Another difference between legislation and treaties is that the scope of applica-
tion of legislation will usually be confined to the territory of the legislating state,
while treaties will normally deal with international relations or, at least, cases that
are not limited to national borders.
Human rights, for instance, do not only concern the relationship between human beings and
the state on whose national territory they happen to be, but also those between human
beings and other agents in general, including states.2.5 Case Law
As a source of law, the decisions of courts play a role that is somewhere in between
being merely a source of origin and a source of validity. We have seen above that
legal decisions for concrete cases tend to influence future decisions because they
function as a kind of precedent.
2.5.1 Civil Law Tradition
Like Cases Alike In the civil law tradition, where a precedent does not officially
bind courts, the influence of earlier decisions will depend on at least two factors.
One factor is the demand of justice to treat like cases alike.If one case has been
decided in a particular way, it is often assumed that it is unjust to treat a subsequent
case, which is deemed similar in all relevant aspects, in a different way.
It is not immediately clear where this alleged injustice lies. The most plausible reason
would be that the law has not changed between the two cases. If the first case was decided
correctly, then the second case should be decided similarly, because the law is still the
same. This would be a matter of logic, though, and not so much of justice.Rationality A strongly related reason is the rationality of the earlier decision. If
the earlier decision was rational, and especially if this rationality is clear from the
way in which it was argued, a departure from this earlier decision in a new similar
case would be irrational.
Legal Certainty The second factor is the demand of legal certainty.If an earlier
case was decided in a particular way, this may create expectations among legal
subjects with regard to the contents of the law and the way in which future cases
will be decided. To give a different decision in a future case not only would be a
violation of these expectations but also would create uncertainty that is detrimental
to the functioning of society.
Suppose that someone sold a sick cow and expected, on the basis of an earlier judicial
decision, this to be an irreversible sale because the buyer could have seen that the cow was
sick. The seller therefore could proceed to use the money he received from the buyer to buy
a new calf. If it was possible for the sale to be reversed, this might bring the seller into32 J. Hage