New Zealand Law Students Journal
Last Updated: 14 January 2013
RECONSIDERING THE BUT FOR TEST IN THE CRIMINAL LAW
The first step in any consideration of causation problems in criminal law is
said to be the application of the but for test: would
the consequence defined in
the relevant provision have occurred but for the defendant’s conduct? Its
application appears so
simple that it seems little argument has been made in
criminal law in New Zealand over the way it should be applied. It is true that
in most cases the result would be the same irrespective of the way it is
applied: the identical conclusion would be reached
automatically. However, as
discussed below, there may be cases the conclusion of which differs according to
the way it is applied.
A workable, reliable test is the one which provides an
objective standard according to which the same conclusion is to be reached
relation to the same matter whoever applies it.
There are two issues which may need attention regarding the
application of the but for test:
(1) What conduct is the but for test interested in?
(2) What consequence should the but for test be concerned with?
The first question is not so much one of how the but for test should be
applied as of what conduct the but for test should be applied
to. It is
nevertheless of practical importance and thus will be discussed below. The
second question is involved with how the consequence
in question should be
viewed, in concrete terms or in the abstract.
Besides these issues, there has been argument as to whether there is
∗ LLB, Osaka University; LLM Waseda University. Studying towards GCertLaw, Victoria
University of Wellington. The author would like to acknowledge Rebecca
Thomson for her information and advice and Takayuki Kato for
need to modify the but for test or the way it is applied to accommodate some
unusual, difficult circumstances. The most troublesome
are the cases of
alternative concurrence discussed below.
Lastly, there is a more fundamental problem; that is, is there any need to
adhere to the but for test or the enquiry for a factual
nexus between the
defendant’s conduct and the result in question? The discussion which
follows briefly surveys these problems
in the context of criminal law.
A. The conduct and the consequence to which the but for test is applied
Some crimes (that is, result crimes) require as actus reus not only
conduct but also a particular consequence and causation.
Generally, causation in
criminal law is to be considered from two distinct perspectives: whether there
is a factual cause; and, if
there is, whether there is a legal cause.
The first issue is determined by applying the but for test, the test to
narrow down the object of consideration: it
consideration the conduct which requires no further causal enquiry. Its
application is usually easy, entailing no
policy decision. If the consequence
would not have occurred but for the conduct in question, there is factual
causation between the
conduct and the consequence; if the consequence would have
occurred, there is not.
At this stage two questions may arise: (1) What conduct is the but for test
interested in? and (2) What consequence should the but
for test be concerned
1. What conduct is the but for test interested in?
When causation is comprised in constituent elements of actus reus, what we
need to determine first is whether there is an act (or
omission) which falls
within the relevant actus reus; that is, whether there is an act (or omission)
prohibited by the relevant provision.
The next issue we
will consider is whether the consequence specified in the actus reus did
occur. The problem of causation comes third for the practical
causation is a link connecting the prohibited act (or omission) and the
consequence, and thus these two things have
to be confirmed in advance.
To take an example from Principles of Criminal Law,1 suppose that D invites V for lunch, whose car is hit by a truck on her way to their rendezvous, the brakes of which have failed. In such a case, the criminal law will look first at the driver of the truck or its manufacturers concerned to determine whether the driver’s or manufacturers’ conduct falls within the relevant actus reus. Only after confirming the relevant consequence will causal enquiry be instituted, that is, whether there is factual causation as between the driver’s or manufacturers’ conduct and the consequence. The question of whether there is factual causation between D’s invitation and the consequence does not arise unless some evidence exists suggesting, for example, that D knew such an accident would happen and that the act of invitation constitutes the relevant actus reus. In the absence of such exceptional conditions, on those facts above, there is no prohibited act on the part of D from which causation flows which needs to be considered.2
