Law, Probability and Risk (2009) 8, 323−351
Advance Access publication on May 14, 2009
doi:10.1093/lpr/mgp011
Is the civil ‘higher standard of proof ’ a coherent concept?
E NNIS M C B RIDE†
Department of Philosophy, School of Humanities, University of Nottingham,
Nottingham NG7 2RD, UK
The standard of proof used in criminal cases is that of proof ‘beyond reasonable doubt’, whereas in
civil cases it is that of the ‘balance of probabilities’. It is commonly accepted that these standards
are coherent ones but a problem arises where criminal conduct has to be proved in civil proceedings:
which standard of proof should be used then? The courts have attempted to resolve this problem by
rejecting the use of a third, intermediate standard of proof for such cases, while at the same time
requiring a ‘higher standard’ of proof in them. This article argues that consideration of this enhanced
standard of proof demonstrates a problem with the concept and questions whether it is a coherent
one, with reference to the various interpretations of the ‘higher standard’ commonly proposed to
account for legal decision making. In particular, a critique is presented of two recent decisions of the
House of Lords, purporting to settle the issue definitively.
Keywords: standards of proof; higher standard of proof; increased scrutiny; degree of belief; degree
of probability.
In Section 1, I detail some basic concepts in standard probability theory to act as a reference
point for the discussion of legal probability which follows1 .
Section 2 sets out an historical overview of the formulation and rationale of the higher standard
of proof (HSP) as laid down by the House of Lords in Re H (Minors)—a standard supposed to lie
between the simple ‘balance of probabilities’ standard used in civil cases and the ‘beyond reasonable
doubt’ (BRD) standard used in criminal cases.
In Section 3, I consider Redmayne’s argument that confusion has arisen from a failure to discern
that there are not one but two such standards of proof.
In Section 4, I give examples of various other types of HSP notably that of the ‘anxious scrutiny’
test, showing how it developed as a seemingly separate concept from the HSP of Re H.
In Section 5, I discuss the legal effect of two House of Lords cases decided on 11 June 2008,
which purported to lay to rest misunderstandings about the HSP and show how they merge the
concepts of ‘anxious scrutiny’ and HSP.
Lastly, in Section 6, I consider whether the HSP, as formulated in Re H and as amended by the
recent House of Lords cases, is a coherent standard of proof. I conclude that the current notion of an
HSP is legally inconsistent and philosophically incoherent.
1. Introduction—axioms and theorems
In discussing the HSP in Section 2, I canvass the possibility of representing its tenets in terms of axioms and theorems. The aim of such an axiomatic approach is partly to invoke and invite comparison
† Email:[email protected]
1 Style note: for the sake of consistency with references to lower courts, I generally refer to the UK’s highest judicial
tribunal—the Appellate Committee of the House of Lords—as a court and to the opinions of its members as judgements
c The Author [2009]. Published by Oxford University Press. All rights reserved.
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with the framework of ‘standard’ probability theory and partly to reap the benefits de Finetti (1972,
p. 67) saw in the process, namely to form a starting point for a ‘complete and rigorous construction
and development’ of the theory and to attain greater precision in discussing it.
1.1
Axioms and theorems
The ‘axioms’ of a probability system are statements that its proponent believes are ‘self-evident
and that should be accepted as such by everyone else’ (see Anderson et al., 2005, p. 253). The
four standard probability axioms (based on the so-called ‘Kolmogorov axioms’) are, in ordinary
language, the following:
(A1) Probabilities are numbers between and including 0 and 1.
(A2) The probability of a tautology or, as Anderson et al. (2005, p. 251) put it, ‘a sure event (one
certain to happen)’ is equal to 1.
(A3) The probability that one or other of two mutually exclusive events will happen is equal to the
sum of their separate probabilities.
(A4) The probability that A will happen given that B has happened (the conditional probability of
A given B) is equal to the probability that A and B will both happen divided by the probability
that B will happen.
The ‘theorems’ of any axiomatic system are just those statements derivable from its axioms by
the logical or mathematical rules laid down in the system. Two well-known theorems for present
purposes are the following:
(T1) the principle of negation: the probability of a statement A is equal to one minus the probability
of the negation of that statement and
(T2) Bayes’ theorem, which expresses the probability of A conditional on B in terms of the probability of B conditional on A.2
1.2
Axiom, definition or theorem?
Despite the references one reads to the standard axioms of probability, there is variation as to the
form in which these are presented. Thus, Howson & Urbach (1996) present axioms (A2)–(A4) as
above, but their first axiom is ‘the probability of an event is greater than or equal to zero’ and they
then derive (A1) above as a theorem.3 Gillies, on the other hand, presents (A1) and (A2) as one
axiom. His second axiom then presents (A3) above as ‘the sum of the probabilities of n mutually
exclusive and exhaustive events is equal to 1’. He then shows that this is equivalent to (A3) as
above.4 Both sources note in discussing the axioms that Kolmogorov himself presented (A4) as a
definition rather than an axiom and discuss the merits of such an approach. Indeed, in his book
for student engineers, Johnson (1994, pp. 59, 71) presents (A1)–(A3) as above but has (A4) as a
definition. For our purposes, it suffices to observe that these differing approaches result in logically
equivalent systems of probability just as, e.g. there are many different but compatible systems of
propositional calculus. This not only bears out the remark of Wittgenstein (2003, Section 142) that
2 See Howson & Urbach (1996) for the derivations of these theorems.
3 See op. cit. at p. 25.
4 See Gillies (2004) at p. 59.
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325
‘it is not single axioms that strike me as obvious, it is a system in which consequences and premises
give one another mutual support’ but also mirrors the extent to which the choice of axioms in the
field of legal probability is a normative one, where it is the judges who write the ‘textbooks’.
2. Historical overview of the HSP before Re B and Re Doherty
In two judgements given on 11 June 2008 (In Re B and In Re Doherty), differently constituted panels
of the House of Lords attempted to lay to rest the question of the meaning of the Re H HSP and in
doing so made trenchant criticisms of what they saw as the errors that had crept into forensic reasoning on the subject of the HSP. I will argue in this article that these recent cases do not in fact clarify
the law but leave it in a more confused state. First, however, it is necessary to discuss the history of
the HSP and of the problems the concept gives rise to and in particular to consider some detailed
criticisms Redmayne makes of the concept. What is the HSP? In courts in England and Wales, two
standards of proof are used: in criminal cases (tried by a judge and jury or by magistrates), proof
must be BRD, but in civil cases (usually tried by a judge alone but in prescribed cases by a judge and
jury), proof is ‘on the balance of probabilities’ (OBOP). A problem arises where, in a civil case, an
accusation of criminal conduct must be proved: if a bank clerk is accused of theft from the vault in
a criminal case, he can be convicted of the offence of theft only if it is proved BRD that he stole the
money in question. However, if the bank sued the clerk for stealing the money in a civil court, the
bank would need only to prove its case OBOP in order for the clerk to be found liable for stealing
the money and for the bank to win an order for compensation from him. But what standard of proof
should the civil court adopt in order to properly recognize the seriousness of the accusation? By way
of contrast: if the bank were merely saying their loss of money was due to the clerk’s carelessness—
say, he dropped the key to the safe in the street when he went out to lunch—it would sue him for
negligence and the standard of proof would uncontroversially be OBOP.
The answer of the courts to this question has been to say that they reject the adoption of an intermediate standard of proof—between BRD and OBOP—and instead to insist that the same standard
of proof be applied to all cases in civil courts, but that where allegations of criminal conduct are
made, ‘more cogent’ evidence of such conduct is required. The issue arose directly in Re H & Ors
(minors) (1995), a case concerning the so-called ‘threshold criteria’ in section 31(2) of the Children
Act 1989 (which says that a court may make a care order only if it is satisfied that the child concerned ‘is suffering, or is likely to suffer, significant harm’5 ). One of several children alleged sexual
abuse against her stepfather. The judge found that while there was a ‘real possibility’ her account
was correct, he did not find it proved OBOP. He therefore found that the threshold criteria were not
made out. The Court of Appeal agreed. On appeal to the House of Lords, it was agreed that the
conclusion that a child ‘is likely to suffer significant harm’ could be merely to the standard of a ‘real
possibility’ but the question was, to what standard must a court find the facts needed to form the
basis for such a prediction—that they occurred OBOPs or merely that there is a ‘real possibility’
that they took place? Lord Lloyd formulated the issue as follows (paragraph 26):
In so far as it is either relevant or necessary in proceedings under the Act to prove an
allegation of sexual abuse, is the standard of proof required (i) a standard higher than
5 In practice, and despite the apparent disjunction between ‘is’ and ‘is likely to’, the issue at this stage is what can be
proved to have happened in the past: there is no question of proving the probability of a probability as to what will happen in
the future.
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the ordinary civil standard though falling short of the criminal standard of proof, (ii) the
balance of probabilities, but so that the more serious the allegation the more convincing
is the evidence needed to tip the balance in respect of it or (iii) the simple balance of
probabilities.
On this issue, Lord Nicholls (with whom Lords Goff and Mustill agreed) preferred answer (ii).
Lord Lloyd and Lord Browne-Wilkinson preferred (iii). The latter two were also in the minority on
the main issue, as they considered that in any event, the court did not have to find facts proved OBOP
at all in order to find the threshold criteria satisfied. In two passages in his judgement, Lord Nicholls
provided an overview of the principles involved in formulating an HSP. He first summarized the
position as follows (paragraph 73):
The balance of probability standard means that a court is satisfied an event occurred if
the court considers that, on the evidence, the occurrence of the event was more likely
than not. When assessing the probabilities the court will have in mind as a factor, to
whatever extent is appropriate in the particular case, that the more serious the allegation
the less likely it is that the event occurred and, hence, the stronger should be the evidence
before the court concludes that the allegation is established on the balance of probability. Fraud is usually less likely than negligence. Deliberate physical injury is usually
less likely than accidental physical injury. A stepfather is usually less likely to have repeatedly raped and had non-consensual oral sex with his underage stepdaughter than on
some occasion to have lost his temper and slapped her. Built into the preponderance of
probability standard is a generous degree of flexibility in respect of the seriousness of
the allegation.
Although the result is much the same, this does not mean that where a serious allegation is in issue the standard of proof required is higher. It means only that the inherent
probability or improbability of an event is itself a matter to be taken into account when
weighing the probabilities and deciding whether, on balance, the event occurred. The
more improbable the event, the stronger must be the evidence that it did occur before,
on the balance of probability its occurrence will be established. Ungoed-Thomas J expressed this neatly in In re Dellow’s Will Trusts [1964] 1 WLR 451, 455: ‘The more
serious the allegation the more cogent is the evidence required to overcome the unlikelihood of what is alleged and thus to prove it’.
