Page 129 - EFI-RAV ZILBERSTIN_VOL 8.EFI-RAV ZILBERSTIN_VOL 8.1A

Pg: 129 - 5-Front 21-10-31

this indicates that the child’s father is not the individual believed to
be the father, is based both on logic and on the statistical analysis of
test results, which indicate that in an overwhelming majority of cases
a child’s blood type matches that of one of the parents and only in a
5 tiny minority does it differ from that of the parents. It is possible that
they can be relied upon in this and the principle that we follow the
majority will apply here, for we only doubt the assertions that they
make on the basis of their own evaluations and medical knowledge
but they are believed to state facts as they see them. Similarly, Teshu-
vos Shem Aryeh (Even Ha’ezer 112) writes that a physician is believed
when he says that using a mirror he saw that a woman has a bleeding
wound in her uterus, because this is determined solely by looking and
requires no judgment. It is difficult to argue that something visible
is a matter of estimation and opinion, see the Chasam Sofer (Yoreh
De’ah 158, cited above). However the above notwithstanding, i.e. that
most children’s blood type is identical to that of their parents, in a
case where we find a child’s blood type differing from that of the par-
ents, this apparently indicates that this child is from the minority. We
therefore ought to conclude that blood testing proves nothing about
a child’s origin.

“However, after careful review it is clear that a blood test showing
that a child’s blood type differs from that of its parents raises doubt
about the child’s paternity. When we come across a child whose blood
type differs from that of its parents we are forced to say that in this
case the child is not one of the majority, for most children’s blood type
is identical to that of their parents. This undermines the assumption
that the child is indeed its father’s child, because that assumption is
based on the principle that most of a woman’s cohabitations are with
her husband but if the child’s blood differs from that of its parents
we are compelled to say that this case is not one of the majority, so
it can be argued that just as it is not one of the majority in regard
to blood type, perhaps it is an exception to the majority in regard
to most cohabitations being with the husband. Stated more clearly,
we have here one majority acting in opposition to another majority,
which places the child’s paternity under question.

Reliability of Medical Testing for Paternity 2 113