Occasionally, the but for test is applied not only to the conduct falling
within the actus reus but also to the conduct obviously not falling within
the actus reus and the result of its application has been
This, however, would seem confusing. Since the but for test is the one
to investigate whether the conduct in question constitutes
crime, there is no practical purpose in the application of the but for
test to those acts or omissions which
are not prohibited by the law. Causation
is one constituent element of actus reus. It is a link connecting
conduct and the consequence; accordingly, no problem of
causation will arise, at least for the purpose of assessing criminal
in the absence of some
1 AP Simester and WJ Brookbanks, Principles of Criminal Law (3rd ed, Wellington, Brookers, 2007) 57.
2 See Peter Cane, Responsibility in Law and Morality (Hart Publishing, 2002) 120. See also Jonathan Herring, Criminal Law Text, Cases, and Materials (2nd ed, Oxford University Press, 2006) 102.
3 See, for example, Simester and Brookbanks, above n1, 57,
2. What consequence should the but for test be concerned with?
Another question which arises is how the but for test ought to be applied; in
other words, to what consequence ought the but for test
There are two possible approaches. One approach, taking the consequence in general terms, applies the but for test in the following way: would a consequence defined in the relevant actus reus have occurred (probably in any way) but for the defendant’s conduct?5 The other, on the other hand, taking the consequence in concrete terms, applies the but for test in the following way: would the specific consequence which did occur have still occurred at the same time in the same way but for the defendant’s conduct?6
Again, to borrow an example from Principles of Criminal Law,7
suppose that D sets fire to V’s house, razing it. It turns out that
there was a faulty electrical circuit in the house about
to overheat and cause a
similar fire. According to the first approach, factual causation cannot be
established between D’s
setting the fire and the destruction of V’s
house. This is because V’s house would have been burned down by the faulty
electrical circuit but for D’s conduct.
4 Glanville Williams, Textbook of Criminal Law (2nd ed, London, Stevens, 1987) states that “[s]urely the notion of but-for causation is ridiculously wide” but that when the but-for causal enquiry is made “one starts with the defendant who is charged” (p 379).
5 See, for example, Simester and Brookbanks, above n1, 58; and R Wright, “Causation, Responsibility, Risk, Probability, Naked Statistics and Proof” (1998) 73 Iowa LR 1022. Don Stuart, in his book Canadian Criminal Law (5th ed, Ontario, Carswell, 2007) at p 150, describes this way of application as “mechanical”.
6 For example, Herring, above n2, 102; Richard Card, Sir Rupert Cross and Philip Asterley Jones, Criminal Law (17th ed, Oxford University Press, 2006) 69; Michael Allen, Textbook on Criminal Law (9th ed, Oxford University Press, 2007) 34; and David Ormerod, Smith and HoganCriminal Law (10th ed, London, Butterworths, 2002) 43, who indicates this approach saying “[the but for principle] is that D’s act cannot be the
cause of an event if the event would have occurred in precisely the
same way” but for the act (emphasis mine).
The second approach, on the other hand, would find factual causation at least
if it can be proved that the house would not have been
razed as and when it was
but for D’s act. This approach has commonly been espoused by academics in
Japan,8 whereas in New Zealand the but for test is relied upon as a
first step to solve the problem of causation, though as discussed below
function of the but for test differs between the two.
The latter approach in Japan will generally go as far as to adopt the
principle which does not allow one to give consideration to
what did not
actually happen.9 In the above case where D sets fire to V’s
house, even if the faulty electrical circuit might have caused a similar fire,
might have razed the house in the same way at the same time,10
but for causation, according to that principle, would be established. This
is because that principle does not take into account the
fire which the faulty
electrical circuit would have caused. It is only one hypothesis which did not
actually happen. If one can consider
any hypothesis event in applying the but
for test, its application will become rather arbitrary11 and the
but for test will not function as an objective standard.