This approach also provides a means by which the balance of probability standard can
accommodate one’s instinctive feeling that even in civil proceedings a court should be
more sure before finding serious allegations proved than when deciding less serious or
trivial matters.
Lord Nicholls (paragraph 76) went on to explain the reason for not adopting an intermediate
standard of proof:
The law looks for probability, not certainty. Certainty is seldom attainable. But probability is an unsatisfactorily vague criterion because there are degrees of probability.
In establishing principles regarding the standard of proof, therefore, the law seeks to
define the degree of probability appropriate for different types of proceedings. Proof
beyond reasonable doubt, in whatever form of words expressed, is one standard. Proof
IS THE CIVIL HSP A COHERENT CONCEPT?
327
on a preponderance of probability is another, lower standard having the in-built flexibility already mentioned. If the balance of probability standard were departed from, and
a third standard were substituted in some civil cases, it would be necessary to identify
what the standard is and when it applies. Herein lies a difficulty. If the standard were to
be higher than the balance of probability but lower than the criminal standard of proof
beyond reasonable doubt, what would it be? The only alternative which suggests itself
is that the standard should be commensurate with the gravity of the allegation and the
seriousness of the consequences. A formula to this effect has its attraction. But I doubt
whether in practice it would add much to the present test in civil cases, and it would risk
causing confusion and uncertainty. As at present advised I think it is better to stick to
the existing, established law on this subject. I can see no compelling need for a change.
How should the key elements of this approach—one might call them the axioms and theorems of
the HSP—best be summarized? As noted in Section 1, it is worth considering this question in some
detail as it elucidates the thinking that underpins the judicial concept of probability. The first part of
Lord Nicholls’ argument produces the following scheme:
(A1) The OBOP axiom
The OBOP standard of proof means that an event (at issue) occurred if and only if a court is
satisfied on the evidence before it that the event’s occurrence is more likely than not (i.e. that the
probability of its occurrence is greater than 50%).
(A2) The seriousness axiom
The more serious the allegation the less likely it is that the event occurred.
(A3) The standards of proof axiom
There are degrees of probability but the law seeks to define the degree appropriate for finding
facts proven in different types of proceedings by establishing just two standards of proof appropriate
for them, namely (i) proof BRD (the higher standard) for criminal proceedings and (ii) proof on a
preponderance of probability (the lower standard) for civil proceedings.
From (A2) follows:
(T1) The cogent evidence theorem
The stronger (or more cogent) should be the evidence before the court concludes that a serious
allegation is established on the balance of probability (as we shall see, there is an alternative theorem
considered which I set out here for convenience) or:
(T2) The careful scrutiny theorem
The more careful the scrutiny of the evidence required before conclusions are reached on it. From
(T1) or (T2) and (A3) follows:
(T3) The flexibility theorem
Where a serious allegation is in issue in civil proceedings and thus more cogent evidence or
more careful scrutiny are called for, the standard of proof required is not a higher one than OBOP
but instead represents a degree of flexibility within that standard.6
Three matters should be noted here: first, whether (T1) in fact follows from (A2) is a moot point
but Lord Nicholls links the two by ‘hence’ so he clearly thinks it does and second, while he qualifies
(A2) in the examples he gives (‘fraud is usually less likely than negligence’), the qualification is of
no account here, as it simply acknowledges the notorious ‘reference class’ problem: of course, deliberate injury is not ‘less likely’ than accidental injury in the boxing ring and so on. This just shows
6 To paraphrase a well-known advertising slogan, this makes the standard ‘your flexible friend, the increased credit card’.
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that it is always possible to restrict the reference class of a probability statement until the statement
no longer holds true but this does not affect the truth of the statement as a general statement. Third,
note Lord Nicholls’ appeal to the ‘policy’ argument that one has an ‘instinctive feeling’ that one
should be ‘more sure’ before finding serious allegations proved. As will be seen, Baroness Hale did
not share this view in Re B, at least as far as children cases are concerned.
The three questions to be addressed then are (i) does the set of principles above correctly encapsulate a single HSP; (ii) are the individual principles defensible and (iii) do they, taken as a set,
amount to a coherent whole?
3. One higher standard or two?
The first question is whether the approach to the HSP adopted by the court in Re H is the only such
approach or whether case law shows that different interpretations have been followed. Redmayne
(1999) discusses this question in detail and argues that the courts here have in most cases actually
adopted two approaches to the HSP. Redmayne (1999, p. 176) calls these the ‘flexible standard’ and
‘prior probability’ approaches and finds their source in, respectively, Bater v. Bater and Hornal v.
Neuberger Products Ltd. Redmayne distinguishes these approaches on the basis that under the first,
‘the standard of proof varies according to the seriousness of the issues’, while under the second, ‘the
standard remains fixed but the degree of evidence needed to satisfy it varies because more serious
events are said to be less probable’. In the terms of the schema given above, Redmayne argues that
(T3)—the flexibility theorem—is actually an axiom of one schema and that it is not present in the
other.
In the case of Bater, Redmayne (1999, p. 175) quotes in support of his distinction Lord Denning’s dictum that ‘many great judges have said that, in proportion as the crime is enormous, so
ought the proof to be clear’ and his references to there being ‘degrees of probability within’ the
OBOP standard. As far as Hornal is concerned, Redmayne (1999, p. 176) relies not on the judgement of Lord Denning (who sat in both cases) but on the dicta of Morris and Hobson LLJ that,
respectively, ‘the very elements of gravity become a part of the whole range of circumstances which
have to be weighed in the scale when deciding as the balance of probabilities’ and ‘the balance of
probability may be more readily tilted in one case than in another’. He finds support for his view
in the reference by Ungoed-Thomas J, in Re Dellow’s Will Trusts, to ‘more cogent’ evidence being
needed to ‘overcome the likelihood’ of serious allegations being true, a reference made by the judge
following his quotation of part of the judgement of Morris LJ in Hornal.
Redmayne (1999, p. 177) states that subsequently both flexible standard and prior probability
approaches have been approved by the House of Lords, the first in Blyth v. Blyth and the second in
Re H, and he (1999, p. 179) concludes from this that there is confusion over what the HSP actually is
and whether there is a distinction between the ‘flexible standard’ and ‘prior probability’ approaches.
His argument for saying there is such a distinction—in the face of judicial dicta to the effect that
it is purely academic or semantic—is that ‘one approach raises the standard of proof; the other is
an observation about the quantum of evidence required to satisfy the standard of proof’ and the
difference that this makes in practice is exemplified by cases such as Re M (A Minor) and Re W
(Minors). In the first case, Redmayne says that the Court of Appeal disapproved of a lower court’s
use of the ‘flexible standard’ approach, preferring the ‘prior probability’ approach, and in the second
case, the court distinguished between the standard of proof required to show that a father had abused
his child, as opposed to that required to show simply that the child had been abused. Redmayne
IS THE CIVIL HSP A COHERENT CONCEPT?
329
sees this as a significant difference between the two approaches, as on the ‘prior probability’ view,
once it is proved that a child has been abused, the prior probability that the father was responsible is
quite high so easier to prove, whereas on the ‘flexible standard’ view, an allegation of paternal abuse
‘ratchets up the standard of proof’ thus making it harder to prove. Is Redmayne right on this first
issue, whether there are two distinct approaches to the HSP?
The Court of Appeal (before whom counsel cited Redmayne’s article) thought not, in R v. Secretary of State for the Home Department ex p A.N. This was a case in which a Mental Health Review
Tribunal was faced with competing expert opinions as to whether A.N. was suffering from a psychopathic disorder and could thus continue to be compulsorily detained under the Mental Health Act
1983. A.N. contended that the standard of proof in such a serious matter should be akin to that of a
criminal matter but the Court of Appeal did not consider ‘that more is required than that the decision
is based on cogent evidence which is accepted as correct on the balance of probabilities. It is not
necessary, for example, for one body of evidence to have a much higher degree of cogency before it
can be accepted on the balance of probabilities’.
The court considered the differing terminology used by courts considering the HSP issue but took
the view that while there were ‘differences in the language used and the rationalisations given over
time’, ‘the essential point that runs through the authorities is that the civil standard of proof is flexible
in its application and enables proper account to be taken of the seriousness of the allegations to be
proved and of the consequences of proving them’ (paragraph 59). The court held that the HSP test is,
as laid down in Re H, that ‘the civil standard is one single standard, namely proof on the balance of
probabilities (or preponderance of probability). The other standard is the criminal standard of proof
beyond reasonable doubt. There is no intermediate standard, nor is the civil standard to be broken
down into sub-categories designed to produce one or more intermediate standards’ (paragraph 60).
The court distinguished between the single standard of the HSP and the fact that its application was
to be flexible, the rationale behind this finding being that:
the flexibility of the standard lies not in any adjustment to the degree of probability
required for an allegation to be proved (such that a more serious allegation has to be
proved to a higher degree of probability), but in the strength or quality of the evidence
that will in practice be required for an allegation to be proved on the balance of probabilities (paragraph 62).
The court conceded, however, that while the seriousness of an allegation ‘is a function of the
seriousness of its consequences, and vice versa’, there will be cases where proof of an allegation
may have serious consequences even though it cannot be said that the matter alleged is inherently
improbable, but held that this would not affect the standard of proof to be used (paragraph 64).
On the central question, the court here seems to be correct. To recall, Redmayne’s supposed
distinction between the ‘flexible standard’ and ‘cogent evidence’ approaches is that the first raises
the standard of proof, while the second is an observation about the quantum of evidence required to
satisfy the standard of proof. This is on the face of it a valid distinction: if you maintain the standard
of proof at a fixed level, then if the inherent probability of evidence is seen as smaller in serious
cases, you will require more of it to satisfy your fixed standard of proof in those cases. But what
the court in Re A.N. said is that the second is not a different approach from the first, but is rather a
manifestation of it: the single civil standard of proof is ‘flexible’ insofar as—and only insofar as—it
calls for more cogent evidence. The court then is saying that it is not the standard of proof that is
actually ‘flexing’ but rather the cogency of the evidence required to satisfy it.
