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The case against love: A recent legislation on incest

Germany’s highest court
recently upheld the law making incest a criminal offence that can be prosecuted
with up to 2 years
. It thereby rejected an appeal from a man who has four
children with his sister. The pair fell in love when they met for the first
time at adult age, after being brought up separately. Last week,
the enforcement of the law, which would amount to 17 month in prison for the
man, has been delayed. He and his sister now await the decision of minister of
justice of the appropriate
federal state.
Prior to and following the
decision of the highest court there has been a lively debate on upholding a law
that for many seems nothing but a historical relict and lacking sound

The court gave three reasons that
in total are to justify the legal norm: Protection
of the family
, protection of sexual
self determination,
and protection
from hereditary diseases
. It is essential that the declaration of the court
only sees the protection of the sum of these legal goods as a sufficient
argument to justify the legal penalties.

The strongest, though most
controversial point, is the last one: the protection from
hereditary diseases. In the case under debate the pair already has four
children. Three of them are in foster care, two are handicapped. Leaving the
serious problems raised by classifying someone as handicapped aside, it is to
be noted that if this was the only point justifying the illegalness of incest,
a consistent law would require sanctioning all sexual acts in which the
probability to father handicapped children is raised as compared to some
standard. This standard might be the likelihood to have handicapped children within
averaged over the whole society or the likelihood for a single couple that, according
to current standards, counts as perfectly healthy.

The current law is
inconsistent in this respect as it allows partners of all ages to beget
children – although there is evidence that the likelihood for genetic defects
becomes enhanced with older parents. Also people with diseases known to
statistically enhance the chance of having handicapped children are not curtailed in their mating behaviour.


The other two points – the
protection of the family as well as of one’s sexual self determination – are
already protected by other laws. Moreover, in the particular case they were not
violated: Brother and sister were brought up in different families and met each
other for the first time in a grown-up age. And both fell in love. This is not
a singular incidence: Brother and sister who are not brought up together but only
meet later in life have a higher probability to fall in love than non-siblings.


There are two ways of
understanding the court’s decision that is based on all three points. The decision
may be based on a slippery slope
, meaning roughly: When we allow a morally questionable, but not
condemnable behaviour now, there is a high chance that it yields to clear
breaches of the law. For example, allowing brother and sister to live together
with their children in this case might establish
a bad example and motivate various kin to live their love.

But the slippery slope argument
cuts both ways: Forbidding the brother-sister love might yield future
amendments in legislation that are more than questionable from a moral point of
view – particularly because, as outlined above, a legislation consistent as
regards the aspect of protection from hereditary diseases has to forbid a lot
of relationships and thus get into conflict with the right to self


Another way of understanding the
courts decision is that it acknowledges the existence of moral emotions in the society that are opposed to inbreeding. In
general, such arguments are quite tricky, but in this case it raises
particularly the question as to what extend the positive law influences our moral
emotions. In France or Belgium, for example, incest is legal since the time of
Napoleon; the moral emotions opposing inbreeding much less pronounced than, for
example, in Germany a country that is despite France forerunner position in
laicism (i.e. the absence of both religious interference in government affairs
and government interference in religious affairs), is more secular than France.
Just recall Claude Chabrol’s movie La
Fleur du mal
in which the love between brother and sister plays a central role.

One might argue that the moral emotions
against inbreeding are the right ones as there are studies that suggest a kin
recognition ability that functions on part to enable incest avoidance between
close relatives – possibly to protect the gene pool. Firstly, the conclusions
drawn from these studies are more then doubtful: Though children raised
together during their first five years have inhibited sexual desire towards
each other (known as the Westermarck effect),
brother and sister that meet only later in live have an enhanced likelihood for
falling in love. Secondly, even if there was a natural aversion against
interbreeding, there do not follow any normative conclusions regarding our
legislation form this in a straightforward way.


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