I made specific criticisms of standard treatments of identification evidence, confessions and improperly obtained evidence, but a more comprehensive and detailed critique of one of the standard expository works might have been more convincing to traditional specialist colleagues. However, my main concern was to try to persuade all academic lawyers to ‘take facts seriously’ and to treat Evidence and Proof as central to the discipline of Law as rules, reasoning and legal methods – in other words, as transcending the main fields of substantive law. This advocacy seems to have been largely unsuccessful, probably because most academic lawyers perceive Evidence to be a highly technical, rather esoteric subject which is no concern of theirs, while many specialists felt that they were targets of my critique.41 That case needs to be made again and again.42
Evidence and legal theory
Thayer and Wigmore provided the starting point for most of my subsequent work on Evidence. I built on their ideas and developed them in a number of ways. However, I deviated from them in some key respects: I broadened the focus from contested jury trials to a total process model of litigation and then to a consideration of evidence in other contexts. This flowed from my concern with standpoint and the idea that there are many kinds of participants in legal processes who are concerned with evidence in addition to judges and juries. They have different vantage points, roles, concerns, goals, skills and data. There are also different kinds of observers with analogous concerns, in particular various types of historians, especially those whose primary concern is what happened in particular past events (in short with historical fact-determination rather than explanation or generalisation).43
Another deviation from Thayer and Wigmore was to consider some alternatives to the epistemological and logical assumptions which were rooted in a particular cognitivist tradition of informal logic exemplified by Francis Bacon, John Stuart Mill and Stanley Jevons, and carried on in recent times by Stephen Toulmin, Jonathan Cohen and Douglas Walton. While often working within that tradition myself, I also considered some challenges to aspects of it exemplified by various philosophical sceptics, historiographers, probabilists (Pascalians, especially Bayesians), holists, narratologists and post-modernists.44 This aspect of my work could be carried much further, but I concluded that Wigmore’s assumptions were rooted in a robust tradition within which I could work for some specific purposes and which fits some models of ‘best practice’ for judicial and practitioners’ practical reasoning. I shall not elaborate on this here.45
Some of the ideas that I had developed in relation to standpoint, process thinking, conceptual analysis and rationality were applied and refined in my studies of Evidence. I also used ideal types to help to dig out the stable but largely unarticulated working assumptions of Evidence scholars and to reveal the extraordinary degree of consensus underlying two centuries of Evidence scholarship which I labelled ‘the Rationalist Tradition’.46
There is an intimate relationship between Evidence and Legal Theory. I have already indicated how the gravitational pull of doctrine both impoverished and distorted Evidence scholarship and marginalised the field within the discipline of Law. Similarly, analytical jurists have paid relatively little attention to the connections between Evidence and Legal Theory. Theorising about evidence in law inevitably involves philosophical questions about epistemology, epistemological scepticism, inferential reasoning, proof and probabilities that had generally fallen outside the sphere of mainstream Jurisprudence. The similarities and differences between historical and legal enquiries about particular past events were especially interesting. Less obvious was the role of narrative in relation to both types of question and the complex relations between narrative and argument in rational and other methods of persuasion.47 One outcome is that relations between these various kinds of reasonings are not adequately explored.48 Basic concepts in the subject of Evidence, such as relevance, materiality, probative force, probability, credibility and presumptions, have received rather uneven attention from analytical jurists. As we saw in Chapter 10, nearly all discussions of legal reasoning and interpretation concentrate on questions of law in hard cases, with little or no reference either to questions of fact and more generally to reasoning and rationality in other legal contexts such as investigation, negotiation and sanctioning.
Studying Evidence opened up for me a whole agenda of relatively neglected theoretical issues that belong to legal theory. These are not only interesting in themselves, but also can cast new light on traditional topics in Jurisprudence, such as the similarities and differences between types of reasoning; concepts such as cogency, weight and relevance in various contexts; varieties of scepticism; and many empirical questions in Psychology and Sociology.49
My inaugural lecture at UCL in 1983, about ten years into this project, was entitled ‘Evidence and Legal Theory’.50 This was an attempt to structure theoretical aspects of Evidence and Proof under the main ‘jobs of Jurisprudence’.51 I resisted the urge to call for a Brand New Theory of Evidence for the Modern Age, but suggested that one could map a number of related lines of enquiry under the organising concept of ‘information in litigation’ instead of ‘judicial evidence’.52 Later I developed some ideas about Evidence as a multidisciplinary field, involving many perspectives, specialisms and practical applications. With Philip Dawid, David Schum and others this was eventually developed into two further projects, including what seemed to be an ambitious programme at UCL that turned out not to be ambitious enough, as I shall relate in Chapter 20.