The difference between those two approaches seems to derive from their slants
on the function of the but for test. Generally speaking,
the idea underlying the
second approach is that “[s]omething cannot be a legal cause unless it is
a factual cause”.12 In other words, the but for test tells us
whether the conduct was a necessary condition of the consequence in
question.13 It follows that if the conduct is found to
8 For example, Minoru Oya, Keihokogisoron (3rd ed, Tokyo, Seibundo, 2007) 221.
9 This is the principle of disallowance of adding any hypothetical event which did not actually happen, the principle which is commonly accepted in Japan. However, this principle needs qualifying when the but for test is applied to an omission. In the case of omission, “but for the omission in question” means “if a legal duty imposed on the defendant had been carried out”, and thus the application of the but for test involves the consideration of a hypothetical event, that is, the performance of the relevant legal duty not actually done.
10 Though this sort of proof will be extremely hard, if not impossible.
11 Mitsuo Okano, “‘Joukenkankei’ Sonpinohandan” (1981) The Law School 29, 41.
12 Herring, above n2, 102.
13 Cane, above n2, 120.
have no factual connection with the consequence, no question of legal
causation will arise. This may result in cases contrary to common
Therefore, the but for test needs to be applied strictly in order not to allow
wrongful conduct to slip easily through the
meshes set up by that test.
By contrast, the first approach does not regard the but for test as a
necessary requirement, nor does it consider that test to be
factual causation. Rather, it views the test as a formula which merely expresses
a certain sort of relationship between
the conduct and the consequence.14
As such no problem will arise if the but for test is applied in a relaxed
way. This view has an advantage in that, in applying the
but for test, it
will never encounter troublesome problems discussed below which may stump
the other approach.15 However, if the factual relationship between
the conduct and the consequence, which is to be made out by applying the but for
“is actually not a species of causation at all”16
and not a necessary requirement for showing causation, why is the but for
test employed in considering a problem of causation? There
seems to be no cogent
The purpose of causal enquiry is to determine whether the very consequence
that has been brought about can properly be attributed
to the defendant’s
conduct, and the purpose of applying the but for test is to determine whether
there is a connection as a
matter of fact between that consequence and the
conduct; accordingly, what needs to be brought into question should not be
a consequence in general or abstract terms defined in the relevant provision
but the specific consequence that has actually occurred.
B. The need for modification or substitution
1. Application to an omission
14 Simester and Brookbanks, above n1, 58.
15 This view, however, will have to deal with such problems at the
next stage, that is, where enquiry for legal causation is made.
As previously mentioned,17 the application of the but for test to
an omission entails consideration of a hypothetical event which did not occur.
This is also
the case with the second, rigorous approach above. Since “but
for the omission” means “if a legal duty imposed
on the defendant
had been performed”, it is inevitable that the execution of the relevant
legal duty not actually carried out
should be hypothetically considered.
2. Application to the unlawful act of driving without a
Further, there seems to be at least one case in which the but for test itself
needs qualifying. This may occur where the actus reus
comprises conduct and
those circumstances which bear on the quality of the conduct.18 The
argument which has recently been made is of manslaughter. In R v
Hawkins,19 for example, D caused the death of V while driving a
motor vehicle while in the throes of an epileptic seizure and was charged
with unlawful act manslaughter.20 D had driven without a
driver licence when she was subject to epileptic fits. Goddard J held that, even
if D had had a licence,
the accident would have occurred; that the unlawful act
of driving without a licence was thus not causative of V’s death; and
D’s susceptibility to epilepsy did not transform that act into a causative
The provision for unlawful act manslaughter, which is designed to prohibit
strictly an unlawful act likely to do harm to others, imposes
on the accused
criminal liability for the death where the accused prosecuted such an act
and someone’s death ensued.
It condemns unlawful acts, not lawful acts,
when they have brought about death. It follows that, insofar as that provision
what counts as to causation is the fact that death occurred
because the conduct in question was unlawful. The aim of forbidding unlawful
activities to protect human lives can well be achieved by requiring causation
between death and
17 See above n9.
18 For a more detailed discussion on this matter, see Kevin Dawkins and Margaret Briggs, “Criminal Law”  NZ Law Rev 570-576 (Dawkins).
