in all the relevant aspects. This creates leeway for the development of law because a
court that must decide a new case has to determine whether the new case is really
similar to the alleged precedent. By pointing out relevant differences
(distinguishing), the court can argue that the cases are not similar and that it is
not bound by a particular precedent.
Suppose, that the seller who sold a sick cow explicitly stated to the buyer that the animal
was healthy. Would that make a difference to the buyer who bought the cow and who wants
his money back? If the court decides to distinguish this case from the prior case, the law will
be changed, because this decision will also function as a precedent for future cases.Broadening It is possible that a court treats cases as similar when their similarity
was not obvious. This is called “broadening.”
If a judge applies the rule that there will be no money back for unhealthy animals if their
illness was detectable to a case involving defective products bought in a shop, the rule will
be broadened considerably. This broadened rule will also come to function as a precedent.
Common law grows because the number of cases from which it results grows. In
a sense, common law consists of the combined effects of all these previous cases.
However, there are no clear rules because common law reasoning is not a matter of
applying clear-cut rules but rather a matter of analogizing precedents. A new case
has to be decided in a particular way, not because of a rule that was established in
earlier decisions but because the new case is similar to an earlier case that was
decided in that way. At least, that is the theory. In practice, lawyers distill rules from
the body of precedents, and these rules are described in textbooks, where they are
substantiated by reference to the cases in which they were adopted asrationes
decidendi. These textbooks function as a knowledge source for common law, but it
is the precedents that function as the validity source.
Restatement One step further than the summary of case law by means of
textbooks is a restatement of the common law on a particular topic. Such a
restatement, which is the work of legal scholars, is also a description of the rules
on a topic, but it has a semiofficial status that is comparable to other forms of soft
law. Courts are not bound to adopt the rules from a restatement as the law, but they
often do because these rules accurately restate the already-established law in that
jurisdiction.
In the USA, the American Law Institute, an organization of legal academics and
practitioners, has drafted restatements of the US common law on more than twenty
subjects.2.6 Customary Law
Usus Probably the oldest source of law is customary law. It is usually assumed that
two conditions must be met so that we can speak of customarylaw. The first
condition is that there must be acustomconcerning a guideline for behavior. This
34 J. Hage