I have been criticised by Denis Galligan, among others, for producing what they see as unmanageable agendas:
Twining seems to be suggesting [that] one is precluded from entering the arena without first mastering – in addition to the law and practice of evidence – the philosophy of knowledge and logic, moral and political theory, probability theory, psychology, ethnomethodology, and statistics – to name but a few pertinent disciplines. All of course are relevant to evidence, just as they are relevant to any area of social or legal enquiry; but it does not mean that all have to be merged into one … it is a mistake to think that broad generalisation of an interdisciplinary kind is a substitute for close analysis of a selective kind.53
This reaction is understandable. For some of the lines of enquiry I identified seem to be daunting. Galligan and I are in agreement that many disciplines are relevant to the study of evidence, that it is impossible for one individual to master many disciplines and especially that ‘close analysis of a selective kind’ is important – indeed, most of my work on Evidence has been on detailed topics. Furthermore, I am probably more of an anti-reductionist than Galligan.54
This criticism misses three vital points: first, most inferential reasoning in both legal and other contexts is based on ‘common sense’ in the absence of ‘harder’ evidence.55 Secondly, scholarship and enquiry are largely collective enterprises pursued by teams, intellectual communities, allies and combatants who individually are variously equipped. Thirdly, rethinking a field or a sub-discipline, or something narrower is a never-ending task, more often than not collective but, as we have seen in Chapter 12, sometimes it can be significantly advanced by individuals. Such tasks are particularly important when, as in the case of Evidence in Legal Contexts, a field has become stuck in a narrow groove which not only leads to neglect of important questions but also distorts or impoverishes enquiries within that groove. Having devoted the better part of twenty years to ‘rethinking’ one legal ‘field’ as a case study of broadening our discipline, I may not have achieved much more than releasing some hares, most of which I have not been able to pursue very far or at all.
Teaching: tough, but fun
In collaboration with Terry Anderson, and later David Schum, Philip Dawid, Christopher Allen and others, I taught ‘Wigmorean analysis’ for over forty years and together we modified it in some significant respects. Although there were other aspects, especially to do with story-telling, we focused mainly on teaching our students to master some basic skills of constructing, reconstructing and criticising binary arguments based on evidence, especially mixed masses of evidence in complex cases.57 The centre-piece was ‘the chart method’ which can be summarised as follows:
Wigmore’s ‘chart method’ is a specific set of techniques for analysing a complex body of evidence. In respect of a given case or disputed issue of fact, all of the data that are relevant and potentially usable in an argument for or against a particular conclusion (‘the ultimate probandum’) are analysed into simple propositions that are incorporated in a ‘key list’ of propositions. The relations between all the propositions on the key list are then represented in charted form using a prescribed set of symbols, so that the end-product is a chart or set of charts of a (typically complex) argument. The method is like chronological tables, indexes, stories, and other devices in that it is useful for ‘marshalling’ or ‘managing’ complex bodies of data so that they can be considered as a whole; it differs from these in that the organising principle is the logical relationships between propositions in an argument rather than time sequence, narrative coherence, source, alphabetical order, or other taxonomy.58 The method is also useful for identifying strong or weak points in an argument and subjecting these key points to rigorous, detailed, ‘microscopic’ analysis.59
A partial illustration of the Chart Method
The illustration that follows assumes that the ultimate probandum is that ‘X murdered Y’ or, stated more formally, that ‘(A) Y is dead, (B) Y died as the result of an unlawful act, (C) it was X who committed the unlawful act that caused Y’s death and (D) X intended (i) to commit the act and (ii) thereby to cause Y’s death.’ The coroner’s report and observations at the scene satisfy all concerned that ‘Y died at approximately 4:45 p.m. on 1 January in his house as the result of an unlawful act committed by another.’ The following key list and chart analyse five testimonial assertions and related inferences that the analyst claims are relevant to the penultimate probandum: ‘It was X who committed the unlawful act that caused Y’s death.’
The key list
1. X was in Y’s house at 4:45 p.m. on 1 January.
2. X entered Y’s house at 4:30 p.m. on 1 January.
3. W1 saw X enter Y’s house at 4:30 p.m. on 1 January.
4. WI: I saw X enter Y’s house at 4:30 p.m. on 1 January as I was walking on the sidewalk across the street.
5. X left Y’s house at 5:00 p.m. on 1 January.
6. W3 saw X leave Y’s house at 5:00 p.m. on 1 January.
7. W3: I saw X leave Y’s house at 5:00 p.m. on 1 January.
8. X was not at Y’s house on 1 January.
9. X did not enter or leave Y’s house on 1 January.
10. X: I never went to Y’s house on 1 January.
11. X was at her office at 4:45 p.m. on 1 January.
12. X was working at her office from 9:00 a.m. to 5:00 p.m. on 1 January.
13. X: I was working at my office from 9:00 a.m. to 5:00 p.m. on 1 January.
14. A claimed eyewitness identification by a pedestrian walking on
the other side of the street is doubtful.