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This solution is supported by consideration of the cases which Redmayne claims as examples of
the two approaches. As far as Re M (A Minor) is concerned, while it is true that the Court of Appeal
preferred the phrase ‘prior probability’ to ‘flexible standard’ to describe the HSP, it specifically stated
that ‘we emphasise that the difference is one of expression only’ (p. 67). Equally, in Re W (Minors),
where Redmayne sees a difference between the ‘prior probability’ and ‘cogent evidence’ approach
to proving child abuse by a father (as opposed to by an unknown person), the court expressly stated
that it did not need to consider this distinction, as the father was the only candidate for the role of
perpetrator, in which case ‘a finding that sexual abuse has occurred will inevitably lead to a finding
as to the identity of the perpetrator. In those circumstances the standard must be the single, higher
standard’ (p. 425). Furthermore, even if one goes to the case cited in Re W in which the distinction
was relevant, it is noteworthy that the court held that ‘a higher degree of probability is required to
satisfy the court that the father has been guilty of some sexual misconduct with his daughter than
would be needed to justify the conclusion that the child has been the victim of some such behaviour
of whatever nature and whoever may have been its perpetrator’ (Re G at p. 21). In other words, the
court did not approach the task at hand in two stages (first finding that the child had been abused and
then deciding who the abuser was) at all, but rather considered the issue as a single one, namely to
ascertain whether the father had abused the child. There was thus no question of applying differing
standards of proof at differing stages of the inquiry.
Lastly, if one recalls Lord Denning’s dictum in Bater (‘many great judges have said that, in
proportion as the crime is enormous, so ought the proof to be clear’) which Redmayne claims as the
fons et origo of the ‘flexible standard’ approach, is not the notion of ‘clear proof’ just another way
of expressing that of ‘cogent evidence’? As far as the cases go then, the court’s view in Re A.N.
seems convincing and we can look at Re H as being the definitive statement of a single HSP, applied
in both Bater- and Hornal-type cases.
Having said that, however, the fact remains that Redmayne’s approach is correct in that it reminds us that the adoption by courts of a purportedly uniform concept of proof may mask important
distinctions between elements of it. There are in fact other approaches to an HSP which remain of
relevance, not least because the House of Lords in the June 2008 cases introduced two of them—the
‘close scrutiny’ and ‘quasi-criminal’ standards into the attack on Re H. In order to understand how
these standards arise in the context of an HSP, it is necessary to briefly consider them and how they
have been adopted independently of cases such as Re H.
4. Other HSPs
4.1
Quasi-criminal cases
The courts have held that certain proceedings, though civil in nature, involve issues so serious that
they call for a standard of proof no less than the criminal one of BRD. Examples are B v. Chief Constable of the Avon and Somerset Constabulary (2001) (the making of sex offender orders), Gough v.
Chief Constable of the Derbyshire Constabulary (2002) (the making of football banning orders) and
R (on the application of McCann) v. Crown Court at Manchester (2003) (the making of anti-social
behaviour orders). In the McCann case (heard jointly with, and sometimes cited as, Clingham v.
Royal Borough of Kensington and Chelsea [2002]), the prosecution argued that an application in
the magistrates’ court for an anti-social behaviour order was a civil proceeding which attracted the
‘flexible OBOP’ standard, having due regard to the ‘inherent improbability’ test. Lord Hope (with
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331
whom all members of the court agreed) accepted that the proceedings were civil but held that ‘when
allegations are made of criminal or quasi-criminal conduct which, if proved, would have serious
consequences for the person against whom they are made’ (paragraph 82), then ‘account should be
taken of the seriousness of the matters to be proved and the implications of proving them . . . if this is
done the civil standard of proof will for all practical purposes be indistinguishable from the criminal
standard’ (paragraph 83).
The point which calls for attention here is that this line of cases is consistent with the axioms and
theorems of the HSP suggested in Section 3 above only when considered as a situation where the
seriousness of the matters involved is too great to be contained within the flexible level of the OBOP
at all. As there are only two levels of proof, one has to shift to the next higher level of BRD. What
results is thus not really an HSP at all (in the sense of being a heightened level of proof within the
OBOP) but a special case of the straightforward BRD. The assumption that the seriousness factor
justifies adopting an HSP is criticized by some members of the court in the June 2008 cases as will
be discussed in Section 5.
4.2
Miscellaneous standards of proof
We should mention briefly here some alternative formulations of the HSP which Redmayne discusses
such as the ‘clear and convincing evidence’ test in Addington v. Texas and the ‘reliably shown’ or
‘convincingly shown’ tests as used in the context of the European Court of Human Rights. The
court in Re A.N. considered these and concluded that they ‘may all lead to much the same result in
practice’ as the flexible application of the balance of probabilities standard (paragraph 65), so they
will not be discussed in any more detail here.
Note should also be taken of what is a genuinely different approach, namely that adopted—at
least in the USA—of assigning specific probabilities to the HSP. So, e.g. Tillers & Gottfried (2006,
p. 140, n. 17) note the view of a Federal Judge that the higher ‘clear and convincing evidence’
standard of proof equates to 80%. In this vein, Anderson et al. (2005, p. 230) construct a ‘table
of probabilities’ in which they set a ‘cogent’ standard of proof at 80%, while ‘overwhelming’ is
set at 90% and ‘more likely than not’ at 60%. The difficulty with this approach is that courts here
do not in general deal with figures of probability: the most precise formulation to be found is of
the order of that discussed in the Cream Holdings case. In paragraph 116, e.g. it is noted that the
word ‘likely’ ‘is most commonly used to indicate a degree of probability above 0.5 on the scale of
0 to 1’ but the court also noted that this is not always the case and that indeed the word may not
even imply any particular belief in the person using it. At most, one can discern—in the language
of measurement discussed above—a quasi-ordinal scale of probabilities, ranging at the lowest from
‘mere suspicion’, then ‘reasonable suspicion’,7 then ‘real possibility’,8 ‘may well’9 and, moving
above 50% likelihood, ‘more likely than not’.10 I use the phrase ‘quasi-ordinal’ because, as a referee
has observed, the scale as it stands cannot be purely ordinal as it contains a numerical term (50%)
in the middle. In order to remove any anomaly, it may then be that the scale should be characterized
as measuring two things: belief (above the 50% mark) and non-belief (below it) with the centre
7 R v. Gough [1993] AC 646, p. 667, where Lord Goff distinguishes two lower levels of ‘likely’ than ‘real possibility’,
namely ‘mere suspicion’ and ‘reasonable suspicion’.
8 In Re H (Minors) [1996] AC 563.
9 Black v. Sumitomo [2002] 1 WLR 1562.
10 Bailey v. Rolls-Royce (1971) Limited [1984] ICR 688.
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mark being considered as ‘a state of being non-committal’ rather than accorded the benefit of a
numerical measure.11 Nevertheless, there is no evidence that this scale of measurement can be tied
to the interval level of measurement12 that is represented by the percentage scale—indeed, all the
levels of proof noted here have been described in the cases cited as coming within the meaning of
‘likely’! Of course, one of the main reasons for this aversion to the use of mathematical probabilities
is that cases are simply not decided on the basis of ‘naked’ statistical evidence here, though in the
USA, there has been more use made of statistical evidence—see, e.g. the cases discussed by Tillers
(1997, 2005).
4.3
The ‘increased scrutiny’ cases
Redmayne (1999, p. 177, n. 47) notes a further standard, where it is stated ‘in a few cases’ that
‘more careful scrutiny’ is required. He observes that this approach might seem initially appealing,
but might in fact imply that ‘judges need not be too careful when scrutinizing evidence in less
serious cases’. This point seems a valid one as far as the forensic setting is concerned.13 However, as
a referee has pointed out, there is one important sense in which this notion is borne out in a forensic
setting, namely in the difference in approach to trial procedure between the comparatively informal
magistrates’ court with its lay justices and the highly formal crown court with its professional judges.
Indeed, the average conviction rate after a not guilty plea for 2000–2004 at the Crown Court was
about 35.6% (HO 2005, p. 36) but at the magistrates’ court was more than almost double, at 75.67%
(op. cit., p. 28). There may be numerous reasons for this, but it is clear that an increased ‘level of
scrutiny’ given by a judge and jury is both perceived to be and is a factor (see Darbyshire, 1997, for
a discussion).
11 Achinstein (2003, p. 104) considers a similar scheme, except it has belief and disbelief as positive and negative degrees
along the same axis—this begs the question what they are degrees of.
12 Statisticians distinguish between levels of measurement, the three important ones for present purposes being nominal,
ordinal and interval. Each level of measurement is characterized by its formal properties and by the admissible operations
which exist in respect of it. The three levels relevant here are the following: Nominal—the weakest level, it merely uses
numbers or symbols to classify objects. Its only formal property is that of equivalence, in that members of each group must
be equivalent to each other as regards the criteria for placing them in that group. An example would be classification by
occupation. The only operation admissible here is that of ‘one to one transformation’—say each occupation were ordered
alphabetically and assigned a number in that order, then reversing the order of numbers would not affect the classification of
the objects in question. Ordinal—this scale possesses the formal property ‘greater than’, in addition to that of equivalence.
Thus, if we took the nominal scale of occupations and ranked them by the esteem in which they are held, we would have an
ordinal scale. The admissible operation at this level is that of ‘monotonic transformation’: the numbers used to classify the
groups can be changed, as long as they remain in the same order in relation to each other. Note that even if the underlying
scale is thought of as continuous, since we cannot be sure of the distance between any two points on the scale, we cannot
perform arithmetical operations on it—thus, just because lawyers might be rated 10 on the scale, waitresses 5 and doctors
1, it does not follow that we can say that waitresses are twice as esteemed as lawyers. Interval—on this scale, however, the
distance between each group is known exactly, as with, e.g. temperature. In addition to the properties of equivalence and
greater than, this scale has the property that the differences between the positions on the scale are ‘isomorphic to the structure
of arithmetic’. This means that the admissible operations upon this scale are those of arithmetic (addition, multiplication
and so on) so that one can talk of one measurement being twice as large as another or being the same distance from a fixed
point as another measurement. For present purposes, it is of note that the standard probability scale achieves interval-level
measurement (in fact, it achieves a higher level, namely that of ratio measurement, because it has a true zero but the difference
is not material here). See Siegel (1956, pages 21 ff) for a discussion.
13 Though anyone who has been subject to an Inland Revenue inspection of their accounts, or a personal search at an
airport, will know the difference between ‘scrutiny’ and ‘careful scrutiny’, involving as it can the loss of one’s shirt, either
metaphorically (in the case of a tax inspection) or literally (in the case of an airport search).
IS THE CIVIL HSP A COHERENT CONCEPT?
