CAUSATION IN LAW
While causation is an idea of general consequence
in religion and philosophy, it is a term of more special-
ized meaning in science, in history, and in law.
In
science, causation is largely a principle of explanation
and
prediction. For history, when admitted at all, it
is a vast abstraction
that succeeds only minimally in
ordering the complexities of observed human
behavior.
In law, the idea is at once highly theoretical as the
most
general justification for the imposition of liability,
and severely
practical as a means for assigning legal
responsibility in the individual
case. Law views causa-
tion as related both to
the order of nature and to the
nature of justice. In the first, causation
plays a central
role in the determination of legal facts; in the
second,
causation emerges as a leading component of the idea
of responsibility. Each of these roles is indefinitely
complex.
Their combination is the history of the idea
of causation in law.
Law and Religion.
Causation is a leading motif in
most religions: the ways in which the
world comes into
existence and is sustained, and the modes by which
man may discharge religious obligation. Each notion
involves a theory of
causation. A religion's cosmology
issues in its science, primitive or
advanced; the obliga-
tions imposed on man
by his religion are his first law.
All the ramifications of the idea of
causation in religious
history have this dual character. Causation is
either
physical or purposive, according as its referent is na-
ture or human conduct. Causation in law retains
the
two strands, though its concern is much more with
human action
than with the order of physical events.
In the history of Western religion, God is said to
have caused the world to
come into existence and to
govern it through his laws (note the legal
reference).
In the Bible, the cosmogonic account of the origin of
the
universe is scant and primitive; the laws governing
man are detailed and
sophisticated, so much so that
the original document comes to be known as
the Book
of the Law (Torah, in Hebrew). There was an early
development
of a widespread casuistic activity which
has never ceased to occupy the
Hebraic religions.
Religious law concerns itself with the limits of
human
obligation or responsibility, and inherent in all such
legislation or decision is a notion of causation. It is
usually assumed
that a man is responsible for the state
of affairs which he has caused. The
extent to which
he may be held responsible for events he has not
caused
is a matter of deep and continuing perplexity.
Out of this religious practice grew one major strand
of the idea of
causation in law. And since law becomes
separated from religion, if at all,
only in the late matu-
rity of religion, it is
easy to see how important religious
beliefs in the matter of causation are
to legal develop-
ment. In brief, religion
bequeaths to law the notion
of moral responsibility for man's interventions
in the
regular course of nature and for impositions of his will
upon
nature and society. It may or may not hold him
responsible for what he does
in a state of divine mad-
ness, atē, karma, or fate. “Not I was the
cause of this
act,” said Agamemnon, “but Zeus and the
Erinys who
walks in darkness: they it was who in the assembly
put wild
atē in my understanding, on that day when
I arbitrarily took
Achilles' prize” (Dodds, 1957). A
modern pleader might say,
“Not guilty because of
temporary
insanity.”
Law and Philosophy.
All philosophical systems sub-
scribe to
some central idea of causation. In philosophy
as in religion, the notion of
causation is either physical
or purposive, or both. At times a mechanistic
or deter
ministic theory of causation is held applicable to the
whole of
nature, including man. At others, nature is
seen as a total purposive or
teleological structure. In
the philosophic beginnings of Western culture,
that is
to say, in the teachings of the Pre-Socratics, there is
much
evidence that the order of nature is seen as a
regime of legal obligation.
“... Anaximander's doc-
trine of the
systematic justice of the universe reminds
us that the most important idea
in the new philosophy,
that of Cause (aitía) was the same as the idea of Retri-
bution and was transferred from legal to physical ter-
minology” (Jaeger, 1945).
Justice rules the world and
the seasons must repay their just debts.
In classical antiquity, apart from the materialistic
atomists, man and
nature are clearly separated and the
emphasis shifts from a philosophy of
nature to a phi-
losophy of human nature.
