The Church in her wisdom, her history and the
presence of
the Holy Spirit takes it upon herself to judge the
validity of
marriages presented to her for judgment. If the
presence of
some obstacle--called an impediment--is judged to
have been
there at the time of a wedding ceremony, the Church
issues
an annulment. She judges that while there may have
been a
wedding ceremony there was no marriage in the eyes
of God.
A wedding does not a marriage make. The parties are
then
free to contract a valid marriage.