Causation in Modern Law.
In modern law, legal
personality has expanded to include almost all
adult
human beings, but liability is curtailed in comparison
with the
broad coverage usually attributed to primitive
law. Today, common learning
states that defendant
cannot be charged with responsibility for a
wrong
unless his conduct has physically caused the wrong and
unless
the law deems this cause to have been proximate.
The
use of the idea that among all the physical ante-
cedents of an event, one or a few may be discerned
as
“proximate” is apparently due to medieval philoso-
phers, notably to Saint Thomas
Aquinas. Its use in
English law is usually laid to Sir Francis Bacon:
“The
law looks to the proximate, and not to the remote
cause” (In jure non remota causa, sed proxima
spec-
tatur; Maxims, Reg. I
[1596]).
In the nineteenth century, English and American law
used the idea of
causation, primarily in tort law, as
a means of restricting responsibility
for the growing
rate of accidents and the large amount of property
damage accompanying the industrial revolution. In the
early cases,
causation and other devices, especially the
doctrines of intervening cause,
contributory negli-
gence, and voluntary
assumption of risk, served to
relieve from liability many of those who in a simple
agricultural system would normally be held responsible
for loss
of life or damage to property that resulted from
their acts. Naive ideas of
physical causation alone
would have saddled growing industry and trans-
portation with most of the
responsibility for the harms
flowing from these activities. It was in this
emergency
that notions of proximate causation and
intervening
cause were invoked, and harmful behavior which nor-
mally might be taken as the physical cause
of injury
was increasingly held not to have caused the injury
“proximately” or not to have been a
“substantial fac-
tor” in
the injury or not to have been the “natural
and probable
consequence” of the defendant's acts.
Hence arose the important
distinction between physi-
cal causation and
legal causation which has been the
subject of thousands of decisions in all
the advanced
industrial countries and particularly in England and
in
the United States.
The idea of physical causation has been enriched
by scientific learning on
the nature of cause. In the
eighteenth century, the idea of physical cause
and
effect as a phenomenon of probability made itself felt
in the law.
Particularly in the matter of proof, the law
began to accept the notion
that a given cause can never
unequivocally be assigned as the responsible
agent of
an effect, but at best only a probability judgment can
be
made. This learning was revived in the twentieth
century and cases and
commentaries began to state
physical causation in terms of probability
theory.
At best, physical causation came to be recognized
as only a conditio sine qua non of liability. If plaintiff
is unable to establish physical causation, then this view
holds he is
subject to non-suit. If plaintiff does establish
physical causation, then
he must go on to show that
the defendant's harmful conduct was the
“proximate”
or “legal” cause of
the injury. Causation in law thus
became a matter of legal policy, a device
for selecting
out those chains of physical causation to which
liability
would or would not attach. Causation in law came to
be
frankly recognized as legal policy; not causation
at all but judicial
policies respecting liability.
Examination of cases shows that for the same series
of acts, liability may
be held to be based on causation
or not, depending upon whether the
defendant is found
to have intended the harm, has been negligent, or
is
innocent of any wrongful state of mind. This seemed
to show not
causation, but a judicial policy of assessing
liability on the state of
mind of the defendant rather
than on the chain of causation set up by his
conduct.
Numerous other policies, such as liability for ultra-
hazardous activities, or for faulty
products are cast in
terms of causation.
Contemporary learning on causation has a very ex-
tensive examination in a recent work called Causation
in the Law by H. L. A. Hart and A. M. Honoré.
The
authors espouse the theory that causation in law is an
essentially
nonphilosophical, profession-oriented de-
vice,
heavily charged with common sense ideas on
current meanings of causation.
Paradoxically, it takes
a philosophical theory (the “ordinary
language” philo-
sophical
outlook) to establish this thesis. The idea itself
is old, and arises not
only from a general antiphilo-
sophical bias extant from Roman law times, but in the
nature of the
case from the way in which philosophical
ideas become homogenized with a
discipline that ab-
sorbs them. We should not
take too seriously the pro-
testations of
experts in the field of causation in law
that their special doctrines have
little to do with phi-
losophy.
“The lawyer cannot afford to adventure him-
self with philosophers in the logical and metaphysical
controversies that beset the idea of cause,” says Sir
Frederick
Pollock (1887). However, we must remember
that it is the normal fate of
philosophy as the parent
of the sciences to suffer repudiation by its
children.
A very sophisticated formulation of the nature of
legal causation relying
explicitly on the philosophy of
science is found in the work of Morris and
Felix
Cohen (Cohen and Cohen, 1951). Of peculiar interest
is Felix
Cohen's application of field theory and cultural
relativity to the notion
of causation in law (1950).
Legal causation is concerned not only with the ques-
tion of who or what caused harm, but also with the
extent of harm to be attributed to the defendant's
act.
A man's careless toss of an unextinguished match may
burn down an
entire ship and her cargo. Since almost
all modern theory on legal
causation has centered on
the law of negligence, the issue comes to be
framed
as one of determining whether the defendant should
have
foreseen that he was creating an unreasonable
risk of harm. This thought
construct, “the reasonable
man,” is created and
endowed with a set of physical,
psychological, and moral awarenesses and
responses
that correspond to average opinion, as seen by courts
and
commentators, on how a reasonably prudent per-
son of ordinary ability should conduct his affairs.
At times, this reasonable man turns out to be singu-
larly obtuse; at others he is charged with almost divine
prescience. Writers on legal causation attempt both to
shape the course of
legal decision on the basis of a
rich conglomerate of causation theories,
and, after the
fact, try to analyze out of the cases principles of deci-
sion which they offer as guides to future
developments
of the law.
The law of negligence is the birthplace of all modern
sophisticated theories
of causation. From there, the
theories diffuse throughout the rest of the
law of torts,
thence to contracts, particularly on the question of
extent of damage to be attributed to a breaching de
fendant, and to the law of crimes, where, not the extent
of
harm, but the relation between the forbidden harm
and the criminal conduct
is the issue (Hall, 1947).
