Understanding Relevance in Causal and Epistemological terms

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UNDERSTANDING RELEVANCE

IN CAUSAL AND

EPISTEMOLOGICAL TERMS

University of the Witwatersrand, Johannesburg

Commerce, Law and Management

Bachelor of Laws Candidate

Independent Research Essay LAWS 4042 (Draft Essay)

Supervised by: Professor James Grant


TABLE OF CONTENTS

1. INTRODUCTION………………………………………………………………………3-6

2. ADMISSIBILITY……………………………………………………………………….6-7

PART I: SUBSTANTIVE RELEVANCE

3. WHAT IS THE MEANING OF RELEVANCE?................................................................7

3.1 FUNCTIONALITY AND RELATIONALISM………………………………...8-9

3.2 PROBABILITY………………………………………………………………..9-11

PART II: METHDOLOGICAL RELEVANCE

4. HOW DOES ONE MAKE A RELEVANCY ASSESSMENT?……………………..11-14

4.1 LOGIC, COMMON SENSE AND EXPERIENCE………………………….14-16

4.1 CAUSALITY AND EPISTEMOLOGY……………………………………..16-19

5. CONCLUSION……………………………………………………………………..........19

6. BIBLIOGRAPHY……………………………………………………………………20-25


ABSTRACT

Both at common law and through statute, the fundamental criterion of admissibility is relevance.

Without forgetting that the admissibility of evidence is a matter of law involving not only the

criterion of relevance, but several other ‘policy’ or ‘legal’ considerations as well, this paper

concerns itself with the former only. It is submitted, in this paper, that the legal concept of

relevance consists of a substantive as well as a methodological component. The former relates to

its meaning and substantive content, while the latter relates to the intellectual processes involved

in assessing the relevance of evidence. Ultimately, the thesis which this paper posits is that

relevance is not only substantively relational and functional, as a connector between evidentiary

facts and the facts in issue which they seek to prove, but it is also a methodological projection of

our expectations to the extent that we rely on our sensory knowledge about Humean causal

relations to reach probabilistic conclusions as to the existence or non-existence of facts in issue

based on inferences drawn from evidentiary facts.

“Might it be suggested that the central act of the legal mind, of judge and lawyer alike, is the conversion of the raw

material of life…into a story that will claim to tell the truth in legal terms?”.1

1. INTRODUCTION

For that most important exercise of ‘fact-finding’ during a trial, there is no better aid for the lawyer

than the rules and theories of evidence. It is after all ‘lawyer’s law’.2 For without the law of

evidence, ploughing through the often complicated, ubiquitous and incomplete set of facts in each

1 James Boyd White cited in Twining W Rethinking Evidence: Exploratory Essays (1994) 219. 2 Ibid 341; see also Paizes A ‘Must we have a theory of proof?: Evidence, Criminal Process and Criminology’ Acta

Juridica (2003) 113 at 113.


case would no doubt even more difficult.3 Being arguably the only area of law that truly concerns

itself with the conundrum of proof,4 it is not surprising that Paizes would remark as follows:

“The law of evidence is well known for its power to both fascinate and to tease…few subjects that are so important a

part of the practical workings of a legal system can, at the same time, remain so mysterious, enigmatic and elusive”.5

Fortunately, according to Paizes:

“Judges, of course, understand this perplexing subject. They know what evidence to admit or exclude, they appreciate

the dangers presented by certain classes of evidence and are careful to give them their appropriate weight; and they

are familiar with the processes of reasoning that link evidence with valid conclusions”.6

Furthermore, although, it is submitted, the law of evidence has always been and will always be

fundamentally concerned with the phenomenon and processes of proof, Wigmore rightly points

out that this has not always been the main focus.7 ‘The study of the principles of evidence’, he

says, ‘for a lawyer, falls into two distinct parts. One is Proof in the general sense,--the part

concerned with the ratiocinative process of contentious persuasion,-mind to mind, counsel to juror,

each partisan seeking to move the mind of the tribunal. The other part is Admissibility,-the

procedural rules devised by law, and based on litigious experience and tradition, to guard the

tribunal (particularly the jury) against erroneous persuasion. Hitherto, the latter has loomed largest

in our formal studies,-has, in fact, monopolized them; while the former, virtually ignored, has been

left to the chances of later acquisition, casual and emphatic, in the course of practice’.8 Without

derogating from the truth of Wigmore’s assertion, it is submitted that it is better to understand all

of evidence to be fundamentally concerned with the proof of facts, while the ‘procedural rules’

merely attempt to assist the trier of fact navigate their way to this ultimate destination.9 In this way,

3 Eggleston R Evidence, Proof and Probability (1978) 1-2. 4 Keane A The Modern Law of Evidence 5th ed (2000) 1; Van der Merwe SE ‘An introduction to the History and

Theory of the Law of Evidence’ in Schwikkard PJ, Van der Merwe SE et al Principles of Evidence 3rd ed (2008) 1-

2. 5 Paizes A ‘Chasing Shadows: Exploring the Meaning, Function and Incidence of the Onus of Proof in the South

African Law’ (1999) 116 SALJ 531 at 531. 6 Paizes A ‘Advances in the Law of Evidence: Reflections on Reading the Fourth Edition of LH Hoffman and D

Zeffert’s The South African Law of Evidence’ (1989) 106 SALJ 472 at 472. 7 Wigmore JH ‘The Problem of Proof’ (1913) 8 Illinois Law Review 77 at 77. 8 Ibid. 9 It is in this spirit that Paizes remarks that: “we know what we want to achieve, and we make sure that our

evidentiary rules deliver the results we need”. (see Paizes (note 2) above 113).


admissibility becomes nothing more than a ‘halfway-house’ towards the desired destination of

proof.

In the same vein, Eggleston makes the point that the adjudication process consists of a series of

ancillary or preliminary decisions, all of which are important steps towards the rendering of the

final judgment.10 The decision of admitting or excluding evidence is one such crucial ancillary or

preliminary decision. This paper is particularly concerned with the legal concept of relevance as a

criterion of admissibility.11 It is immediately accepted at this early stage that relevance is not all

there is to admissibility;12 for admissibility is, unlike relevance, which is entirely a matter of logic,

probability and experience,13 a question of law14 involving ‘trial concerns’15 such as: ‘prejudice

cause to one of the parties’,16 the proliferation of multiple collateral issues,17 the cause of undue

delay and the incurrence of unnecessary expenses.18 However, there are no doubt instances where

the probative value of a piece of evidence may outweigh any such trial concerns that may persist

to the extent that such evidence is admitted.19 This is, however, beyond the scope of this paper.