19 R v Hawkins 21/2/01, Goddard J, HC Napier T18-00.
20 Section 160(2)(a) Crimes Act 1961.
unlawfulness of the accused’s conduct.21 If so, the but for
test can be modified as follows: would the consequence (that is, death) have
occurred but for the unlawfulness22 of the accused’s conduct,
or the fact(s) laying foundation for the unlawfulness of it? As in the case of
above, this application of the but for test entails the
consideration of hypothetical conditions which did not happen or exist.
The act of driving is lawful when the driver holds a licence. In the case of
driving without a licence, therefore, the application
of that modified test
involves hypothetical consideration: would the victim have died if the defendant
had had a licence when driving?
Where, as in Hawkins, D is charged with
unlawful act manslaughter when D, driving a motor vehicle while in the
throes of an epileptic seizure,
killed V, if the accident was brought
about owing to that medical condition, it can be said that V’s death would
had D been driving with a licence. Unlawfulness of D’s act
of driving was causally irrelevant to the death.
Even if the but for test is applied without modification and but for
causation is established, legal causation could be denied if
the way of applying
the test for legal causation (i.e. “operating and substantial”
test23) is adjusted so that it will be applied to unlawfulness, or
those facts which render the conduct unlawful. In the above case of driving
without a licence, the normal test will ask if the act of D’s driving
without a licence was an “operating and substantial”
V’s death; whereas the adjusted test would ask if the absence of a licence
while D was driving was an “operating
and substantial” cause of
V’s death. The answer to the former question is probably yes. This is
because, as was held
in Hawkins, D’s election to drive when
suffering from a medical condition that could adversely affect D’s ability
to drive safely
may be said to be an operating and substantial cause of
V’s death, but the act of D’s driving itself also made an operating
and substantial contribution
21 Unlawfulness of the conduct in question turns on whether there are facts rendering the conduct unlawful.
22 Not the unlawful conduct itself.
23 Herring, above n2, 103; R v Myatt  1 NZLR 674 (CA)
to the death. What would have made no difference was whether or not D had a
licence when driving. Thus, the absence of a licence cannot
be regarded as an
“operating and substantial” cause. It is causally immaterial, and
the answer to the latter question
3. Application to the case of alternative
Where simultaneous acts appear to be contributing to the result, mechanical
application of the but for test may lead to a conclusion
contrary to our common
sense.25 A classic example is as follows:
Case 1 D1 added a lethal dose of poisonous drugs to V’s cup of coffee. As it happened, D2, without conspiring with D1, also added a lethal amount of poison to the same cup. V, unknowingly having the toxic coffee, immediately
Another hypothesised scenario may be compared to this:
Case 2. The same as above, except that both the poison D1 added and
the poison D2 added were half the lethal dose.
Another scenario which may be contrasted with both Case 1 and Case
2, is as follows:
Case 3 The same as Case 1, except that the poison D2 added was half
the lethal dose.
Case 2 is the easiest to tackle. Because both the poison D1 added and the
poison D2 added were half the lethal dose, it can be said
that but for adding
the poison by either of them, V would not have been killed. It follows that but
for causation is established
both between D1’s act and V’s death and
between D2’s act and V’s death.
24 For a general discussion on this point, see Seiji Saito, “Iwayuru ‘Takuitsutekinakyogo’
womegutte” (1980) The Law School 24, 96-102.
25 This point is often made in tort law. See for example March
v E  HCA 12; (1991) 171 CLR 506 (HCA), 516 (per Mason CJ).
Case 1, by contrast, has been considered to be the toughest to deal with. The
mechanical, relaxed application of the but for test
will surely negate but for
causation both between D1’s act and V’s death and between D2’s
act and V’s death.