333
4.4 The ‘anxious scrutiny’ cases
Beyond this sense of ‘careful scrutiny’, the standard of proof arrived at through what is described by
the term of art ‘anxious scrutiny’ is applied in a more substantial number of cases, in England (e.g. Re
Officer L), Northern Ireland (Re Surgula), Scotland (Re Secretary of State for the Home Department)
and Eire (Sweetnam v. An Bord Pleanala). While this standard is most typically applied in asylum
cases where the lives of the asylum seekers in question are at risk, it has been applied generally to
cases where fundamental human rights are in issue even in, e.g. planning cases (see Sweetnam v. An
Bord Pleanala). The common issue running through these cases is whether a court on judicial review
should go beyond its usual role of reviewing procedural propriety on the Wednesbury principle and
actually review a decision on its merits. The answer has been that it should not, but (echoing the
Re H test) that the ‘anxious scrutiny test’ requires that ‘The more substantial the interference with
human rights, the more the court will require by way of justification before it is satisfied that [a]
decision is reasonable’ (per Bingham MR in ex parte Smith). Indeed, in a further echo of the Re H
test, the Court of Appeal in ex parte Mahmood (paragraph 19) referred to a ‘sliding scale’ of the
intensity of judicial review in ‘anxious scrutiny’ cases.
Furthermore, in R v. DPP ex parte da Silva (judicial review of the decision not to prosecute any
police officers as a result of the killing of Jean Charles de Menezes), the Court of Appeal found
(paragraph 49) that there was ‘no material distinction’ between the ‘careful’ and ‘anxious’ scrutiny
tests and decided that on either test, a court should not apply any standard more rigorous than that
of the Wednesbury test.
So what is the practical effect of the test? An example is given by the Court of Appeal in ex
parte AK (Afghanistan), where an assessor had refused to take into account evidence adduced by
an asylum seeker contained in an affidavit from a family member on the grounds that it could not
add probative or corroborative weight to the asylum claim. The court held (paragraph 28) that this
was a misdirection, as there was ‘no trace here of the writer pausing to consider what an independent tribunal might (not would) make of the affidavit and giving anxious scrutiny to that question’.
Similarly, in WM (DRC), the Court of Appeal held that while an asylum decision ‘is only capable
of being impugned on Wednesbury grounds’, it ‘will be irrational if it is not taken on the basis of
anxious scrutiny’, a test which applied ‘in respect of the evaluation of the facts and in respect of the
legal conclusions to be drawn from those facts’ (paragraphs 9–11). The issue here was whether new
evidence submitted following the rejection of an asylum claim could constitute a ‘fresh claim’ in that
it ‘created a realistic prospect of success’ if it were to be referred to an adjudicator for a re-hearing.
The court found that the decision maker should ask not whether he himself considered the new evidence credible, but whether an adjudicator could do so on a re-hearing and give anxious scrutiny to
that question (paragraphs 24 and 26). So while courts tend to identify two issues (the ‘would versus
should’ question and the level of scrutiny needed to answer it), the ‘anxious scrutiny’ test in fact
appears to lower the standard of proof to be applied in that it requires a decision maker not to reject
evidence simply because they do not find it convincing, but to ask rather whether a tribunal might
find it convincing.
A similar result was arrived at in R v. Lord Saville ex parte A, where the court quashed the decision of the Saville Inquiry into Bloody Sunday to withhold anonymity from soldiers giving evidence.
The court observed that ‘Anxious scrutiny is not judicial rhetoric, but an established doctrine with a
discernable shape and direction’ (paragraph 77). In this case, the court held that the Inquiry had used
the wrong test by asking whether there was concrete evidence of specific threats to soldiers giving
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E. McBRIDE
evidence, where they should have asked whether the soldiers had a reasonable fear of such reprisals
(see paragraphs 31, 81 and 106).
Lastly, it is noteworthy that the asylum and immigration adjudicators themselves submitted to a
Parliamentary Inquiry that ‘. . . whilst case law requires adjudicators to give “anxious scrutiny” to
the cases before them, it is often difficult to do so within an adversarial system. . . . the adjudicator
cannot give anxious scrutiny . . . without taking a more active approach to the issues’ and they argued
for the adoption of a more ‘interventionist procedure’ in asylum and immigration appeals (Select
Committee on Constitutional Affairs Second Report, 2004, paragraph 27).
What all these cases seem to indicate is firstly that the argument about ‘anxious scrutiny’ revolves as much around policy issues of reasonableness and proportionality as around issues of levels
of proof. Second, despite talk of ‘sliding scales’ and increased requirements of proof, the real issue seems to turn not on the level of proof needed to establish facts, but on what facts should be
established before findings adverse to litigants are made. Thus, it is not that some sort of special
test is needed before deciding whether, say, there would be a threat to a soldier’s life if he gave
evidence to the Saville Inquiry, but rather that what has to be established, using the ordinary test,
is whether there could be such a threat. Similarly, it is not that a family member giving evidence
in support of an asylum seeker is subject to any type of extraordinary ordeal before their evidence
can be accepted (such as the ducking stool or rack of medieval times), but rather that the evidence
is to be evaluated on the basis of whether it could be true. As a referee has pointed out, since our
law insists that there is no room for finding that a fact ‘might have happened’ (see Lord Hoffman’s
speech in Re B discussed below), this cannot be a statement about the level of proof of facts required
by the concept of ‘increased scrutiny’.14 It seems clear then that, historically, the ‘anxious scrutiny’
standard and the Re H HSP represented different concepts with their own development. However,
as will be seen in Section 5, the two concepts have now become confused following Re B, in which
both were expressed by different judges to underly the HSP.
4.5
Practical objections to the HSP
Before considering any conceptual difficulties inherent in the notion of an HSP, I consider here some
objections which Redmayne raises (for the sake of consistency, I ignore here his perceived distinction
of the Re H approach into two contrary tests—the flexible standard and prior probability—as I have
argued above against the existence of such a distinction). The chief objections are as follows: (a)
having a flexible standard of proof is too vague, as there are no rules for assigning particular levels
of proof to individual cases15 ; (b) there is no empirical support for the prior probability approach,
as we do not know enough about the prevalence of fraud, arson, child abuse and so on to claim
that serious wrongs are less common than less serious wrongs16 ; (c) this approach also ignores the
possibility that allegations of serious but rare events may be more likely to be made when untrue
(e.g. claims of child abuse) or on the other hand, since they are unlikely to happen, it is unlikely
14 The relationship between levels of scrutiny and policy considerations is made explicit in the concept of variable scrutiny
adopted by the U.S. Supreme Court. Thus, strict scrutiny ‘shifts the burden of proof to the government, requires the government to pursue a “compelling state interest” and demands that the regulation promoting the compelling interest be “narrowly
tailored”’, intermediate scrutiny requires the government to establish ‘that its actual purpose substantially promotes an important government interest’ and ordinary scrutiny ‘upholds all action that is a rational means to accomplish a legitimate
government purpose’ (Siegel, 2006, pp. 6–8).
15 See Redmayne (1999) at p. 181.
16 Op. cit. at p. 184.
IS THE CIVIL HSP A COHERENT CONCEPT?
335
that someone will falsely say they did17 ; (d) on the other hand, if all this approach implies is that
‘the inherent improbability of an event is itself a matter to be taken into account when deciding if it
happened’, it is a ‘statement of the obvious’ and it would give cause for concern if judges needed to
be reminded that ‘improbable occurrences are less likely to occur than probable ones’.18
As far as (a) is concerned, the lack of rules for assigning standards of proof to cases is no more
a problem than it is in any policy-based area of law (thus, there is no mechanical ‘rule’ for deciding
whether a defendant was under a duty of care to a plaintiff or whether exemplary damages are
available to a plaintiff, consideration of the latter issue causing the court to comment in Cassell v.
Broome that ‘the life of the law often lies not in logic but in experience’ (paragraph 40)). (b) and (c)
are points I come back to in Section 6. (d) is a point that the court made in Re B, to which I now
turn.
5. The House of Lords attack on Re H
5.1
Re B
The judgements in Re B and Re Doherty were given on the same day by differently constituted panels
of the House of Lords. The first case was an express attempt by the guardian ad litem of children
to have the decision in Re H overturned. As in Re H, the judge below found only that there was a
possibility of abuse of children by their father having occurred, but that it was not ‘more probable
than not’ that he had abused them. The judge therefore proposed, in considering the likelihood of
future harm, to deem the allegations against the father unproven. The House of Lords, in dismissing
an appeal by the guardian, unanimously held that this was the correct approach.
In the course of doing so, the court also revisited Re H and the other cases discussed above in an
attempt to give a definitive ruling on the ‘cogent evidence’ question. Indeed, this aim was expressed
in no uncertain terms: Lord Hoffman held that ‘the time has come to say, once and for all, that there
is only one civil standard of proof and that is proof that the fact in issue more probably occurred than
not’ (paragraph 13) and Baroness Hale, of the notion that ‘the more serious the allegation, the more
cogent the evidence needed to prove it’, stated that ‘It is time for us to loosen its grip and give it its
quietus’ (paragraph 64). Furthermore, this seems to have been the reason the House agreed to hear
the case at all because Baroness Hale accepted (paragraph 23) that the issue had been ‘authoritatively
determined’ by Re H—it was thus nowhere near fulfilling the House’s criteria for departing from its
own decisions (see Practice Statement (Judicial Precedent) [1966] 1 WLR 1234).
Lord Hoffmann’s speech (with which Lords Rodger and Walker agreed) was confined solely to
discussion of this issue, without stating the facts of the case. He made three interesting points: first,
he expressed the nature of forensic proof in explicitly mathematical language:
If a legal rule requires a fact to be proved (a ‘fact in issue’), a judge or jury must decide
whether or not it happened. There is no room for a finding that it might have happened.
The law operates a binary system in which the only values are 0 and 1. The fact either
happened or it did not. If the tribunal is left in doubt, the doubt is resolved by a rule that
one party or the other carries the burden of proof. If the party who bears the burden of
proof fails to discharge it, a value of 0 is returned and the fact is treated as not having
17 Op. cit. at p. 186.
18 Op. cit. at p. 185.
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E. McBRIDE
happened. If he does discharge it, a value of 1 is returned and the fact is treated as having
happened (paragraph 2).
Second, he distinguished three groups of cases: (i) those in which the court has classified proceedings as civil but nevertheless thought that, because of their serious consequences, the ‘quasicriminal standard of proof’ should be applied (e.g. Khawaja), (ii) cases in which it has been
observed that ‘cogent evidence’ is needed to prove ‘inherently improbable’ events (e.g. Hornal,
Re H) and (iii) ‘cases in which judges are simply confused about whether they are talking about
the standard of proof or about the role of inherent probabilities in deciding whether the burden of
proving a fact to a given standard has been discharged’ (paragraph 5).
Third, Lord Hoffman (paragraph 14) emphasized the italicized words in Lord Nicholls’ dictum
at paragraph 73 of Re H:
the court will have in mind as a factor, to whatever extent is appropriate in the particular
case, that the more serious the allegation the less likely it is that the event occurred and,
hence, the stronger should be the evidence before the court concludes that the allegation
is established on the balance of probability.