The main concern for this paper is the legal criterion of relevance. In particular, this paper is

concerned with the meaning of the legal concept of relevance and the extent to which knowledge

is relied upon to make assessments as to whether evidence is relevant or not.

This paper is structured in two main parts relating to the substantive and methodological

components of the concept of relevance. After making a few tentative remarks about admissibility

10 Eggleston (note 3) above 5. 11 See Criminal Procedure Act 51 of 1977, s210; Criminal Proceedings Evidence Act 25 of 1965, s2. Relevance was

also the main criterion for the admissibility of evidence at common law: see S v Gokool 1965 3 SA 461 (N) 475G. 12 McEwan opines that: “Logical relevance is a sine qua non admissibility; but it cannot guarantee that the evidence

will be admitted; in fact, on its own it is far from sufficient”. (see McEwan J Evidence and the Adversarial Process:

The Modern Law 2nd ed (1998) 33-4). 13 Michael J and Adler M.J ‘The Trial of an Issue of Fact: I’ (1934) 1224 at 1279. 14 Keane (note 4) above 20. 15 Graham M.H Handbook of Federal Evidence (1981) 181. 16 R v Kumalo & Nkosi 1918 AD 500 504. 17 Delew v Town Council Springs 1945 TPD 128 131. 18 Delew supra 131. 19 For instance, in R v Dhlamini 1960 1 SA 880 (N), the accused was charged with stabbing the complainant. In his

defence, he adduced evidence of him being somewhere else at the time of the stabbing. The prejudicial effect of this

evidence, however, is that it (i.e.: the piece of evidence) suggested that he was busy stabbing someone else at the

time of the stabbing of the accused. However, the court nevertheless admitted the evidence on the basis that its

probative value outweighed its prejudicial effect (at 881A-C).


in general, the first part begins with a discussion about the meaning and substantive content of the

legal concept of relevance. In this sense, the paper critically analyses the idea of relevance as a

substantive proposition. At the heart of part I, sits the question: ‘what is relevance?’ It is also

submitted that the legal concept of relevance has a methodological component, a discussion of

which follows in the second part of this paper. In this regard, a response to the question as to

precisely how one undertakes an assessment of relevancy within the law of evidence is explored

in the second part. It is also in part II of this paper that the extent to which assessments of relevancy

are dependent on logic and knowledge. Ultimately, the standard theoretical proposition made by

this paper is that relevance, in the context of the law of evidence, is nothing more than a projection

of our experiences or knowledge tied together by the strings of ‘rationalist reason’.

1. ADMISSIBILITY

To begin with, it is useful to have regard to the following remarks made by Murphy:

“Because the purpose of evidence is to establish the probability of facts upon which the success of a party’s case

depends in law, evidence must be confined to the proof of facts which are required for that purpose”.20

Thus, as a matter of legal policy, only evidentiary facts21 that are necessary for the success of either

party’s case or for the proof of certain facts in issue deserve consideration in a trial.22

Secondly, it is important to note that decisions on whether to admit or exclude evidence are

tentative and forward-looking in the sense that the trier of fact pronounces upon the potential

probative weight of evidentiary facts.23 Thus, when the trier of fact get around to evaluating the

evidence, he or she will then make a finding as to the final probative weight of the evidence.24

Thus, at the admissibility stage, the trier of fact makes a ‘rough and ready estimate’ as to how

potentially valuable, in probative terms, evidence will be if admitted.25 It would, therefore, mean

20 Murphy P A Practical Approach to Evidence 10 ed (2008) 25. 21 Throughout this paper, the term ‘evidentiary fact(s)’ will be used to refer to pieces of evidence used to prove

certain facts in issue. In contrast, given that both fact probanda as well as facta probantia may be in dispute, the

term ‘fact in issue’ will be used to refer to any fact that is sought to be proven through the adduction of evidentiary

facts; see Schwikkard, Van der Merwe et al (note 4) above 47. 22 Thayer J.B A Preliminary Treatise on Evidence at the Common Law (1989) 530; see also Lempert R.O and

Saltzburg S.A A Modern Approach to Evidence: Text, Problems, Transcripts and Cases (1978) 140-1. 23 Zuckerman A.A.S The Principles of Criminal Evidence Clarendon Press (1989) 51. 24 See Stellenbosch Farmers’ Winery Group Ltd v Martell et Cie 2003 1 SA 11 (SCA) [5]. 25 Zuckerman (note 23) above 51.


that the kind or level of proof with which one is concerned at the admissibility stage is tentative,

probabilistic and forward-looking. For this reason, it is submitted that proof at the admissibility

stage is certainly not as strict as at the stage at which the admitted evidence is evaluated. Inevitably,

the assessment of relevancy should also be understood in this particular light.

PART I: SUBSTANTIVE RELEVANCE

3. WHAT IS THE MEANING OF RELEVANCE?

The practical exercise of identifying and contrasting apples and pears or comparing like terms in

a mathematical equation is far easier than describing in abstracto why apples and pears cannot be

compared or why is it that unlike terms cannot be added or subtracted in a mathematical equation.

Similarly, many would find it more cumbersome to explain their choices than they would to make

such choices. This may readily be observed from the following dictum by Tredgold J, who held

that:

“Now, I must remember at this juncture that I am not concerned with the weight which may be attached to this

evidence. I am simply concerned with its admissibility, and I have no doubt whatsoever that it is legally admissible

and that there is nothing improper in the Crown leading this evidence. It is quite clear on the authorities which have

been quoted that the behaviour of the accused subsequent to the allegations being made against him is relevant and

is admissible in evidence”.26

Thus, it is unsurprising that for many lawyers, ‘it [that is, the concept of relevance] is certainly

easier to identify in practice than to describe in the abstract’.27 Conversely, this paper ambitiously

attempts to embark upon the undoubtedly cumbersome exercise of articulating in abstracto the

substantive proposition of relevance in the context of the law of evidence. For if the purpose of

practice is to teach one how to do something, then it is equally important for one to know and

understand what it is exactly they are doing at each point.28

26 R v C 1949 2 SA 438 (SR) 439 (emphasis added). 27 Schwikkard, Van der Merwe et al (note 4) above 46. 28 See Edwards H.T ‘The Growing Disjuncture Between Legal Education and the Legal Profession’ (1992) 91

Michigan Law Review 34.