On the other hand, according to the view which looks at
the particular consequence that did occur, but for causation can be established
both between D1’s act and V’s death and between D2’s act and
V’s death if, and only if, it is proved that
the poison they added
combined together and, even slightly, hastened V’s death
More troublesome are cases in which the prosecution failed to prove beyond
reasonable doubt which poison actually had the fatal effect
on V or the
prosecution successfully proved beyond reasonable doubt that no difference would
have been made in when and how V died
had only either D1 or D2 participated.
When considering these cases, one needs to bear in mind the following
(1) The defendant ought to incur criminal liability for his or her own conduct; but
(2) The prosecution must prove causation beyond reasonable doubt. One policy
reason underlying this principle is the notion that the
defendant ought not to
incur criminal liability for another person’s conduct unrelated to him or
In light of (2), there is no way but to acknowledge that but for causation cannot be found either between D1’s act and V’s death or between D2’s act and V’s death where the prosecution failed to prove which poison actually had the fatal effect on V. This conclusion must be accepted in New Zealand if one recognises that “[n]o concept is more important to the criminal law than the requirement of proof of guilt beyond reasonable doubt”.27
Then what if the prosecution successfully proved beyond reasonable doubt that
no difference would have been made in when and how V
26 This means that there is no complicity between the defendant and the other person.
27 Kevin Dawkins and Margaret Briggs, “Criminal
Law”  NZ Law Review 137.
died had only either D1 or D2 participated?28 The same question
will arise where, for example, D3 and D4, without conspiring, fired at V and the
bullets happened to enter the heart
of V at the same time, who was killed
instantly (Case 4). If the but for test is applied to D1 and D2 individually or
D3 and D4 individually,
but for causation cannot be established between any of
the defendants and V’s death because but for the conduct of D1 or D2,
of D3 or D4, V would have been killed at the same time in the same way.
On reflection, though, it is because D2 or D4 did an act sufficient to kill V
that but for causation, by applying the but for test,
cannot be established
between D1’s or D3’s conduct and V’s death, and vice versa.
This indicates that there can
be factual causation found between the act of at
least either of them in each case and V’s
Here lies a quandary. The point (1) mentioned previously that the
defendant ought to incur criminal liability for his or her
conduct would lead to
the conclusion that at least D1 or D2 in Case 1 and D3 or D4 in Case 4 ought
to bear responsibility for
V’s death because there is factual
causation between the act of either of them and V’s death.
However, there is no way to choose which one should incur the responsibility.
Proposition (1) needs to be read in conjunction with
the principle (2); that is,
it is only when the prosecution have proved causation beyond reasonable doubt
that the defendant may
be held criminally liable for his or her conduct.
Although there may be factual causation between the act of either of the
defendants and V’s death, the prosecution cannot prove
doubt that one act, not the other, is of causal relevance to the result. It
follows that factual causation has
to be negated both between D1’s conduct
and V’s death and between D2’s conduct and V’s death in Case 1
both between D3’s shooting and V’s death and
28 For the criticism that such a phenomenon can never physically happen, see Yasushi
Ito, Mitsumasa Matsuike, Koichi Kawaguti, and Rikizo Kuzuhara, Keihokyokasho Souron
(Jo) (Tokyo, Saganoshoin, 1992) 157-158 (Mitsumasa Matsuike).
29 Leaving aside the matter as to whether to call this but for
D4’s shooting and V’s death in Case 4.
This conclusion, however, has been regarded as absurd, generally for the
following two reasons.30 Firstly, each of the defendants did a
dangerous act which was sufficient to kill V. Secondly, imbalance arises between
Case 1 and
Case 2, where, though D1 and D2 prosecuted a less dangerous act than
in Case 1, but for causation is established between D1’s
coffee and V’s death and between D2’s poisoning the coffee and
For those reasons, it has been argued that the but for test should be
modified to cope with that problem. The modified version of
the but for test is
as follows: where there are some acts or omissions, any one of which is
sufficient to cause the particular consequence
in question, but for causation is
established if, but for all of them, that consequence would not have
occurred.31 If this modified but for test is applied, since V’s
death would not have occurred but for the poisoning of the coffee by D1
in Case 1, or the shooting by D3 and D4 in Case 4, but for causation can be
established in relation to any one
of the defendants.
