
	  The Catholic doctrine of predestination does not exclude free
   will in any way.  Since God knows everything, He therefore knows
   everything that is going to happen to us.  We have free will, and
   are able to change what happens to us.  However, since God knows
   everything, He knows all the choices we will make "in advance" (God
   is not subject to time).  Too often arguments pit predestination
   against free will.  We believe in both.

That last sentence of Steve's is an important one to remember.

There are certain things in the Catholic religion that cannot be
completely comprehended by a human being.  Were this not the case, it
would be good evidence that the religion was man-made.

In the case of predestination, you have to reconcile two things that
would at first appear to be irreconcilable: the sovereignty of God's
will over all things, and man's free will in deciding his own fate.
Catholics believe in both!  But that doesn't mean that anyone has come
up with a pat reconciliation...