3.1 FUNCTIONALITY AND RELATIONALISM

At the heart of the idea of relevance lies the concept of a relationship between at least two distinct

aspects.29 Thus, relevance is, at least, relational in both ordinary and legal contexts. Similarly,

albeit rather controversially, Willis uses the word ‘relevance’ synonymously with the word

‘connection’.30 In this sense, the concept of relevance is a useful tool to not only compare two

separate things, but it also assists one in understanding the connection or relationship between

things which are comparable.

In the ordinary sense of the word, Gorayska and Lindsay describe relevance in the following terms:

“it denotes the relation between means and ends. The functional relation captured by the ordinary sense of ‘relevance’

is objective: what is relevant to what, is constrained by the widely observable relational and causal processes of the

universe (inclusive of enablements, triggers, achievements, accomplishments, etc.), which determine the set of all

possible ends and the set of all possible means to achieve those ends. The relation captured by the ordinary sense of

‘relevance’ is transitive: means and ends form interdependency chains such that, if X is an observed means to an end

Y, and Y is an observed means to an end Z, then X must also be a means to the end Z”.31

Similarly, Twining described the legal concept of relevance as entailing ‘the relation between the

factum probans and factum probandum’.32

Therefore, relevance, as a substantive legal proposition, consists in the functional relation between

evidentiary facts, being the means, and the facts in issue, which would be the ends.

A further gloss was added by the renowned Sir James Fitzjames Stephen, who described the legal

concept of relevance in the following manner:

29 See Morgan E.M Basic Problems of Evidence (1961) 183-4; Maguire J.M Evidence, Common Sense and Common

Law (2009) 110-111. 30 Willis J.D Garrow and Willis’s Principles of the Law of Evidence 6th ed (1973) 60. 31 Gorayska B and Lindsay R ‘The Roots of Relevance’ (1993) 19 Journal of Pragmatics 301 at 302. 32 Twining W Theories of Evidence: Bentham & Wigmore (1985) 29. However, given that facta probantia may also

be in issue and thus sought to be proved, it is not entirely correct to describe relevance as relating facta probanda

and facta probantia, see note 21 above.


“any two facts to which it is applied are so related to each other that according to the common course events one either

taken by itself or in connection with other facts proves or renders probable the past, present, or future existence or

non-existence of the other”.33

It follows, therefore, that relevance is not only relational and functional, but it is also probabilistic

in the sense that what in fact connects evidentiary facts and the facts in issue which they attempt

to prove is probability. That is, the former serves the purpose of rendering the latter more or less

probable.

3.2 PROBABILITY

If proof creates certainty, then uncertainty and proof must be two sides of the same coin. This is

to say, where uncertainty ends, certainty, by way of proof, must surely begin. It further follows

that if factual and legal findings are only made at the latter stages of a trial, then much of the trial

will often be characterised by uncertainty and dispute. This was in fact the point made by Eggleston

when he said the following:

“The legal system is concerned with making decisions, and decisions must often be made in a situation of uncertainty,

either as to what has happened in the past, or as to what is going to happen in the future. We are not concerned here

with uncertainty as to legal rules, though this is frequently a matter of anxiety, especially to those who have to make

the decision whether or not to commence proceedings. Our interest is uncertainty as to the facts to which the law must

be applied”.34

Furthermore, Lord Steyn held that the legal concept of relevance necessitated a decision as to

whether evidence is capable of increasing or diminishing the probability of the existence or non-

existence of a particular fact in issue.35 In other jurisdictions, the word ‘tendency’ is used

interchangeably with the word ‘probability’36 and to the extent that they mean the same thing, they

convey the idea that the legal concept of relevance entails an intellectual process of the means or

the evidentiary fact being adduced to render the existence or non-existence of the ends or the fact

in issue to be more or less probable. Put differently, one begins at the position where the existence

or establishment of a particular fact in issue is unknown, in dispute or uncertain. One of the parties

33 Stephen J.F A Digest of the Law of Evidence 11th ed (1930) article 1. This particular formulation was accepted by

Chief Justice Watermayer, as he then was, in R v Katz 1946 AD 71 at 78. 34 Eggleston (note 3) above 3-4. 35 R v Randall [2004] 1 WLR 56 [20]. 36 United States Federal Rules of Evidence of the United States of America, Rule 401.


will often contend that this particular fact in issue does in fact exist and he or she will accordingly

adduce certain evidentiary facts to this effect. Thus, in order to be relevant, the effect of the

evidentiary facts adduced must be to remove the particular fact that is sought to be proven from its

ab initio position of uncertainty to a position where its existence is found to be sufficiently

probable.

Still further, probability is variable and a matter of degree.37 Relevance, which, as noted

immediately above, is probabilistic, is arguably no different.38 Thus, with variability comes the

need for at least some confines within which the probability of the fact that is sought to be proven

should range. It is for this reason that Wigmore contended that all evidence, in order to be logically

relevant, must have a ‘plus value’.39 Similarly, American lawyers often make reference to a certain

‘minimum probative value’ that every piece of evidence must attain in order to be found to be

sufficiently relevant to be admitted.40 The same sentiment appears to persist among South African

scholars given that, for instance, Zeffert and Paizes hold the view that ‘evidence must be

sufficiently relevant, that is to say, of sufficient value as proof in each case, to warrant its

reception’.41 Whether or not relevance or probability is a matter of degree is a controversial

question that is beyond the scope of this paper, however, what is clear is that there is a particular

unspecified threshold that the relevance, and by extension the probability, of evidence must meet.