He said this phrase showed that Lord Nicholls was ‘not laying down any rule of law’ and that
‘common sense, not law, requires that in deciding this question, regard should be had, to whatever
extent appropriate, to inherent probabilities’. Thus, if a child alleges sexual abuse by a parent, he held
that ‘it is common sense to start with the assumption that most parents do not abuse their children’
but that this assumption could be ‘swiftly dispelled by other compelling evidence’. So if, e.g. it was
‘clear’ that a child was assaulted by one or other of two people, a court could not conclude that
neither did so because assault is inherently unlikely, but would have to decide which of the two was
the perpetrator.
Baroness Hale (with whom all members of the court agreed), accepted (paragraph 69) that some
proceedings, though civil in form, required the criminal standard of proof and cited Bater v. Bater,
McCann and Khawaja as examples. However, she held that care proceedings did not require this
standard of proof, as their purpose is not to punish or to deter anyone but solely to protect children from harm. Indeed, she went further and said she wished to ‘announce loud and clear that the
standard of proof in finding the facts necessary to establish the threshold under section 31(2) or the
welfare considerations in section 1 of the 1989 Act is the simple balance of probabilities, neither
more nor less’ (paragraph 70).
She considered also that neither the seriousness of the allegation nor the seriousness of the consequences should make any difference to the standard of proof to be applied in determining the facts
and that the inherent probabilities are ‘simply something to be taken into account, where relevant, in
deciding where the truth lies’. Indeed, she considered that there is no logical or necessary connection
between seriousness and probability, noting that while some crimes such as murder are ‘sufficiently
rare to be inherently improbable in most circumstances’, other seriously harmful behaviour, such
as alcohol or drug abuse, is ‘regrettably all too common and not at all improbable’. Regarding the
Regent’s Park example, she considers that an animal seen outside the zoo on a stretch of greensward
regularly used for walking dogs is ‘of course . . . more likely to be a dog than a lion’, whereas if it is
seen in the zoo next to the lions’ enclosure when the door is open, then ‘it may well be more likely
to be a lion than a dog’.
IS THE CIVIL HSP A COHERENT CONCEPT?
337
In the context of care proceedings, she considered that this applied particularly to the identification of the perpetrator of alleged abuse. Thus, it may be unlikely that anyone caring for a baby would
seriously injure it, but ‘once the evidence is clear that that is indeed what has happened to the child, it
ceases to be improbable. Someone looking after the child at the relevant time must have done it. The
inherent improbability of the event has no relevance to deciding who that was. The simple balance
of probabilities test should be applied’.
Having said that, however, Baroness Hale agreed that the seriousness of the allegation in the
present case required more than the ‘real possibility’ standard in order ‘to protect both the children
and their parents from unjustified intervention in their lives. It would provide no protection at all if
it could be established on the basis of unsubstantiated suspicions’ (paragraph 54). This raises two
points: (1) if Baroness Hale accepts seriousness as determinative of standard of proof on policy
grounds here, at the bottom of the OBOP scale, why does she not also accept that has the same effect
at the top and (2) it is of note that the ‘real possibility’ test is the obverse of the BRD: to find BRD
that D did X is to find that there is no real possibility that he is innocent. So to decide that D did
X only on the basis of a real possibility is to reverse the burden of proof and to require D to prove
BRD that he did not do X .19
5.2
Re Doherty
In the second case— Re Doherty—a differently constituted panel dealt with the case of a life prisoner
recalled to prison following allegations that he had committed sex crimes while on licence and
considered to what standard those allegations had to be proved in order for the prisoner to be properly
denied release on licence under the Life Sentences (Northern Ireland) Order 2001.
Lord Carswell, with whom all members of the court agreed, identified confusion that had arisen
since the judgements in Bater v. Bater and Hornal and confirmed that he saw this being laid to rest
by the statements cited above by Lord Nicholls of Birkenhead in In re H and in In Re B itself (so
we note that the court had the opportunity of reading the judgements in Re B) and by Lord Hoffman
in the notable ‘Regents Park’ passage from Secretary of State for the Home Department v. Rehman
[2003] 1 AC 153, 193 at [55]:
I turn next to the Commission’s views on the standard of proof. By way of preliminary I
feel bound to say that I think that a ‘high civil balance of probabilities’ is an unfortunate
mixed metaphor. The civil standard of proof always means more likely than not. The
only higher degree of probability required by the law is the criminal standard. But, as
Lord Nicholls of Birkenhead explained in In Re H (Minors) (Sexual Abuse: Standard of
Proof) [1996] AC 563, 586, some things are inherently more likely than others. It would
need more cogent evidence to satisfy one that the creature seen walking in Regent’s
Park was more likely than not to have been a lioness than to be satisfied to the same
standard of probability that it was an Alsatian. On this basis, cogent evidence is generally required to satisfy a civil tribunal that a person has been fraudulent or behaved in
some other reprehensible manner. But the question is always whether the tribunal thinks
it more probable than not.
Lord Carswell considered (paragraph 27) the law to be effectively summarized by the passage
from paragraph 62 of ex parte A.N. (cited above) which ascribes the flexibility of the HSP to the
19 See Laudan (2007, p. 300).
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E. McBRIDE
strength of the evidence—rather than the standard of proof—required to find matters proved in appropriate cases.
However, while accepting that the seriousness of an allegation (or the consequences flowing
from it) called for a difference in approach by the court, Lord Carswell said (paragraph 28) that
‘They do not require a different standard of proof or a specially cogent standard of evidence, merely
appropriately careful consideration by the tribunal before it is satisfied of the matter which has to be
established’.
The difference for Lord Carswell is thus that a court or tribunal has to look at the facts ‘more
critically or more anxiously’ in ‘serious allegation’ cases and the reason he gives for this is that ‘if
it is alleged that a bank manager has committed a minor peculation, that could entail very serious
consequences for his career, so making it the less likely that he would risk doing such a thing’—an
approach he saw as being dictated by simple common sense.20
Lord Brown (with whom just one other member of the committee agreed), while agreeing with
Lord Carswell, added that he was troubled by what he saw as ‘an issue of principle at stake here’
(paragraph 39). He identified (paragraph 40) what he considered ‘is unquestionably the most useful
and accurate statement of the position’ as being that made by Lord Hoffmann in the Regents Park
passage from Rehman and endorsed as examples of this approach, those given by Lord Nicholls of
Birkenhead in Re H as being inherently more likely than others (fraud versus negligence, deliberate
versus accidental physical injury and so on).
He agreed too (paragraph 42) that ‘someone with a good character is less likely to behave badly
than someone with a bad character. Someone who values their ‘reputation’ will be less likely to imperil it than someone known to be disreputable’, matters which he saw as ‘obvious’. On the question
of evidence he considered it equally obvious (paragraph 43) that ‘the more inherently unlikely it is
that something has happened, that an allegation is true, the more persuasive (cogent is the word often
used) the tribunal will need to find the evidence pointing that way before concluding it to be more
likely than not’, a view he said he shared with Lord Carswell.
However, the difficulty Lord Brown found was with the idea of requiring stronger than usual
evidence to prove the case OBOP, ‘not to overcome any inherent improbabilities in the case, but
rather because to find it established would have serious consequences for the person against whom
the allegation is made’. He considers (paragraph 46) that if a tribunal has found—merely on the
OBOP—that, e.g. a bank manager has committed fraud, ‘it would be quite wrong for that tribunal
20 As regards the application of the standard of proof, the court in Re A.N. approved (paragraph 77) the test laid down
in the court below which consisted of a series of guidelines such as: if the Tribunal is relying upon hearsay evidence, it
must take into account the fact that it is hearsay and must have regard to the particular dangers involved in relying upon
second-, third- or fourth-hand hearsay. The Tribunal must be appropriately cautious of relying upon assertions as to past
events which are not securely recorded in contemporaneous notes, particularly if the only evidence is hearsay. The Tribunal
must be alert to the well-known problem that constant repetition in ‘official’ reports or statements may, in the ‘official’ mind,
turn into established fact something which rigorous forensic investigation shows is in truth nothing more than ‘institutional
folk-lore’ with no secure foundation in either recorded or provable fact. The Tribunal must guard against too quickly jumping
to conclusions adverse to the patient in relation to past events where the only direct evidence is that of the patient himself,
particularly where there is no clear account in contemporaneous notes of what is alleged to have happened (R v. Mental Health
Review Tribunal [2005] at paragraph 129). Here, Redmayne’s riposte to the notion of differing degrees of ‘scrutiny’ strikes
home: consider, after all, the negation of these guidelines. Are we to suppose that in ordinary civil cases, the court should,
when relying on hearsay, not take into account the fact that it is hearsay? Or not guard against jumping to conclusions too
quickly? So what approach to evidence are judges supposed to take in cases where the HSP is applicable, which they would
not adopt in an ordinary civil case?
IS THE CIVIL HSP A COHERENT CONCEPT?
339
to decide the question in A’s favour merely to save him from the serious consequences of a finding
against him’.
On the one hand, then, he considers (paragraph 48) that certain ‘quasi-criminal’ civil cases—
the McCann type case—do call for a heightened standard of proof (namely the BRD standard). On
the other hand, in the present case, he justifies use of the OBOP standard because, although the
consequences for the prisoner if the allegations of sex crimes were made out (‘long further years
of incarceration in prison’) were indeed serious so too would be the consequences for the public
of his being in fact guilty of sex crimes yet nevertheless released, namely that he would present an
unacceptable risk to them. He justifies the disparity in treatment between those defendants in the
‘quasi-criminal’ cases and the present prisoner on the grounds that as the latter was subject to a
mandatory life sentence, he ‘could not complain’ if ‘the burden of establishing that he could safely
be re-released rested on him’.
It should be remarked here that Lord Brown’s distinction between those ‘quasi-criminal’ cases
requiring the criminal standard of proof (on the ‘seriousness of allegation’ ground) and the present
case seems doubtful—as the trade-off presented between risk to the public and risk to the prisoner
of a wrong judgement exists equally in those other cases. His solution is simply to shift the burden of proof from prosecution to defence in the present case, but if this case involves allegations
deemed sufficiently serious in other cases to warrant a criminal standard of proof, then surely shifting the burden of proof is a proportionately more serious matter. Indeed, it appears inconsistent with
the presumption of innocence now contained in Article 6 of the European Convention on Human
Rights.
5.3
Are Re B and Re Doherty consistent?
Be that as it may, the key question is: do these two contemporaneous cases involving 9 out of 12
members of the highest court in the UK (Lord Scott sat on both cases but did not deliver a substantial
judgement in either) succeed in the aim expressed in the substantive judgements of delivering a
definitive ruling on the HSP question?