However, this view has met with the sharp criticism that no theoretical
ground is shown which enables all the relevant acts or omissions
to be seen
in toto. Unlike where the defendants are joint principals, where they are
not, they acted or omitted independently, and therefore their acts
cannot be viewed as a whole.32 In the above cases, D1 is not
associated with D2, and thus the poisoning of the coffee by D1 and by D2 cannot
be taken collectively;
D3 is not associated with D4, and thus the shooting by D3
and by D4 cannot be taken collectively, with the result that there can
be no but
for causation established.
To the argument that this conclusion would create imbalance between
Case 1 and Case 2, the following counter-argument is possible. For
30 See for example Oya, above n8, 221.
31 For example, Oya, above n8, 222; and Masahide Maeda, Criminal Law: The General Part
(4th ed, Tokyo, University of Tokyo Press, 2004) 221.
32 For example, Saku Machino, Keihosoronkogian I (2nd ed,
Tokyo, Shinzansha, 1998) 157.
purpose of constructive discussion, it is useful to focus on the conduct of
D2. In Case 1, both D1 and D2 added a lethal dose of poison.
In Case 2, it is
true that D2 added only half the lethal dose of poison, but D1 also added only
half the lethal dose; that is, circumstances
unrelated to D2 differ between Case
1 and Case 2.33 This difference defies meaningful comparison.
It is between the conduct of D2 in Case 1 and of D2 in Case 3 that the right
balance should be achieved. Since conditions unrelated
to D2 do not differ
between Case 1 and Case 3, it can well be said that imbalance would arise if
D2’s criminal responsibility
was lighter in Case 1 than in Case 3. In Case
3, but for causation can be established between D1’s poisoning the coffee
V’s death because but for D1’s poisoning the coffee V would not
have been killed. However, as between D2’s poisoning
the coffee and
V’s death, unless the prosecution proved beyond reasonable doubt that the
poison which D1 and D2 added combined
together and, even slightly, hastened
V’s death accordingly, but for causation cannot be established.34
In light of this conclusion, it cannot be said that there is imbalance
between Case 1 and Case 3 in D2’s criminal responsibility
because it is
not lighter in Case 1 than in Case 3.
The problem is that no one will incur liability for V’s death in Case 1
and in Case 435 if the unmodified but for test is maintained, though
all the defendants did a dangerous act which was sufficient to kill V.
To avoid this problem, it is necessary to replace the but for test36
or relinquish enquiry for factual causation itself.37 The
former would be
33 Atsushi Yamaguchi, Keihosoron (revised ed, Tokyo, Yuhikaku, 2005) 50 at n19.
34 Though it might be argued that the but for test should be modified here as well as in Case 1 and in Case 4. However, such a modification is unnecessary in Case 3 because there is at least one defendant (ie D1) who will bear criminal liability for V’s death.
35 Though all the defendants will incur liability for attempted murder.
36 See, for example, Wright, above n5, 1018-1042; and Keiichi Yamanaka, Keihosoron I
(Tokyo, Seibundo, 2000) 251-253.
37 Smith and Hogan, above n6, state that the principle of but for
causation may have exceptions and that “[i]t seems safe to assume
and D2 in Case 1, and D3 and D4 in Case 4] will be held to have caused”
the death of V (n14 at 43), but no theoretical
basis is shown.
impracticable because New Zealand law appears to be more interested in
argument based upon common sense than argument based upon theory.
practicable approach would thus be the latter.