If it is indeed correct to assert the prevalence of a certain unspecified minimum threshold of

relevance in South African law, then it would follow that evidentiary facts, in order to be

sufficiently relevant to be admitted, must have relevance that ranges between the unspecified

minimum threshold, on the one hand, and most optimum level of relevance possible. Given that

37 See generally, Eggleston (note 3) above. 38 Zeffert D.T and Paizes A.P The South African Law of Evidence 2nd ed Lexis Nexus (2009) 239-240; see also

Hoffman L.H ‘Those Dogs Again’ (1974) 91 SALJ 237 at 238. However, relevance has been argued to be invariable

and to be separate, in this respect, from probability, which is variable and a matter of degree: see Michael and Adler

(note 13) above 1284; Trautman H.L ‘Logical or Legal Relevance: A Conflict in Theory’ (1951-1952) 5 Vanderbilt

Law Review 385 at 389. 39 Wigmore J.H Evidence in Trials at Common Law 3rd ed (1940) 409-410. For criticism of this approach, see

Lempert and Saltzburg (note 22) above 145-6. 40 See Leonard D.P ‘Minimal Probative Value and the Failure of Good Sense’ (1997-1998) 34 Houston Law Review

89 at 89-101; Trautman (note 38) above 388-392; compare with Wigmore J.H Evidence in Trials at Common Law

volume 1A (revised by Peter Tillers) (1983) 1030-1. 41 Zeffert D.T and Paizes A Essential Evidence (2010) 75.


relevance is probabilistic, it is necessary to further assert that the level at which an evidentiary fact

renders the existence or non-existence of a particular fact in issue probable should equally fall

within the same range. It is useful to think of this range using Hoexter’s idea is an ‘area of

legitimate diversity’, notwithstanding the fact that she used the idea in quite a different context.42

According to this particular idea, it would be permissible for relevant evidentiary facts to differ in

the extent to which they are relevant to the facts they attempt to prove, so long as they range

somewhere between the above-mentioned unspecified threshold of relevance and the most optimal

point of relevance. This range would be the ‘area of legitimate diversity’. The same reasoning

would accordingly apply to the probability aspect of the substantive relevance proposition.

There are thus three legs to the substantive proposition of relevance, namely: (a) the legal notion

of relevance implies a functional relationship between evidentiary facts, being the means, and facts

in issue, which would be the ends; (b) where the role of the former is to render the existence or

non-existence of the latter probable; (c) at the sufficient level to range within the required area of

legitimate diversity.

PART II: METHODOLOGICAL RELEVANCE

4. HOW DOES ONE MAKE A RELEVANCY ASSESSMENT?

At this point of the paper, the concern shifts to the intellectual processes involved in making an

assessment of the relevance of an evidentiary fact. It is the question as to how one arrives at a

judgment or finding that something is relevant or not that is now addressed. The task remains

difficult, as was the case in part 1 of this paper, because the discussion of the methodological

proposition of relevance will continue to be fairly abstract.

As has already been pointed out above, trials are often characterised by uncertainty and dispute. It

is for this reason that the adversaries involved in a case, in an effort to persuade the trier of fact,

narrate their respective versions to the court.43 Much of the uncertainty rests on the disputed facts

in issue which are sought to be proved through the adduction of certain evidentiary facts. It follows,

42 Hoexter C ‘The Future of Judicial Review in South African Administrative Law’ (2000) 117 SALJ 484 at 510. 43 Twining (note 1) above 220-8.


therefore, that one of the most remarkable features of the relevancy assessment is the usage of

certain intellectual processes to transcend from a position of uncertainty to one of certainty or at

least ‘probability’. For although we might know and be certain about the fact that a tracker dog

identified a person, apparently based on his or her scent, to be a perpetrator of a particular crime,

we in fact do not know the identity of the person who allegedly committed the crime in question.44

Similarly, we may have no knowledge of or certainty as to whether or not one person raped

another, the evidentiary fact that a clinical psychologist expresses the expert opinion that the latter

was in fact raped by the former is something which we know and which is adduced to prove that

which we do not know.45

It certainly begs the question as to how we can ever justify the knowledge that we obtain about the

existence or non-existence of certain facts in issue through the fact-finding process. What makes

things even more suspect is the fact that all we have as a source of acquiring this knowledge is the

evidentiary facts adduced to prove the particular fact in issue. However, South Africa’s affiliation

to the English rationalist tradition46 negates any such epistemological crises of Descartian

skepticism.47 For it is not whether we ever get to know or be certain about the existence or non-

existence of the facts in issue that are sought to be proven because, according to the many

‘epistemological assumptions’48 that the rationalist tradition makes, we in fact do end up having

such knowledge,49 the question is rather how we are able to acquire the knowledge. Furthermore,

given that the assessment of relevancy is concerned not with perfect certainty or truth, but rather

with approximations and probabilities,50 knowledge about the existence or non-existence of facts

in issue need not be that such facts in fact, and with precise certainty, exist or not. Instead, we are

only required to know whether the evidentiary facts presented render the existence or non-

existence of the facts sought to be proved more or less probable.

44 These particular facts resemble those in the cases of R v Trupedo 1920 AD 58; and S v Shabalala 1986 (4) SA 734

(A). 45 These facts resemble the defamation case of Holtzhauzen v Roodt 1997 4 SA 766 (W). 46 For an elaborate discussion of this particular tradition see Twining (note 1) above 32-91; and for a critique see

Twining (note 32) above 13-8. 47 René Descart begins the First Meditations with a sense of doubt or skepticism about everything that he claims to

know by asserting the need to ‘demolish everything completely and start again from the foundations’, see Descart R

Meditations on First Philosophy (edited by Andrew Bailey) (2013) 135-146. 48 Twining (note 32) above 13-4. 49 Lempert and Saltzburg (note 22) above 140-1. 50 Wigmore (note 40) above 1026.


The only known epistemological technique of transcending, without more, from a known fact to

an unknown fact is inferential reasoning.51 Indeed, Michael and Adler remark that:

“Although proof usually begins with the introduction of evidence, evidence by itself is always insufficient to resolve

an issue of fact. A process of inference, in which the admitted propositions of real and testimonial evidence are ultimate

probantia, must intervene”.52

Speaking more generally about inferential reasoning, Robinson similarly holds the following view:

‘Inference, they say, involves novelty, movement of thought from what we know to what we do not know. Thus,

inference is held to be a movement of thought from old facts to new facts. It is the bridge which the mind builds across

the chasm which separates the realm of human knowledge from the realm of human ignorance. “What we know”, said

Laplace, “is little, but what we do not know is immense”, and inference is the intellectual process by which we add to

the little we know by biting off bits from the immensity of the universe which we do not know’.53

Since its approval by Lord Wright,54 the method of inference has widely been accepted as the

standard methodology to be employed in every relevancy assessment.55 It was in fact Dove-Wilson

JP who expressed his understanding of relevance in the following terms:

“Now facts relevant to the issue may always be proved, and any facts are so relevant if from their

existence inferences may properly be drawn as to the existence of the fact in issue”.56

It has, thus, become trite that the probability of the existence or non-existence of a fact in issue is

inferred from the evidentiary facts adduced to prove it.57 It follows that the assessment of whether

51 It should be noted that the type of inference drawn in the relevancy assessment is markedly different from that

popularly drawn from circumstantial evidence. In the latter instance, two inferences are drawn at two distinct tires,

namely: to establish credibility and to establish whether the circumstantial evidentiary facts adduced supports the

overall conclusion that is advanced by the party adducing such evidence (see Zeffert and Paizes (note 38) above 99).

