Circumcision is nonreversible body modification that damages and
mutilates the male sexual organ.  It should thus be entirely
prohibited on babies who have no capability of consenting.  Would you
find it okay for parents to mutilate their babies in other ways?  How
about cutting a babies ears or fingers off, binding a babies feet to
keep them small, or splitting it's tongue?  How about cutting a baby's
penis off entirely?  Certainly all such practices damage the integrity
of the human body, and impair its function for its entire life.  You
would not find it okay to impose circumcision on an adult male, would
you?  Would you find it okay to cut an adult males fingers off?  Then
how can you find it okay to impose circumcision on a baby?