Unlike civil law countries such as Japan, in New Zealand the test for legal
causation is not logically premised on factual causation. The general
principle in Japan is that causation in law will only be established if, on the
on which factual causation has been found, according to the
experience of ordinary people, the consequence could be regarded as natural,
not unusual.38 For example, where D3 and D4, without conspiring,
fired at V’s heart and only D4’s bullet hit V, who was killed
there is no factual causation between D3’s shot and V’s
death, and the question of legal causation will never arise between
answer can in theory be provided as to whether there is legal causation where
there is no factual causation proved, upon
which legal causation could be
established. An absurd conclusion would be reached if it was possible to make
enquiry for legal causation
without establishing factual causation. In the above
case, since, according to the experience of ordinary people, it is not unusual
for a person covered with a rifle to be killed if the offender aimed at the
person’s heart and shot, legal causation could
be established between
D3’s shot and V’s death, if enquiry for legal causation did not have
to be premised on those facts
on which factual causation has been shown. Notice
may need to be taken of the fact that the Japanese test for legal causation has
been derived from German law and has theoretical foundations.39 The
question of causation arises at the stage of Tatbestand,40
38 For further details, see for example Humiaki Uchida, “Sotoingakankeisetsuniokerusotoseino
‘Handankijun’ to ‘Sotosei’” (1981) The Law School 29, 15-23.
39 For a causal theory of German law, see Hart and Honoré, Causation in the law (2nd ed, Oxford, Clarendon Press, 1985) Chapter XVII.
40 The difference between the criminal law systems of New Zealand and Germany defies the comprehensive translation of the concept Tatbestand into English. Roughly speaking, in German criminal law, determination of whether an act or omission constitutes a relevant crime involves three stage enquiries: (1) whether the act or omission falls within the definition of the offence; (2) whether the act or omission can be justified; and (3) whether the defendant can be excused. Tatbestand covers the question (1) and thus could be translated into the “definition of an offence” (see George P Fletcher, “Criminal Theory in the Twentieth Century” 2 Theoretical Inq L 265,
237). Tatbestand, however, could mean more. An offence is codified to
prohibit certain conduct which should be viewed as illegal; accordingly, an
or omission which has
which has been derived from German law and is unknown to New
Zealand criminal law.
In New Zealand, enquiry for legal causation, whether or not it is based on
the facts on which factual causation has been established,
would lead to the
identical conclusion. In the above example, since D3’s shot did not make
an “operating and substantial”41 contribution to
V’s death, legal causation could not be established between D3’s
shot and V’s death even if the
application of the but for test was
C. Relinquishment of the but for test
The test for legal causation (one standard being an “operating and
substantial” test) in New Zealand can be said to cover
the test for
factual causation. Apart from the cases of alternative concurrence (i.e. where
there are some acts or omissions any
one of which is sufficient to cause the
particular consequence in question), where the defendant’s conduct can be
said to have
made an operating and substantial contribution to the consequence
in question, it can also be said that but for it the consequence
would not have
occurred when and as it did. The but for test is also unnecessary in those cases
involving intervening events or acts
in which the above test does not fit.
Relevant principles such as a “reasonable foreseeability”
test42 and a “free, deliberate and informed” test43
may be said to cover enquiry for factual causation. This is because an
intervening event or act which is reasonably foreseeable or
deliberate and informed” may properly be
passed through the first stage enquiry and falls within the relevant definition will at least be deemed as prima facie illegal. Therefore, although it could mean more, Tatbestand may be said to denote constituent elements, mental and physical, of the offence, the satisfaction of which indicates that at least the conduct in question is prima facie illegal. This function which Tatbestand serves is reflected in the way in which causation should be examined. For a general discussion on this point, see Noriyuki Nishida, “Koseiyokennogainen” in Noriyuki Nishida and Atsushi Yamaguchi (ed), Keihonosoten, (3rd ed, Tokyo Yuhikaku, 2000 ) 14-15.
41 Herring, above n2, 103; R v Myatt  1 NZLR 674 (CA), 682-683.
42 Simester and Brookbanks, above n1, 61; Robertson (ed), Adams on Criminal Law
(Wellington, Brookers, 1992) CA158.10 (looseleaf).