On the other hand, the inference relating to relevance is general, relational and functional applying to all types of

evidence, including circumstantial evidence. 52 Michael and Adler (note 13) above 1269. 53 Robinson D.S The Principles of Reasoning: An Introduction to Logic and Scientific Method 2nd ed (1930) 107-

108. 54 Caswell v Powell Duffryn Associated Collieries Ltd [1939] All ER 722 (HL) 733G. 55 AA Onderlinge Assuransie Assosiasie Bpk v De Beer 1982 (2) SA 603 (A) 620; Motor Vehicle Assurance Fund v

Dabuzane 1984 (1) SA 700 (A) 706; S v Mtsweni 1985 (1) SA 590 (A) 593E-F; Katz v Katz [2004] 4 All SA 545 (C)

565; Mather v S [1998] 3 All SA 92 (O) 95; Skilya Property Investments (Pty) Ltd v Lloyds of London 2002 (3) SA

765 (T) 780H-781A. 56 R v Mpanza 1915 AD 348 352-3. 57 Wigmore opines that: “No amount of evidence can establish conclusively or with certainty that any matter of fact

does or does not exist. Knowledge of facts is always a matter of probabilities. We may acquire knowledge of matters

of fact by drawing inferences from evidence, but these inferences can only alter the probability that some fact does


or not a particular evidentiary fact is relevant entails the drawing of an inference from it as to the

probability of the existence or non-existence of a particular fact in issue. Being acquainted with

the method of inference as the standard methodology for the assessment of relevance is but only

the first step of understanding the methodological proposition of relevance. For several complex

methodological questions remain unanswered, namely: when or under what circumstances is one

permitted to infer from evidentiary fact A that fact B is likely to exist or not? To what degree of

probability is the inference drawn permitted to carry evidentiary fact A towards proving fact B?

What is the nature of the inference that one is permitted to draw? For instance, would one be

permitted to infer from the fact that it rained heavily on the previous day that the puddles that can

be seen on the road today were caused thereby? Similarly, is it permissible to infer that a person

had intention to shoot and kill another from the evidentiary fact that both persons were allegedly

heard arguing before the death of the latter?58

4.1 LOGIC, COMMON SENSE AND EXPERIENCE

After posing the very first of the questions posed immediately above, Zeffert and Paizes gave the

following response:

“That defies definition and it would, perhaps, be best merely to say that relevance is determined by reason and common

sense”.59

Furthermore, it is also universally accepted that relevancy assessments are matters of logic and

experience lying outside the law.60 In particular, Graham remarks that when making assessments

of relevance the trier of fact must draw from his or her everyday experience of human behaviour.61

It is, therefore, submitted that all of the methodological questions posed immediately above are to

be answered with reference to logic and the trier of fact’s everyday experience of human behaviour

or does not exist and can never establish with certainty that some fact does or does not exist” (see Wigmore (note 40

above) 1030). 58 See Grant J ‘Is Pistorius guilty of murder?’ in Criminal Law of South Africa, posted on 12 July 2014 (blog can be

accessed at: http://criminallawza.net/2014/07/12/205/) (last accessed: 19 July 2014). 59 Zeffert and Paizes (note 38) above 238. 60 See R v Matthews 1960 (1) SA 752 (A) 758; Van den Berg v Coopers & Lybrand Trust (Pty) Ltd 2001 (2) SA 242

(SCA) 26; National Education, Health and Allied Workers Union v Tsatsi [2006] 1 All SA 583 (SCA) 12; DPP v

Boardman [1975] AC 421 (HL); DPP v Kilburn 1973 AC 729 756; United States v Hickey, 596 F.2d 1082, 1089 (1st

Circuit. 1979), cert. denied 444 U.S 853, 100 S.Ct 107, 62 L.Ed.2d 70; United States v Schiff, 612 F.2d 73, 80 (2nd

Circuit. 1979). 61 Graham (note 15) above 147-8.

http://criminallawza.net/2014/07/12/205/


in the ordinary course. It is, however, important to make a few remarks about each of these

nebulous concepts.

Notwithstanding the resounding and universal reference to logic when many scholars and judges

are attempting to explain the methodological proposition of relevance, we are reminded by Zeffert

and Paizes that the relevancy assessment does not require us to ‘act like philosophers or

logicians’.62 This particular sentiment is perhaps far more persistent in practice than in modern

scholarship on evidence.63 However, this coupled with Tribe’s famous scathing text on the

inappropriateness of the usage of mathematical or scientific probability theories64 such as: the

Bayes theorem,65 frequentist theories,66 Baconian theories,67 Pascalian theories,68 aleatory or

stochastic theories and several other theories alike69 has had a significant chilling effect on many

judges around the world.70

For although we are not heading back to the days of the infamous Judge Bridlegoose, who

admittedly decided cases by throwing a pair of dice,71 all the controversies that surround

mathematics and scientific probability theories in the context of evidence equally propel the law

of evidence and the science of proof away from the latter direction. No doubt, one of the most

important foundations of persuasion is certainty, reliability and understanding. This is particularly

observable from judges, on several occasions, excluding tracker-dog evidence simply because it

62 Zeffert and Paizes (note 41) above 75; see also Thayer (note 22) above 269. 63 See Raeder M.S ‘Irrelevancy: It’s all in the eyes of the beholder’ (1997-1998) 34 Houston Law Review 103. 64 Tribe L.H ‘Trial Mathematics: Precision and Ritual in the Trial Process’ (1971) 84 Harvard Law Review 1329 at