As far as Re Doherty is concerned, there is an obvious difficulty: while saying that he agreed
with Lord Carswell, Lord Brown in fact differed in two ways from him. Lord Carswell considered
that (1) the seriousness of the allegation is a factor requiring the HSP but that (2) the HSP is not
related to the cogency of the evidence required but to the care with which it is scrutinized by the
court. Contrarily, Lord Brown considered that (1) the seriousness of the allegation is not a factor
requiring the HSP, though its inherent probability is, but that (2) the HSP is related to the cogency of
the evidence required, in that ‘the more inherently unlikely it is that something has happened . . . the
more persuasive (cogent is the word often used) the tribunal will need to find the evidence pointing
that way’ before finding the allegation proved. In the result, as Lord Brown was in the minority on
this point, his view (and that of Lord Neuberger, who agreed with him) arguably do not represent
the ratio of this case, for which we must look to Lord Carswell’s judgement. The difficulty here is
that while purporting to agree with Re H, the majority judgements in this case agree with it only
as to the HSP being the balance of probabilities, rather than the BRD standard. But they actually
adopt a different approach to what the HSP requires, namely the ‘anxious scrutiny’ test as opposed
to the ‘cogent evidence’ test. There is of course the additional difficulty that as this was not a care
case, the judgements are obiter as far as the reasoning in Re H is concerned—though a House of
Lords decision is always persuasive, even if strictly ‘obiter’, it is always open to a court to take what
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E. McBRIDE
may nowadays seem an overly technical view and disregard such a decision. The view of Lord Reid
expressed in 1962 that the House may depart from one of its own previous decisions where its ratio
‘is much wider than was necessary for the decision’ was indeed resurrected by the Court of Appeal
in 2008 in Actavis UK Ltd v. Merck & Co (at paragraph 82).
Do the judgements in In Re B (Children) then provide a clearer view, given that it was a care
case? Unfortunately, not, for the only question identified by Baroness Hale as at issue was whether
the standard of proof in care proceedings is the OBOP or the BRD one. She saw Re H as holding
that the OBOP was the correct standard and identified the difficulty caused by the case to be that
some courts had taken Lord Nicholl’s reference to ‘more cogent evidence’ as requiring an HSP (held
in McCann (paragraph 37) to be ‘virtually indistiguishable’ from the BRD) in care cases as well as
in the McCann-type cases. On this point, the only one at issue in this case, the court thus merely
confirmed its own clear precedent, as contained in Re H.
What then of the other remarks made by Baroness Hale? These are
(1) that ‘the HSP requires neither “increased scrutiny” nor “greater cogency” but is actually identical for all practical purposes to the BRD standard’ and
(2) that ‘there is no logical or necessary connection between seriousness and probability’, so the
‘cogency test’ should be set aside.
Her first point deals with the McCann-type cases but does not advance the debate between the ‘cogent
evidence’ versus ‘careful scrutiny cases’ approach to the HSP partly because on that issue it is obiter,
even as far as care cases are concerned, but also because it seems to overlook the existence of such
a debate.
Baroness Hale’s second point is of interest as it deals with a central issue, namely the coherence
of the ‘inherent improbability’ notion but again does not advance the debate because of the terms in
which it is framed. First, it is noticeable that both she and Lord Hoffman use as examples cases where
it is ‘clear’ that someone has assaulted a child, then proceed to show that in those circumstances it
would be absurd to say that the ‘inherent improbability’ concept demands that the court ignores the
finding of assault. But it hardly needs stating that of course, if it is clear that the improbable event
has happened, then the court cannot ignore it—but the question the HSP poses is on what evidence
can the court be ‘clear’ on this in the first place?
Second, it must be emphasized that the Re H approach to the HSP never claimed that it was
logically true that serious crimes are less probable than more trivial ones. Although we have (A2)
as the seriousness axiom, it is an axiom only as applied to our legal system—for it to be logically
true, either it would have to be true in every conceivable situation (or ‘every possible world’ as
some would have it) or ‘serious’ would have to be defined as meaning ‘less likely’, but both of these
are absurd. Plainly, one can conceive of situations—e.g. a concentration camp, the Fall of Berlin—
where murder or rape was more common than assault or indecent assault and clearly the concept of
seriousness is different from that of improbability but all (A2) says is that it is a matter of judicial
notice that serious crimes are less common than minor crimes. This is not logically but empirically
true: to get some idea of the figures, we can note that the government’s crime survey, combining
both police and British Crime Survey (BCS) figures, states that in 2007–2008 the police recorded
17 000 ‘serious assaults’ (including 800 homicides) as against a total of 1 000 000 ‘all assaults’
(Home Office, 2008, pp. 64–65). As far as sex offences are concerned, based on 2006–2007 BCS
data, it appears that less than 1% of all adults reported having experienced a serious sexual assault
IS THE CIVIL HSP A COHERENT CONCEPT?
341
as against 2% reporting less serious sexual assaults and all these offences constitute just under 1%
of all recorded crime in 2007–2008 (Home Office, 2008, p. 67).21
5.4
Where is the HSP now?
So what is the state of affairs following these two cases? The following principles emerge from the
older and most recent cases taken as a whole:
(1) In care cases, the standard of proof required to establish facts (and in particular allegations of
abuse) is that of the OBOP—this we knew already from Re H.
(2) Some cases (McCann, Khawaja, etc.) are civil proceedings but because of the seriousness
of the allegations/consequences involved, an HSP is required which is identical to the BRD
standard.
(3) The seriousness of both the allegation made and its consequences are factors requiring the
HSP, as both go to the inherent improbability of the allegations being true (Re Doherty).
(4) The seriousness of neither the allegation made nor its consequences are factors requiring the
HSP, as neither go to the inherent improbability of the allegations being true (Re B).
(5) It is not the seriousness of the allegation made, but its improbability that requires the HSP
(minority view, Re Doherty).
(6) The HSP requires not the ‘cogent evidence’ test but the ‘anxious scrutiny’ test (Re Doherty).
(7) The HSP requires the ‘cogent evidence’ test (Re H and minority view, Re Doherty).
I would argue that it is apparent from the above discussion that Re B and Re Doherty do not
achieve the aim of clarifying the law on the HSP and ironically could be said to be examples of the
third sort of case Lord Hoffman identifies at paragraph 5 of Re B, namely ‘cases in which judges
are simply confused about whether they are talking about the standard of proof or about the role
of inherent probabilities in deciding whether the burden of proving a fact to a given standard has
been discharged’. What is needed from the lawyer’s point of view, in order to achieve an internally
consistent and jurisprudentially defensible answer to this problem, is for one committee of the House
of Lords to consider jointly a care and a non-care case, in both of which the choice between the three
alternatives considered in Re H (higher standard, flexible OBOP standard or bare OBOP) forms
part of the ratio. Furthermore, if the House is minded to depart from the reasoning in Re H, the
committee might be composed of seven Law Lords. So much for the lawyer’s wish list: what would
the philosopher (or the naturalistically inclined lawyer), looking at this from outside the law, make
of this problem?
21 For the sake of completeness, there might be one way in which (A2) is logically true at least for most crimes: it could
be said that any serious crime necessarily includes a lesser crime. Thus, murder includes assault or administering poison or
arson, etc. (depending on the means of death), rape includes indecent assault, robbery includes theft and so on. The point
finds statutory support in Sections 6(2) and 6(3) of the Criminal Law Act 1967, which provide that on an indictment for
any offence except treason, where a person is found not guilty of the offence specifically charged in the indictment, but the
allegations in the indictment amount to or include (expressly or by implication) an allegation of another offence, the jury may
find him guilty of that other offence.
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E. McBRIDE
6. Philosophical perspectives—Is the HSP coherent?
6.1
The central problem
Bearing in mind now the legal history of the HSP, the perspective offered by Redmayne on the
issues raised and the recent rulings in the House of Lords, can we say that the concept of the HSP is
a coherent one? The key problem is that the law requires the HSP to have a degree of flexibility to
deal with more serious allegations but prevents it from flexibility in the most obvious place, namely
the degree of probability required to prove those allegations—obvious because it is only the latter
that comes with a flexible (ordinal or interval) scale of measurement, whereas the standard of proof
comes in only the nominal scale of OBOP or BRD. The law has to look elsewhere for the source of
flexibility and has identified the cogency of the evidence and the closeness of the scrutiny required
as the only real candidates.
Can we even be sure that these two tests are distinct? It might be argued that in one sense,
they must be, as the cogency of evidence is something objective and is brought to the court by the
parties, whereas the closeness of the scrutiny used to examine that evidence is a subjective quality
of the court itself. On the one hand, there is one way in which they could be identical, namely that
the evidence would need to be more cogent just because the court is scrutinizing it more closely
or more sceptically. On the other hand, one can logically distinguish between the two concepts: a
good example is found in section 13 of the Perjury Act 1911, which states that a person shall not be
convicted of any offence against the Act ‘solely upon the evidence of one witness as to the falsity
of any statement alleged to be false’. There is here an objective requirement placed on the evidence
that it should be corroborated, but there is no corresponding subjective requirement for the court to
scrutinize each piece of evidence especially carefully.
This question of distinctness is, it seems, just another way of framing the ‘seriousness’ question;
is it that policy requires a court to be especially careful when an allegation has particularly serious
consequences for a defendant (a subjective requirement) or is that the seriousness of an allegation
makes it (objectively) less likely that a defendant is guilty of it? Here, I would argue, is where the
heuristics discussed in Section 2 above would be of assistance.
6.2
Measuring cogency
Let us consider the three quantities volume, mass and weight.22 First, we can conceive of evidence
which has considerable volume (in that it literally takes up a great deal of space or time) but zero mass
or weight—so any irrelevant evidence will qualify, as will evidence which is relevant but undisputed.
For example, in a road traffic case, if it is undisputed that the road on which P was injured was
wet, then evidence from 10 witnesses to that effect will not advance the case one way or the other.
Second, one can conceive of evidence which has mass but no weight, e.g. where two witnesses each
appear impeccably reliable and truthful and give evidence which is detailed, internally consistent and
highly relevant but nevertheless flatly contradict each other. Here, the joint weight of their evidence
22 Mass must be distinguished from weight. Mass can be defined loosely as ‘the amount of stuff there is in an object’
(Gribbin, 1998, p. 223) and is a scalar quantity, i.e. it has magnitude but no direction. Weight, on the other hand, is defined in
terms of the force exerted on a body by gravity and is the product mg of its mass and the force of gravity. Weight is a vector
quantity, in that it has both magnitude and direction (ibid, p. 95), so an object of mass M will have the same mass on the
moon as it does on earth, but it will weigh less on the moon because the force of gravity there is lower than that on earth
IS THE CIVIL HSP A COHERENT CONCEPT?