Theories of causation become
full-fledged, and philosophy starts on the
task of ampli-
fying an account of this
process which it has never
wearied of. Aristotelian and Stoic ideas of
moral obli-
gation entered into Roman
cultural life and indirectly
exerted a great influence on the course of the
develop-
ment of the Roman Law.
Apparently, however, Greek
philosophical notions of causation had little
effect on
Greek legal practice, which indeed never developed
a system
of general jurisprudential ideas. “Why were
Greek philosophy and
Greek law so little influenced
by each other?” (Jones, 1956).
Indeed, even Roman
jurists, as distinguished from the philosophers,
appear
to have resisted philosophic “indoctrination”
until the
end of the classical period (Schulz, 1953).
The Aristotelian doctrine of causation went over into
the medieval religious
systems, both Jewish (B. Cohen,
1966) and Christian (Wigmore, 1912) and
entered inti-
mately into ecclesiastical law,
clerical and lay, partly
through the Canon Law and partly in medieval
Jewish
philosophy and rabbinical practice.
Modern philosophical theories of causation have had
a large though usually
indirect effect on modern juris-
prudence,
especially after the separation of law from
theology on the Continent, and
in the theories of phys-
ical and psychological
causation of Hobbes, Bacon,
Locke, and Hume in England. The rationalistic
epis-
temologies (Descartes, Spinoza,
Leibniz) tend toward
ethical determinism (Spinoza) or barely rescue
freedom
of will by a palpable device (Descartes). In Leibniz,
trained
lawyer and diplomat, the problem of legal
“conditions” was a matter of early concern, and in
Christian von Wolff (1679-1754) the whole deductive
apparatus of
rationalism was taken over bodily and
applied to the law. Strangely enough,
the rather so-
phisticated theories of
ethical determinism developed
by the rationalists found an echo in the
primitive
theory of legal liability that a man acts at his peril,
and that while religion may look tolerantly on the
ignorant
sinner, the early law shows him scant indul-
gence. Its motto was:
Qui inscienter peccat,
scienter
emendet (“Who unknowingly sins, knowingly
makes
amends”).
Of British empiricism, Hume's view of causation as
based on custom was most
congenial to the common
law jurists. Returning to the continent, the
Kantian
theory of causation has had but little effect on theories
of
causation in law. When we come to the nine-
teenth-century philosophical movements, we find that
theories of
causation, particularly those of the philoso-
phers of science (e.g., Bentham, Comte, Mill, Spencer)
reach the
daily practice of the law, if at all, only
through the screen of philosophy
of law or of juris-
prudence. In sum,
philosophy enables the legal philoso-
pher
or jurisprudent to amplify and adapt philosophical
theories of causation to
general systems of jurispruden-
tial
thought. These in turn stimulate legal specialists
or commentators and
eventually the ideas filter down
into legal practice.
In contrast to philosophic origins of causation, law
more often takes
account of ideas and sentiments of
causation as popularly conceived, even
when the law
does not find it necessary to deal directly with causa-
tion as a general juristic idea. And at
all times the law
is busily engaged in creating the materials out of
which
a body of learning on causation can be created. Begin-
ning with the nineteenth century, this body of
theory
comes into existence and jurisprudential ideas of causa-
tion enter directly into the everyday
life of the law.
Cause as a Term of General Significance.
The legal
word “cause” and the Roman law causa are terms of
ancient usage (Plucknett, 1956a).
These terms meant
(and still mean) variously the right which the
injured
party asserts, or the form of judicial redress, or the
justification by either party for his course of conduct.
Indeed, this idea
of cause, whose essence is caught up
in the ordinary word
“because,” is the primary and
ubiquitous meaning of
“cause” (Plucknett, 1956b). The
plaintiff or
petitioner pleads his “cause of action.” The
defendant is called on to “show cause” why the ma-
chinery of the law should not move against
him. In
the Civil Law and vestigially in the Common Law,
the plaintiff
may be required to establish a good
“cause” why a
promise should be enforced, as for
example in a gift made in contemplation
of death
(causa mortis). “Without
just cause” is a legal catch
phrase traditional with many forms
and modes of judi-
cial process.