1329-1393, see particularly 1393. For a critique of Tribe, see Finkelstein M.O and Fairley W ‘The Continuing

Debate over Mathematics in the Law of Evidence: A Comment on “Trial by Mathematics”’ (1971) 84 Harvard Law

Review 1801 at 1801-1809; see also Eggleston (note 3) above 23-4. 65 Ibid 1351-1353. The Bayes Theorem is the basis of a general probability theory known as ‘subjectivist or

personalist probability theory’, see Wigmore (note 40) 1049 and 1056. 66 For criticism of these theories, see Wigmore (note 40) 1049-1050. 67 Cohen L.J The Probable and the Provable (1977); Cohen L.J ‘The Logic of Proof’ (1980) Criminal Law Review

91. Eggleston rejects the applicability of Baconian theories in the realm of forensic fact-finding, see Eggleston R

‘The Philosophy of Proof’ (1991) 65 Australian Law Journal 130 at 148. 68 See Zeffert and Paizes (note 38) above 36. 69 See Schum D.A ‘'Probability and the Processes of Discovery, Proof and Choice' (1966) 66 Boston University Law

Review 825. 70 See Rader M.S (note 63) above 105. 71 Gest J.M ‘The Trial of Bridlegoose: As Reported by Francois Rabelais’ (1937) 71 United States Law Review 503.


lay ‘in the region of conjecture and uncertainty’.72 The net effect of all of this has been an increased

reliance on ‘everyday experience’ and knowledge in relevancy assessments.

Equally, there remains a degree of uncertainty in the usage of complex types of logic such as the

Aristotelian syllogism,73 which is a tool of deductive logic,74 as well as inductive logic.75 For this

reason, many of the techniques used in formal logic have also not found explicit favour with triers

of fact in the context of the law of evidence.

Thus, the assessment of relevancy has been suggested to be a practical one that is heavily reliant

on simplistic experience of ordinary human behaviour.76 To this extent, the methodological

proposition of relevance is practical and epistemological. On this basis, the central thesis advanced

in this paper is that the legal concept of relevance is a practical projection of one’s knowledge of

the world around them.

4.2 CAUSALITY AND EPISTEMOLOGY

Having established the simplicity and practicality with which the method of inference is to be used

in assessing the relevance of evidentiary facts, it is now appropriate to return to the question as to

how we obtain knowledge of the probability of the existence or non-existence of facts which are

sought to be proven. It is also well beyond doubt that this is in fact what trial are principally about;

that is, learning or acquiring knowledge about the probable facts of the case.77

72 Trupedo supra 63; see also Shabalala supra and R v Kotcho 1918 EDL 104. 73 The syllogism is possibly Aristotle’s greatest contribution to logic. It is a tool of deductive reasoning used to reach

conclusions by drawing inferences from established premises, see Robinson (note 53) above 115-6; see also

Trautman (note 38) above 388-9. 74 While some authors propound the application of deductive logic to the process of drawing inferences (see Michael

and Adler (note 13) above 1269-1272; Trautman (note 38) above 388-9; Sidgwick A Fallacies: A View of Logic

from the Practical Side (1884) cited in Wigmore (note 40) above 983), others suggest that inductive logic is to be

preferred (see Wigmore (note 40) above 982 and 984). However, given the difficulties involved in preserving the

distinction between deductive and inductive logic (see Wigmore (note 40) above 984), it is not surprising that

aspects of both forms of logic are often simultaneously involved in common reasoning. 75 For Hume’s well known critique of induction, see Dicker G Hume’s Epistemology and Metaphysics: An

Introduction (1998) 73-89. 76 See Zeffert and Paizes (note 41) 238. 77 For instance, Michael and Adler remarks that: “The trial is thus not merely a process of proof or a process of

learning, but a dialectical affair in which knowledge is gained and weighed on both sides of the question”, see

Michael and Adler (note 13) above 1305.


Michael and Adler contend that there principally three ways through which we may acquire such

knowledge, namely: through memory, sensory experience or reason.78 The first two sources of

knowledge may be readily dismissed for the following reasons: it is almost invariably not possible

for the trier of fact to rely on his or her sensory experience to find that a certain fact in issue exists

or not due to the fact that he or she was, in almost all cases, not present at the scene of the incident

and thus did not perceive any of what is alleged. Thus, a trier of fact cannot say, for example, ‘I

know that the accused assaulted the complainant yesterday because I was there and I perceived

this happening’. Secondly, for very similar reasons, memory, which is ‘a kind of derivative

knowledge’79 comprising of one’s sensory experiences that have been kept in mental storage, also

cannot be a valid source of such knowledge for the simple reason that the trier of fact will almost

invariably not have perceived any of facts disputed in the case.

This leaves only reason as a possible source of such knowledge and it is submitted that this is

indeed the most likely source. The argument, in this regard, rests on three legs: ‘reason’ is the

hallmark of the English rationalist tradition, to which South Africa’s law of evidence is affiliated.

For it was indeed Twining who described the rationalist tradition in the following manner:

‘epistemology is cognitivist rather than skeptical; a correspondence theory of truth is generally

preferred to a coherence theory of truth; the mode of decision-making is seen as “rational”

contrasted with “irrational” modes such as battle, compurgation, or ordeal’.80

Secondly, a thin layer of empiricism appears to be attached to the foundation of the English

rationalist thought.81 In fact, it is submitted that the rationalist tradition is derived from the

philosophy of English empiricists such as Bacon, Locke and Mill.82 Therefore, ‘no facts about the

world can be established by reasoning independently of experience’.83 However, it is of course not

entirely correct to assert otherwise that all our knowledge is a posteriori because, as Kant, remarks:

“But, though all our knowledge begins with experience, it by no means follows that all arises out of experience. For,

on the contrary, it is quite possible that our empirical knowledge is a compound of that which we receive through

78 Ibid. 79 Wigmore (note 40) above 1028. 80 Twining (note 32) above 16. 81 Macnabb D.G.G David Hume: His Theory of Knowledge and Morality (1966) 40. 82 Zeffert and Paizes (note 41) above 35. 83 Macnabb (note 81) above 40.


impressions, and that which the faculty of cognition supplies from itself (sensuous impressions giving merely the

occasion), an addition which we cannot distinguish from the original element given by sense, till long practice has

made us attentive to, and skilful in separating it”.84

Thirdly, two of the main components of Hume’s theory of epistemology are that (a) knowledge as

to matters of fact that is not based on memory or direct sensory experience is always based on