343
is zero.23 These examples show why weight should be seen as a vector: it is mass which is pointed in
a certain direction (in this context, towards the truth of an hypothesis such as ‘D is guilty’ or ‘D did
x at time t’) and represents a force acting on a body—indeed, Schum (2001, p. 200) uses evidential
‘force’ in preference to ‘weight’ (to avoid confusion, I will stick to ‘weight’ throughout, even when
discussing Schum’s work).
Schum (2001, p. 219) shows that a vector-like measure of evidential weight is given by the
logarithm of a likelihood ratio derived from a simple form of Bayes’ theorem, namely
(BT1)
P(H |E ∗ ) = P(H )P(E ∗ |H )/P(E ∗ ).
This simple formula actually throws light on the HSP problem so merits further examination.
P(H |E ∗ ) is just the measure of the probability that the hypothesis H is true given the testimony
E (‘E ∗ ’ is just the event ‘witness A says that E 0 ) and for present purposes, ‘H ’ will be the central
hypothesis to be proved, i.e. something like ‘D assaulted A’ or ‘D raped A’.
From (A3) (our ‘standards of proof axiom’) we are given that in a civil case decided on OBOP,
if P(H |E ∗ ) is greater than 0.5 (i.e. ‘more likely than not’), then ‘H ’ is considered to be true and the
plaintiff wins the case.
From (BT1), we can see that the factors which determine the value of P(H |E ∗ ) are P(H ),
P(E ∗ ) and P(E ∗ |H ).
From (A2) (our ‘seriousness axiom’), we know that P(H ) is smaller for more serious allegations
and thus, from (T1) and (T2) we know that in some cases an HSP is needed to take this into account.
But from (T3) we know that P(H |E ∗ ) must be greater than 0.5 and that the HSP flexibility lies
not in the standard of proof required, but in the cogency/scrutiny of evidence required.
It therefore follows as a matter of simple algebra that in order to solve the resulting equation,
it must (a) be the term P(E ∗ |H )/P(E ∗ ) which increases and (b) that this quantity measures the
cogency/scrutiny factors, where P(E ∗ ) is just the probability of a witness giving the evidence he
does: saying, e.g. that he has been assaulted, and P(E ∗ |H ) is the probability of his giving this
evidence given that he actually has been assaulted. In other words, P(E ∗ ) is a measure of all those
cases where a W says E, including those in which E has actually occurred (so W is being truthful)
and those in which it has not (so W is not being truthful). But this brings us back (see Section 4.5
above) to the practical issues raised by Redmayne about how the precise ‘inherent improbability’
idea squares with the imprecisely known probabilities of (a) someone actually being the victim of a
serious crime and (b) saying he is a victim.
6.3
Policy v. probability
In terms of our equation (BT1), the two difficulties for the concept of an HSP is that while the term
on the left—P(H |E ∗ )—can be and is fixed by policy at 0.5, the terms on the right-hand side (a)
reflect reality and can thus not be changed as a matter of policy and (b) they are not precisely or even
roughly known. Difficulty (a) consists of the brute fact that although policy demands they increase
for serious allegations (i.e. that the cogency of E should increase), the facts may simply not be up to
the job and difficulty (b) consists of the fact that we do not have enough evidence to calculate them
anyway. While we could arrive at a figure for P(E ∗ ) by simply adding together the total reports of
23 Schum (2001) details the probability calculus involved in assessing redundant and contradictory evidence in sections 8.4
and 8.1, respectively.
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crime made to police and dividing by the total population, how could we calculate the true figure
for P(H )? We could (and in the UK, the BCS does) simply use statistical sampling to gauge how
many people had been subject to crime and this figure would no doubt be higher than P(E ∗ )—
i.e. many people do not report crime when it happens to them.24 We could then ask these victims
how many of them had reported the crime to the police and thus calculate P(E ∗ |H ). But how could
we know if their answers to the survey were true, not so much as to whether they reported a crime,
but as to whether it happened to them in the first place because ex hypothesi, those victims will be the
very ones whose stories are not tested in any court? It might be objected to this that as the evidence
in every case is different, the ‘E ∗ ’ on the left-hand side of (BT1) refers to the unique evidence in
each case. But if this were so, then the P(E ∗ ) on the right-hand side could not be calculated by the
survey method mentioned above or by any other practical method so the equation would be useless
and there would be no way of checking if the resulting finding was statistically defensible. For these
reasons, it does not look like going further down the Bayesian road will solve the HSP problem, as
any Bayesian measure of P(H |E ∗ ) is going to consist of different arrangements of the same basic
terms mentioned above.25 It may be then that there is a category error lurking behind what the HSP
demands in that a normative demand (that cogency be increased for serious allegations), an objective
fact or facts (the statistics of crime and the mathematics of the Bayesian equation) and a subjective
notion (that cogency measures changes in belief) are confused in order to meet a wish to effect the
HSP without changing the standard of proof being utilized.
6.4 Subjective/objective v. cogency/inherent probability
I referred above to an apparent conflict between ‘cogency’ (apparently an objective, mathematically computable measure of the effect evidence has on probabilistic support for hypotheses) and
‘scrutiny’ (apparently an imprecise measure of the subjective approach a judge or jury take to
their evaluation of evidence). Could there be an analogous mismatch at the heart of the HSP between ‘cogency’ and ‘inherent improbability’ if we take the former to be a measure of how evidence changes your belief in the probability of D’s guilt or innocence (thus a matter of subjective
probability) and the latter to be a measure of the relative frequency with which certain events
happen (thus a matter of objective probability)? A parallel analogy is the idea mooted above
24 In fact, an estimated 60% of crime is unreported (Smith, 2006, p. 8).
25 For the same reason, it is unlikely that use of non-Bayesian evidence theories would save the HSP. For example, Cohen’s
(1977, p. 132) theory of Baconian support would seem ideally suited to a court setting as it measures the support W ’s
evidence has for H in terms of the number of tests the evidence passes, so you might test support for the hypothesis ‘bees
can see colours’ by conceiving a series of six tests and then seeing if the bees pass each test—support for H then equals n/6,
where n is the number of tests passed. In court, this would equate to counsel testing W ’s evidence by asking a series of say
10 questions, with the jury deciding how many W passes (i.e. answers credibly). At the end of the case, if H (D is guilty)
passes n tests and −H (D is innocent) passes only n − 1 tests, then H is found proved. But the problem is that there is no way
of knowing how many tests there are or of ordering the tests in any unique order and support is thus a non-additive function
(Cohen, 1977, p. 229). So counsel A may ask witness W1 10 questions about issue x, whereas counsel B may ask witness
W2 20 questions—some the same, some different from counsel A’s questions—about the same issue. If W1 scores 5/10 and
W2 scores 12/20, it is not possible to say one witness is more credible than the other or that H derives more support from one
than the other. More fundamentally, the system provides no method for actually testing W ’s answers in the first place—Cohen
(1977, p. 275) suggests that a jury should base its decisions on ‘generalizations’ consisting of ‘proverb, myth and legend’
among other things!! This is either a recipe for reliance on slander and gossip or a disguised appeal to the standard frequency
theory of probability which Cohen claims is completely separate from his support theory: for what is the ’generalization’ that
‘shifty-eyed people are liars’ other than an observation that ‘of the shifty-eyed people I have met, most are liars’?
IS THE CIVIL HSP A COHERENT CONCEPT?
345
that Re H might represent a category error, confusing a normative measure, fixed by policy (the
left-hand side of equation (BT1))—hence subjective—with measures fixed by actual frequencies
of crimes and reports of crimes (the elements of the right-hand side of the equation)—hence
objective.
Broadly speaking, an objectivist account of probability holds that probabilities are external features of events, whether in the sense of being frequencies with which events occur, propensities of
apparatus to cause those events or logical relations between statements about events. A subjectivist
account of probability holds that probabilities are internal degrees of belief, whether actual belief
or hypothetical belief (measured by what you would bet on an event in certain circumstances). On
the face of it, the subjectivist account would seem more fitting for the legal context: first, it would
reflect the fact that much of legal fact finding depends on the evaluation of testimony: what is being
assessed is the credibility of witnesses and one speaks naturally of the degree of belief one has in
what another person testifies to.
Second, a subjectivist account also seems the obvious candidate for the philosophy of the criminal standard of proof, expressed as it is in terms of ‘reasonable doubt’ (the sole officially approved
definition for this phrase, should a jury ask what it means, is that X is proved BRD if the jury are
‘sure’ that X occurred) and it would be clearly undesirable to have differing theories of probability
for the criminal and civil courts. Third, as a court case for the most part deals with unique, past events
(‘did A hit B’, ‘did Dr C inject D with the wrong drug’, etc.), neither the frequency nor propensity
theories would seem to apply to legal probabilities as they both hold the probability of a particular
outcome X to be a function—x/y—of the number of times X occurs or can occur divided by the
total number of all possible outcomes in question. This is arguably26 ruled out because the event X
at issue either did or did not happen, hence P(X ) equals either 0 or 1, as noted by Lord Hoffman in
Re B.
On the subjectivist account, ‘cogency’ appears a more natural concept to understand in that
evidence is more cogent just insofar as it causes us to revise more strongly held beliefs. Recall Lord
Hoffman’s claim in the ‘Regents Park’ passage in Rehman that it ‘would need more cogent evidence
to satisfy one that the creature seen walking in Regent’s Park was more likely than not to have been a
lioness than to be satisfied to the same standard of probability that it was an Alsatian’. If we replace
‘satisfy’ with ‘convince’, then we taste the true flavour of the subjectivist approach. Baroness Hale,
of course, decried this approach in Re B, claiming that it was obvious that ‘an animal seen outside
the zoo on a stretch of greensward regularly used for walking dogs, is of course . . . more likely to be
26 There is opposition to this argument from three directions: from a subjectivist viewpoint, de Finetti (1990, p. 266) rejects
a ‘naı̈ve objectivism’—which considers every event to be true or false—and distinguishes between ‘genuine’ (verifiable)
events which could be true, false or ‘indeterminate’ and ‘bogus’ events which are either not events at all or are ‘intrinsically
indeterminate’. From an objectivist stance, there are those who argue that an objectivist theory can account for past, single
case events (see Redmayne, 2003, for a discussion). From a radically different perspective, those such as Zadeh (2002,
p. 232) argue that while standard probability theory is of value in some fields such as physics, in others such as economics, a
probability theory based on fuzzy logic and fuzzy sets is needed since ‘The denial of partiality of truth and possibility has the
effect of seriously restricting the ability of probability theory to deal with those problems in which truth and possibility are
matters of degree’. The intolerance of courts for such an approach is exemplified by cases such as DPP v. King [2008], where
the Divisional Court considered whether a small scooter with a top speed of 10 mph and powered by a battery powered electric
motor was a ‘motor vehicle’ as defined by section 185 of the Road Traffic Act 1988. The defendant had been driving on a
road but was acquitted by a district judge at first instance because the judge did not find it proved BRD that any reasonable
person looking at the scooter would say that one of its uses would be use on the road. The acquittal was quashed and the case
remitted to the judge with a direction to convict, as the appeal court held that the question was whether the scooter ‘might
well’ be used on a road and there could only be one answer to that question in this case.