43 R v Pagett  EWCA Crim 1; (1983) 76 Cr App R 279, 288 (per Sir Robert Goff LJ, citing Hart and
Honoré (1st ed), above n39).
viewed as depending on a defendant’s initial
conduct.44 The dependence of the intervening event or act upon
the defendant’s initial conduct demonstrates the existence of but for
between the defendant’s conduct and the result: but for the
defendant’s initial conduct, the result would not have been
by the intervening event or act at the same time in the same way. Therefore,
except for those anomalous cases above,
legal causation can rightly be
considered even if enquiry for factual causation has been skipped.
Further, since the test for legal causation is not logically premised on
factual causation, enquiry for factual causation can be omitted
well. There is thus no need to stick to enquiry for factual causation.
Enquiry for legal causation involves a value judgment, the question being
whether the consequence can fairly be “imputable”
defendant.45 Such cases as Case 1 and Case 4 above could well be
dealt with at the stage of legally causal enquiry which may entail evaluative
considerations. Even if a factually causal enquiry has been omitted, these cases
could rightly be considered. Here, the question
is which of the two alternatives
is more just: to hold each defendant liable for V’s death, or to hold
neither of the defendants
liable for the death.46 Policy argument is
more suitable at this stage about, say, what objects are to be achieved by the
penal code. If, for example, one
thinks criminal law exists to prevent
particular consequences defined in the relevant provisions from occurring by
provided explicitly or implicitly in them, it would be
futile, for this purpose, to blame a
44 Simester and Brookbanks, above n1, state, in the context of an intervening act by a
third party, that “in law, [the intervention which is not “free, deliberate and informed”]
has the status of being itself a consequence of D’s wrongdoing” (at 63).
45 Williams, above n4, 381.
46 Simester and Brookbanks, above n1, assert that “[f]rom a moral and legal perspective, no other conclusion [than the former] is possible, even though this type of case presents difficulty for philosophical accounts of causation” (n94 at 60). However, as is shown in the text, the latter conclusion is also possible from a legal perspective (see Makoto Ida and Masao Maruyama, Case study keiho (Tokyo, Nihonhyoronsha, 1997)
85). Arguably, one could reach either conclusion by applying the
“operating and substantial” test in accordance with one’s
value judgment. That being the case, this test can be said to lack objectivity
in the anomalous cases of alternative concurrence.
defendant for that consequence which could not have been prevented had the
defendant refrained from his or her conduct. It is only
where a defendant
perpetrated an act and brought about a prohibited result when he or she could
have prevented it by not acting as
he or she did that the imposition of criminal
liability for the result can be justified for that purpose. If the consequence
an unavoidable one (that is, if it would have occurred had the defendant
refrained from acting as he or she did), it would not
serve that purpose
to ascribe it to the defendant.47
The but for test is a useful means to determine whether there is factual
causation between the defendant’s conduct and the consequence.
To do so
correctly, however, it needs to be applied to that act or omission which falls
within the particular actus reus; and the
consequence viewed in concrete terms
rather than in the abstract.
The test for legal causation can be said to cover the but for test as
properly applied. Enquiry for factual causation can theoretically
be skipped as
well. Further, since legal causation is not logically premised on factual
causation, enquiry for factual causation
can be skipped theoretically as well.
Therefore, there is no need to stick to enquiry for factual causation. What
the law is not whether there is a logical but for
relationship between the defendant’s behaviour and the prohibited
consequence, but whether there is a true causal relationship
law”.48 The proof of but for causation need not be
required as a separate requirement for the establishment of
conclusion would enable the courts to escape theoretical,
endless argument over the modification of, or substitution for, the but
47 Makoto Ida, “Ingakankeinoriron” (1999) Gendaikeijiho 4, 62-63. Although the author makes this argument at the stage of enquiry for factual causation, in New Zealand his reasoning is also applicable to the next stage of enquiry for legal causation where policy can be an overriding consideration.
48 Simester and Brookbanks, above n1, 58 (emphases