‘causal relations’, (b) which are not knowable a priori, but only by inference from past

experience.85

If one relies on the argument advanced immediately above, then the conclusion is inevitable: given

that the trier of fact would, in almost all cases, not have directly experienced, through the senses,

the incident that is the subject of the case, he or she will have to form a conclusion based on a

secondary kind of experience. That is, sensory experience of what he or she may know about the

incident or the facts in dispute in the general sense. In other words, in the case where the trier of

fact was not present when the accused allegedly shot and killed another person, he or she (that is,

the trier of fact) would have to form conclusions or draw inferences based on his or her previous

and general sensory experience with or knowledge of guns, ammunition, human behaviour and so

forth. Thus, it is often said that where one cannot rely on direct experience as a source of inferred

knowledge, he or she will have to embark upon a comparison of general ideas.86

Furthermore, this particular mode of inference or reasoning, as a source of knowledge about the

probable existence or non-existence of a particular fact in issue, may, in Humean terms, be

described as being causal87 because the conclusion reached or the knowledge that eventuates from

the drawing of such an inference is based on the sensory knowledge that one has of how things

generally relate causally. For instance, if one knows, through previous sensory experience, that a

person’s fingerprints will be found on a stolen car only if the person came into physical contact

84 Kant I Critique of Pure Reason (translated by J.M.D Meiklejohn) (2011) 28. 85 Hume D Enquiry Concerning Human Understanding (1748) cited in Dicker (note 75) above 61; see also Macnabb

(note 81) above 49 where Hume is quoted from Hume D Treatise of Human Nature (1739-40) Part III, Section II as

saying: ‘All kinds of reasoning consists in nothing but a comparison, and a discovery of those relations, either

constant or inconstant, which two or more objects bear to each other’. 86 Macnabb (note 81) above 49. 87 Dicker (note 75) above 61; Macnabb (note 81) above 49.


with the car somehow, then one would find it improbable that the person never ever saw or touched

such a car.88 Similarly, if it is known, again through sensory experience, that an accused person

who gives a number of false explanations and testimonies is likely to be not only untrustworthy,

but also guilty, then it is likely that one would infer these two conclusions the next time an accused

person gives false evidence.89

Therefore, causality, in this Humean sense, suggests that the inferential methodology involved in

the assessment of relevance is nothing more than a projection of one probabilistic expectations in

respect of the existence or non-existence of a particular fact in issue based on one’s sensory

experience. In this way, the trier of fact’s outlook in the relevancy assessment is based squarely on

what he or she has perceived, through the senses, before. It is only through this way is the trier of

fact able to transcend from the realm of uncertainty or not knowing to probabilistic knowledge in

respect of the existence or non-existence of facts in issue. Thus, if the drawing of an inference

from the evidentiary facts adduced is the tool, then one’s sensory knowledge about how things

causally relate is the principal guideline.

5. CONCLUSION

The standard thesis which this paper seeks to advance is that the legal concept of relevance is both

substantively relational and functional, as a connector of evidentiary facts and facts in issue, as

well as methodological to the extent that it depends on our sensory knowledge about Humean

causal relations to reach probabilistic conclusions about the existence or non-existence of facts in

issue on the basis of inferences drawn from evidentiary facts.

That being so, it is hoped that understanding relevance in this two-pronged manner shall be but

the first step towards a move away from vague, incomplete and rudimentary descriptions that have

persisted in our law for so long. Eventually, it is further hoped, the many epistemological and

theoretical assumptions, owing largely to the rationalist tradition, upon which our law of evidence

rests shall be reconsidered and interrogated with a view of dignifying this most important area of

law with the purity that any other would science deserve.

88 See R v Du Plessis 1944 AD 314 317-8. 89 See R v Mlambo 1957 (4) SA 727 (A).


BIBLIOGRAPHY

1. CASE LAW

1.1 AA Onderlinge Assuransie Assosiasie Bpk v De Beer 1982 (2) SA 603 (A).

1.2 Caswell v Powell Duffryn Associated Collieries Ltd [1939] All ER 722 (HL).

1.3 Delew v Town Council Springs 1945 TPD 128.

1.4 DPP v Boardman [1975] AC 421 (HL).

1.5 DPP v Kilburn 1973 AC 729.

1.6 Holtzhauzen v Roodt 1997 4 SA 766 (W).

1.7 Katz v Katz [2004] 4 All SA 545 (C) 565.

1.8 Mather v S [1998] 3 All SA 92 (O) 95.

1.9 Motor Vehicle Assurance Fund v Dabuzane 1984 (1) SA 700 (A) 706.

1.10 National Education, Health and Allied Workers Union v Tsatsi [2006] 1 All SA

583 (SCA).

1.11 R v C 1949 2 SA 438 (SR).

1.12 R v Dhlamini 1960 1 SA 880 (N).

1.13 R v Katz 1946 AD 71.

1.14 R v Kumalo & Nkosi 1918 AD 500.

1.15 R v Kotcho 1918 EDL 104.

1.16 R v Matthews 1960 (1) SA 752 (A).

1.17 R v Mlambo 1957 (4) SA 727 (A).

1.18 R v Mpanza 1915 AD 348.

1.19 R v Randall [2004] 1 WLR 56.


1.20 R v Trupedo 1920 AD 58.

1.21 S v Gokool 1965 3 SA 461 (N).

1.22 S v Mtsweni 1985 (1) SA 590 (A).

1.23 S v Shabalala 1986 (4) SA 734 (A).

1.24 Skilya Property Investments (Pty) Ltd v Lloyds of London 2002 (3) SA 765 (T).

1.25 Stellenbosch Farmers’ Winery Group Ltd v Martell et Cie 2003 1 SA 11 (SCA).

1.26 United States v Hickey, 596 F.2d 1082, 1089 (1st Circuit. 1979), cert. denied 444

U.S 853, 100 S.Ct 107, 62 L.Ed.2d 70.

1.27 United States v Schiff, 612 F.2d 73, 80 (2nd Circuit. 1979).

1.28 Van den Berg v Coopers & Lybrand Trust (Pty) Ltd 2001 (2) SA 242 (SCA).

2. INTERNET SOURCES

2.1 Grant J ‘Is Pistorius guilty of murder?’ in Criminal Law of South Africa, posted on

12 July 2014 (blog can be accessed at: http://criminallawza.net/2014/07/12/205/)

(last accessed: 19 July 2014).