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a dog than a lion’, whereas if it is seen in the zoo next to the lions’ enclosure when the door is open,
then ‘it may well be more likely to be a lion than a dog’ but this rather spectacularly misses the point
that Lord Hoffman was making. It is true enough that London Zoo occupies a small, discrete part
of Regent’s Park but it is clear that Lord Hoffman was not thinking of the zoo when discussing this
issue—the zoo is that other sort of animal, a red herring—but of any typical park. What we have here
is the problem of the reference class: of course, if you narrow this class down sufficiently far and start
talking of open cages in a zoo, you change the probabilities involved. Indeed, Baroness Hale cites
a perfect example of this, when she argues that while it is improbable that one would deliberately
injure a baby, ‘. . . once the evidence is clear that that is indeed what has happened to the child,
it ceases to be improbable’ (paragraph 73). This is itself an instance of stating the probabilistically
obvious but misses the point that the HSP must be applied while assessing whether the evidence goes
to show that it is ‘clear’ that deliberate abuse took place. The ‘park’ example is thus a fairly good
and neutral choice of setting where the initial probability (be it subjective expectation or objective
frequency) is low for the presence of lions but not impossibly low nor obviously high, between the
extremes of ‘I saw a lion in a lion’s cage’ and ‘I saw a lion under my bed last night’.
As a matter of fact this very point was demonstrated in a tragic case of life imitating art reported
in the Times on 3 January 2008, where a man locked in a San Francisco zoo after closing time on
Christmas Day was killed by an escaped tiger. The phrases used are telling: his companions ‘tried
to get help for more than 30 minutes before zoo workers finally called police’. They ‘approached
a female security guard, but she appeared “diffident” despite their appeals for help’. Eventually,
someone called the police but the police phone operators noted that ‘Zoo personnel dispatch now
say there are two males who the zoo thinks ... are 800 (police code for mentally disturbed) and
making something up ... but one is in fact bleeding from the back of the head . . . They say they were
acting crazy’. Note that what we have here is a report of a big cat walking inside the zoo, but not
even the zoo workers believed it—why? Just because here (pace Baroness Hale) there was no ‘open
cage’—any more than there is a ‘smoking gun’ in most criminal trials—and what evidence there
was was not cogent enough because it was inherently more likely that the distressed witnesses were
crazy people than victims of an escaped big cat! Indeed, one can imagine that the zoo workers were
faced every year around New Years Day with drunken gatecrashers getting themselves injured in
the zoo and claiming escaped tigers (or pink elephants) had attacked them, whereas they had never
been faced with a big cat escaping—in this sense, their approach was perfectly rational and an ideal
example of the Re H HSP in action.
A number of morals can be drawn from this story. First is that rare events, when experienced
directly, do not as such require more cogent evidence to convince us they happened: if the zoo
worker had seen before her a tiger jump over its enclosure and maul a spectator, she would not
ignore his cries for help on the grounds that, while she would, without further ado, offer assistance
to the victim of a commonplace dog attack, in the case of a purported tiger attack, more proof of the
event would be required. This equation of rareness with improbability is another type of probabilistic
category error: it plays on the idea that just because something is unlikely to happen then it would
not or has not. The probability of drawing at random a king of hearts from a pack (1/52) is 26 times
smaller than that of drawing a black card (1/2), but we would not require more cogent evidence
to satisfy ourselves of its happening. Indeed, as Howson & Urbach (1996, p. 172) note, ‘events of
miniscule probability are ubiquitous’.
On the other hand, when considering indirect evidence of rare events (including testimony about
them), we should not confuse preference for one hypothesis over another, with belief that a particular
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347
hypothesis is true. A zoo worker faced with evidence from two disturbed men that their companion
had been mauled by a tiger might well prefer a more likely hypothesis—that they were mentally
disturbed or drunk. Further evidence (sight of blood or teeth marks on them, say) might lead the
worker to prefer the hypothesis that they had been attacked, but by another person or a dog. It would
then take yet further evidence (say sight of paw prints or dung) to lead her to accept the hypothesis
advanced in preference to her earlier hypotheses. What is happening here is not the mathematical
calculation of the probability of each hypothesis, but a simple weighing of one theory against another to see which is preferred (an analogy might be between a Bayesian lawyer in a shop choosing
between two pineapples by weighing each on his pair of portable scales, and an ordinary customer
in the shop choosing between them by holding one in each hand and seeing which is heavier).
This line of thinking dates from at least the 17th century Port Royal Logic, in which, as Hacking
(2006, p. 78) notes, is an example where a decision maker starts with a quantitative probability (that
a document is 99.9% likely to be genuine) and then uses evidence of the characteristics of the author
to weaken this probability ‘in a qualitative fashion until it simply vanishes’, thereby reaching the
conclusion that there is something false about the document. This notion of probability as a vague
everyday concept finds expression in the present context in the proposal of Allen & Lively (2003, pp.
52–53) that ‘litigation involves the choice by the fact finder over the stories advanced by the parties
(or of a story constructed in light of the parties), and that proof is largely comparative or ordinal
rather than cardinal, as entailed by conventional probabilistic accounts. It is not the conjunction
of elements that determines outcomes; it is whether the plaintiff’s story is more plausible than the
defendant’s’. The lack of definition of this concept is, they claim, a reflection of its everyday use:
we are trying to explain human decision making in litigation, and from that perspective
there is no a priori reason why any particular concept needs to be well defined in a
logical sense. Everyone reading these sentences has full confidence in their general
capacity to make judgments of the relative plausibility of different scenarios; everyone
does it all the time (2003, pp. 59–60).
Such a view was suggested by Morris LJ in Hornal v. Neuberger Products Ltd (1957, p. 266)
when he said:
The phrase ‘balance of probabilities’ is often employed as a convenient phrase to express
the basis upon which civil issues are decided. It may well be that no clear-cut logical
reconciliation can be formulated in regard to the authorities on these topics. But perhaps
they illustrate that ‘the life of the law is not logic but experience’.
The notion of ‘balancing’ one theory against another also sits better with the notion of the
‘weight’ of evidence. It seems to me unfortunate that the use of ‘support’ has become accepted
to describe a situation where evidence increases the acceptance of a hypothesis, so that that evidence
is said to ‘support’ the hypothesis. This is because if ‘weight’ is a force acting downwards, then how
can it also act ‘upwards’ which is what ‘support’ tends to suggest? If on the other hand we choose
the appropriate metaphor of justice’s scales, then evidence in one pan of the scales will, through its
weight, act to raise or lower the other pan, in which lies the hypothesis being tested. If each pan is
then set in front of a scale of probability, the evidence can then be thought of as raising the hypothesis
to the required level.
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The third moral follows from this, and it is that we do in fact—pace Baroness Hale—require
more cogent evidence to prove an improbable event even in a childcare case, in the sense that at
every stage (not just at the first stage of proving there has been an assault) if there are two or more
alternatives (assault versus no assault, parent versus non-parent, mother versus father), we will prefer
the more plausible, even if that plausibility is determined just by what Gilovich & Griffin (2005,
p. 3) term the ‘quick and dirty’ heuristic of choosing whichever alternative is less rare and hence
more immediately similar to our everyday experience. The down side of this, as far as the Re H
notion of the HSP is concerned, is that there is no reason why our resulting probability for the
allegation at issue having occurred should end up as 50%+ (more likely than not) because the ordinallevel measurement of ‘preference’ for A over B need not convert to the interval-level measurement
of ‘degrees of probability’ and even if it does, may be insufficient, given the seriousness of the
allegations, to allow a jury to feel ‘satisfied’ that the allegation happened ‘more likely than not’.
The final moral is that the various terms used in discussion of the HSP, such as ‘cogency’, ‘frequency of events’, ‘careful scrutiny’, ‘balance of probabilities’ and so on, are often thrown together
as if they are philosophically all of a piece when in reality there is no overarching theory which can
accommodate their use. If our courts are to arrive at rationally defensible rulings on evidential issues
and produce a ‘theory of evidence’ that can hold together the disparate elements involved here, then
issuing a reasoned, consistent, comprehensive and binding ruling on the HSP would be as good a
place as any to start.
6.5
Conclusion—wishful thinking?
Tillers (2005, p. 46), in discussing the reluctance of a court to use ‘naked statistical evidence’ in
sentencing a Nigerian drug-smuggler, based on the amount of drugs smuggled by other Nigerians,
quotes from a nursery rhyme: If wishes were horses, beggars would ride. He argues that when a court
bars the use of a particular form of evidence or inference, the public has a right to know whether
this is because judges think that ‘using such evidence causes social mischief . . . or because . . . the
use of that kind of evidence or inference increases the risk or frequency of factual error in legal
proceedings’. It could be argued that the problem of the HSP arises from a similar cause, namely
that judges in certain civil cases have the laudable desire to adopt a more rigorous approach before
finding proved serious allegations that could ruin those against whom they are made. But, rather
than bite the bullet of classing all such cases as quasi-criminal and requiring the BRD standard of
proof, judges try to find a half-way house by using the OBOP while requiring an increase of some
mythical element, be it ‘cogency’ or ‘scrutiny’, which is not related to probability. The difficulty
then is that the flexibility then achieved is either entirely trivial (such as ‘unlikely things are unlikely
to happen’), non-existent (such as the ‘careful as opposed to careless scrutiny’ test) or subject to the
whims of hard reality (which may result in the standard of proof being unattainable or too easy to
attain or simply unmeasurable).
Surely what is needed is first, a forthright recognition of the fact that an increase of any element
of a trial (be it number of witnesses, type of evidence, type of cross-examination required and so on)
is going to affect the probability of errors being made and thus affect the standard of proof used to
reach a finding. One then needs to adopt a logically defensible description of this standard of proof,
commensurate with the resulting change. Since U.K. courts have not yet come up with a convincing
way of distinguishing between different levels of the OBOP, other than in those rare cases where a
mathematical level of probability can be fixed, it is likely that the BRD would have to be adopted in
IS THE CIVIL HSP A COHERENT CONCEPT?
349
place of the HSP and thus all civil cases where criminal allegations were made would be consistently
dealt with as quasi-criminal. Ultimately, though, this would be a question of policy for the House of
Lords to decide.
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