15. It may be someone other than X whom W1 saw enter Y’s house.
16. The sun had set before 5:00 p.m. on 1 January.
17. A claimed eyewitness identification made after the sun has set is doubtful.
18. It may have been someone other than X whom W3 saw leave Y’s house.
19. W2 saw X enter Y’s house at 4:30 p.m. on 1 January.
20. W2: I saw X enter Y’s house at 4:30 p.m. on 1 January.
21. X’s testimony should not be accepted.
22. X is lying about her actions and whereabouts on 1 January.
23. A person accused of a crime has a strong motive to fabricate testimony that might exonerate her.
24. X is the accused in this case.
25. X was probably not in her office on 1 January.
26. 1 January is New Year’s Day and a legal holiday in this jurisdiction.
27. Few people go to their office and work all day on New Year’s Day in this area.
A = assertion; E = explanation; R = rival; and D = denial. Note that a defendant becomes a ‘proponent’ of rival and denial assertions, and thus the prosecutor may use the process of ‘opponent’s’ explanation to undermine.
Over the years Anderson, Schum and I refined, simplified and extended Wigmore’s rather ponderous approach in several ways and now refer to ours as ‘Modified Wigmorean Analysis’ (MWA).60 There have been some misunderstandings about MWA. First, there is still a mistaken view that ‘the chart method’ or ‘modified Wigmorean analysis’ involves an unwieldy, over-elaborate, difficult, set of skills that is of limited use to practitioners.61 This mistake is usually due to a confusion between the complexity of the method and the complexity of the evidence. The general idea is simple and quickly learned; like any technique, to apply it skilfully takes longer; it is mainly useful in dealing with complex mixed masses of evidence. With a simple protocol it can be applied easily to routine cases or to test whether a seemingly simple case is more complicated than appears on the surface.
On the basis of years of experience, we have shown that the approach is within the reach of undergraduate law students who can master the basics for simpler applications in two–three weeks (e.g. at the start of a traditional course on the Law of Evidence). One of MWA’s most important uses is marshalling mixed masses of potential evidence into a structured argument. Most of our teaching has focused on quite impressive mastery of the basic approach in complex cases by third-year students or postgraduates in six–eight weeks.62 Many of our former students have reported that they have found the approach of value in practice in both routine and complex cases. This is hardly surprising because the method is a semi-formalisation of best practice.
Secondly, this is another prime example of the continuing influence of the doctrinal tradition. The term ‘legal method’, along with ‘legal reasoning’ is typically restricted to argumentation and analysis of questions of law.63 As Frank pointed out, in legal practice questions of fact and problems of fact-determination are far more common in adjudication for judges, jurors and others. That applies even more strongly to other events and decisions within a total process model of litigation and to practical decision-making in other contexts. By treating the Law of Evidence as co-extensive with the subject of Evidence in Law, scholars, teachers, trainers and even practitioners have almost completely marginalised what Wigmore called ‘the Logic of Proof’. Symbolic of this neglect is the occasion when I found that a course on training detectives focused on the Law of Evidence, with instructors seriously opining that ‘logic’ was too ‘academic’ for them. But surely Sherlock Holmes is the patron saint of both investigators and evidence scholars.
By 1995–7 I had completed several books on Evidence and I was turning my attention to Globalisation and Law. My main ideas are to be found in Rethinking Evidence and Analysis of Evidence. Until 2012 I continued to teach Analysis of Evidence, mainly MWA, at both UCL and Miami, occasionally elsewhere. Dave Schum also taught it to students in several disciplines, including law. He also trained intelligence analysts. This is the kind of teaching that I have most enjoyed in my career and, on the whole, I think that I steadily improved. Co-teaching with a combative trial lawyer who was also a disciple of Llewellyn and a close friend was a constant pleasure.64 Dave Schum and Philip Dawid added a multidisciplinary perspective.65 Learning to master the basic techniques is tough, involving exercises on increasingly complex material. But it should also be fun. The raw material is very rich: not only alleged miscarriages of justice, other causes célèbres, but also texts taken from the Bible (Solomon and the Baby), literature, archaeology, intelligence analysis and so on. In addition, I have used other neglected materials of law study, such as limericks and love letters.66 The students became very engaged with their major exercise, applying MWA to cases or historical puzzles of their choice; they participated in role plays, mock trials and story-telling, with the highlight being the annual Wigmore Days in the Anderson home in Miami and the Twining home in Iffley, when they presented their cases. In Miami, they were criticised and guided by ‘alumni’ of the course. They seemed to enjoy it. The most rewarding aspect was how skilled they became after a few weeks of drilling.67