2.2 Stanford Encyclopedia of Philosophy at: http://plato.stanford.edu/ (last accessed:

19 July 2014).

3. PEER-REVIEWED JOURNAL ARTICLES

3.1 Cohen L.J ‘The Logic of Proof’ (1980) Criminal Law Review 91.

3.2 Edwards H.T ‘The Growing Disjuncture Between Legal Education and the Legal

Profession’ (1992) 91 Michigan Law Review 34.

3.3 Eggleston R ‘The Philosophy of Proof’ (1991) 65 Australian Law Journal 130.

http://criminallawza.net/2014/07/12/205/

http://plato.stanford.edu/


3.4 Finkelstein M.O and Fairley W ‘The Continuing Debate over Mathematics in the

Law of Evidence: A Comment on “Trial by Mathematics”’ (1971) 84 Harvard Law

Review 1801.

3.5 Gest J.M ‘The Trial of Bridlegoose: As Reported by Francois Rabelais’ (1937) 71

United States Law Review 503.

3.6 Gorayska B and Lindsay R ‘The Roots of Relevance’ (1993) 19 Journal of

Pragmatics 301.

3.7 Hoexter C ‘The Future of Judicial Review in South African Administrative Law’

(2000) 117 SALJ 484.

3.8 Hoffman L.H ‘Those Dogs Again’ (1974) 91 SALJ 237.

3.9 Leonard D.P ‘Minimal Probative Value and the Failure of Good Sense’ (1997-

1998) 34 Houston Law Review 89.

3.10 Michael J and Adler M.J ‘The Trial of an Issue of Fact: I’ (1934) 1224.

3.11 Paizes A ‘Advances in the Law of Evidence: Reflections on Reading the Fourth

Edition of LH Hoffman and D Zeffert’s The South African Law of Evidence’

(1989) 106 SALJ 472.

3.12 Paizes A ‘Chasing Shadows: Exploring the Meaning, Function and Incidence of the

Onus of Proof in the South African Law’ (1999) 116 SALJ 531.

3.13 Paizes A ‘Must we have a theory of proof?: Evidence, Criminal Process and

Criminology’ Acta Juridica (2003) 113.

3.14 Raeder M.S ‘Irrelevancy: Its all in the eyes of the beholder’ (1997-1998) 34

Houston Law Review 103.

3.15 Schum D.A ‘'Probability and the Processes of Discovery, Proof and Choice' (1966)

66 Boston University Law Review 825.

3.16 Trautman H.L ‘Logical or Legal Relevance: A Conflict in Theory’ (1951-1952) 5

Vanderbilt Law Review 385.


3.17 Tribe L.H ‘Trial Mathematics: Precision and Ritual in the Trial Process’ (1971) 84

Harvard Law Review 1329.

3.18 Wigmore JH ‘The Problem of Proof’ (1913) 8 Illinois Law Review 77.

4. STATUTES

4.1 Criminal Procedure Act 51 of 1977.

4.2 Criminal Proceedings Evidence Act 25 of 1965.

4.3 United Stated Federal Rules of Evidence of the United States of America.

5. TEXTBOOKS

5.1 Cohen L.J The Probable and the Provable Clarendon Press Oxford (1977).

5.2 Descart R Meditations on First Philosophy (edited by Andrew Bailey and translated

by Ian Johnston) Broadview Press, Toronto (2013).

5.3 Dicker G Hume’s Epistemology and Metaphysics: An Introduction Routledge,

London (1998).

5.4 Eggleston R Evidence, Proof and Probability (1978).

5.5 Graham M.H Handbook of Federal Evidence West Publishing Co. St. Paul

Minnesota (1981).

5.6 Kant I Critique of Pure Reason (translated by J.M.D Meiklejohn) Pacific

Publishing Studio (2011).

5.7 Keane A The Modern Law of Evidence 5th ed Butterworths London (2000).

5.8 Lempert R.O and Saltzburg S.A A Modern Approach to Evidence: Text, Problems,

Transcripts and Cases West Publishing Co. St. Paul Minnesota (1978).


5.9 Macnabb D.G.G David Hume: His Theory of Knowledge and Morality Gregg

Revivals (1966).

5.10 Morgan E.M Basic Problems of Evidence Copyright office, Library of Congress

Washington (1961).

5.11 McEwan J Evidence and the Adversarial Process: The Modern Law 2nd ed Hart

Publishing (1998).

5.12 Maguire J.M Evidence, Common Sense and Common Law Foundation Press

(2009).

5.13 Murphy P A Practical Approach to Evidence 10 ed Blackstone Press (2008).

5.14 Robinson D.S The Principles of Reasoning: An Introduction to Logic and Scientific

Method 2nd ed D. Appleton and Company, New York (1930).

5.15 Sidgwick A Fallacies: A View of Logic from the Practical Side D. Appleton and

Company, New York (1884).

5.16 Schwikkard P.J, Van der Merwe S.E et al Principles of Evidence 3rd ed Juta

Claremont (2008).

5.17 Stephen J.F A Digest of the Law of Evidence 11th ed Macmillan and Co. Toronto

(1930).

5.18 Thayer J.B A Preliminary Treatise on Evidence at the Common Law Little Brown

and Company Boston (1989).

5.19 Twining W Rethinking Evidence: Exploratory Essays Northwestern University

Press Evanston, Illinois (1994).

5.20 Twining W Theories of Evidence: Bentham & Wigmore Weidenfeld & Nicolson

London (1985).

5.21 Wigmore J.H Evidence in Trials at Common Law 3rd ed Little Brown and Company

Boston (1940).


5.22 Wigmore J.H Evidence in Trials at Common Law volume 1A (revised by Peter

Tillers) Little Brown and Company Boston (1983).

5.23 Zeffert D.T and Paizes A Essential Evidence Lexis Nexus (2010).

5.24 Zeffert D.T and Paizes A.P The South African Law of Evidence 2nd ed Lexis Nexus

Durban (2009).

5.25 Zuckerman A.A.S The Principles of Criminal Evidence Clarendon Press Oxford

(1989).

Understanding Relevance in Causal and Epistemological terms

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