Needless to say, these are pristine and basic meanings
of the term
“cause.” When, late in the development
of both
matured systems of law (common and modern
civil law), students of legal
theory attempted to form
a comprehensive theory of causation in law, they
framed the
idea of causation from three familiar fac-
tors.
These are physical causation; the subjective state
of mind of the agent in
pursuing a goal or purpose;
and the policies of the law underlying its
decisions in
awarding or withholding redress. These three elements
may
be stated as part of the plaintiff's prima facie
case.
He must show physical causation by the defendant. In
addition,
he may be called on to show that the defend-
ant intentionally or negligently caused the harm.
Finally, he may
have to demonstrate that it is the law's
policy to regard the defendant's
behavior as just
“cause” for redress.
The mode by which legal causation is differentiated
from causation as a
philosophical idea can be illustrated
simply. In law, if you cause an
injury, you may be held
responsible. Conversely, if you happen to be
held
legally responsible, the law is apt to say you
“caused”
the injury. Most of the apparently limitless
debate on
the nature of legal causation originates in this simple
conversion of the idea. There is little scholarly agree-
ment on the nature of legal causation. Opinion
ranges
all the way from the assertion that causation underlies
all
legal phenomena to the denial that causation is a
necessary or even a
defensible notion in the realm of
legal liability. In between these
extremes, causation
theories proliferate, and their examination and
defense
continues to be the subject of a vast literature in the
present century.
Causation in Law in Historical Perspective.
We
have seen that highly advanced systems of law such
as the
Greek and Roman were able to get along with
only the most primitive
theories of causation. This
invites a word of explanation. Greek juristic
practice
was at all times at the mercy of the vagaries of oratori-
cal appeal. Causation as a logical and
integral part of
legal responsibility received scant attention. The
Roman law, like the Common law, was a legal system
whose theoretical ideas
were shaped mainly in practice
and largely dependent on the exigencies of
the avail-
able forms of action. All that
Roman jurisprudence
seemed to need in terms of a general idea of
causation
was the rule that injuries that were compensable under
the
lex Aquilia had to be
“direct” (Thayer, 1929). All
else was taken care of
in the more informal procedures
of the edictal law.
The early common law is believed to have been a
system of strict liability
where the question of whether
the defendant intended the harm he caused or
was in
a negligent state of mind is irrelevant. Hence, only
physical
causation seems to be in issue. Such defense
is exceptional. The absence of
physical causation would
plainly show that the plaintiff did not know what
he
was about or was ignorant of who or what caused his
injuries. Primitive systems of law are apt to be particu-
larly harsh on one who starts up the
machinery of law
and does not prevail. Hence, physical causation,
while
always relevant, could largely be taken for granted.
Nor do the
primitive systems of law take much account
of purposive causation, that is,
the question of whether
the defendant intends the series of consequences
which
flow from his act or is culpably negligent in initiating
them.
Indeed, the whole question of causation is blan-
keted in primitive law either by the rigidity of its
procedures
or by the overwhelming importance it
attaches to responsibility as flowing
solely from im-
memorial and therefore
unexceptionable custom.
In the matured systems of law of the Western world,
legal liability begins
in tort and crime, which are
scarcely distinguishable. Legal capacity and
respon-
sibility rest in the
collective unit of the kin. It alone
is recognized as a legal entity and it
is responsible for
the harm caused by its members. Causation,
therefore,
is in the kin.
When the legal unit became the adult male citizen
or freeman the notion of
“collective” causation or
responsibility was
continued. For the head of the
patriarchal family was responsible for a
numerous
retinue of human beings who themselves had only
limited legal
personality. A large body of legal imposi-
tions developed against many who could in no reason-
able interpretation of the term be held to have
“caused” the harm.
