Jeannette, I find that explaining to parents, in lay terms, the diff between
breastmilk feeding and any other milk feeding that puts breastfeeding in the
'normal' realm is to tell them that breastfeeding is like eating a regular
meal, but feeding any other milk is like eating a Thanksgiving or Christmas
dinner.  I ask them how they feel after the holiday dinner?  Overfull,
indigestion from too rich, too much, indigestible food, sleepy from the
effects, etc.  When do they feel like eating again after that kind of meal?
 Would they want to eat that way on a regular basis?  Then I explain the
difference in digesting breastmilk or cow/soy proteins, etc, and the
difference in effects on infant.  You begin to see the dawning 'Aha!' light
in the parents eyes, and suddenly they feel much more comfortable with
frequent feedings (grazing) at the breast.

Kathe Catone