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).
Conclusion.
Millennia intervene between the death
of a boy accidentally impaled
on a javelin hurled by
Olympic games athletes in ancient Greece and a mod-
ern spectator struck on the head by a flying
puck in
a hockey arena. But the determination of legal causa-
tion is still as difficult in either
case. Today the specta-
tor at the hockey game
is said to have “legally” caused
his own harm by
“voluntary assumption of the risk.”
The Greeks said
the boy caused his own death by
running upon the javelin.
Modern doctrine attempts to ease the burden of the
individual human being
immediately or directly caus-
ing injury by
shifting loss on those more able to pay
or more likely to be able to pass
the loss on by in-
surance and thence
ultimately to the consuming public
in the form of higher prices.
Thus we see that while physical causation is still
thought to be basic, it
is the notion of purposive causa-
tion, and of
legal policy (the law's purposes) that mod-
ern
lawyers think of when the idea of legal causation
comes to mind.
BIBLIOGRAPHY
B. Cohen, Jewish and Roman Law (New York, 1966),
Vol.
II, Ch. XVII, “The Principle of Causation.”
F. S. Cohen,
“Field Theory and Judicial Logic,”
Yale Law Journal,
59
(1950), 251-59. M. R. Cohen, The Meaning of Human His-
tory
(LaSalle, Ill., 1947), pp. 105-61. M. R. Cohen and
F. S. Cohen, Readings in Jurisprudence and Legal Philosophy
(New York, 1951), pp. 233-68. T. A. Cowan, Essays in
the
Law of Torts (Newark, N.J., 1961), pp. 12-18. 
E 
. R. Dodds,
The Greeks and the Irrational (Berkeley, 1951). K. Engisch,
Die Kausalität als Merkmal der strafrechtlichen
Tatbestände
(Tübingen, 1931). L. Green,
Rationale of Proximate Cause
(Kansas City,
Mo., 1927). Nicholas St. John Green, “Proxi-
mate and Remote Cause,” American Law Review,
4, No.
2 (Jan. 1870), 201-16. J. Hall, General Principles of Criminal
Law
(Indianapolis, 1947), pp. 256-66. H. L. A. Hart and
A. M.
Honoré, Causation in the Law (Oxford, 1959).
W.
Jaeger, Paideia: The Ideals of Greek Culture,
trans. Gilbert
Highet, 3 vols. (New York, 1939-44), Vol. I (2nd ed.
1945),
p. 158. J. W. Jones, The Law and Legal Theory
of the Greeks:
An Introduction (Oxford, 1956), p. 292. F. H.
Lawson, Neg-
ligence in
the Civil Law, with Introduction (Oxford, 1950).
C. Morris,
Torts (Brooklyn, 1953), Ch. VII. E . Nagel, The
Structure of Science (New York, 1961), Ch.
X. C. S. Peirce,
“Proximate Cause and Effect,” in
Baldwin's Dictionary of
Philosophy and
Psychology (London, 1901-05), II, 373.
T. F. T. Plucknett, A Concise History of the Common Law
(Boston,
1956a); idem, “Law,” Encyclopedia
Americana
(New York, 1956b), 17, 89. R. Pound, Jurisprudence, 5 vols.
(St. Paul, Minn., 1959),
IV, 508-25, has extensive references.
W. L. Prosser, The Law of Torts, 2nd ed. (St. Paul, Minn.,
1955), Chs. 8 and 9. F. Schulz,
History of
Roman Legal
Science (Oxford, 1953), pp. 69, 135, 295. Saint
Thomas
Aquinas,
Summa theologiae, Ia, 14,
13. J. B. Thayer,
Lex
Aquilia (Cambridge,
1929). J. Wigmore,
Select Cases on the
Law of
Torts (Boston, 1912), I, 764ff.
THOMAS A. COWAN
[See also
Law, Ancient Roman,
Common;
Legal Respon-
sibility.]
