I'm sorry, C.M.M.M. I looked at the thread quickly before work, and all I read was this:
Impiety does not necessarily entail a willful state of being.
I assumed you were going to make the typical 'infants can't desire baptism' argument.
My point is that the decree is speaking of people with the use of reason. Who can be impious or pious, other than those with the use of reason? There are no pious or impious 2 month olds and there are no pious lunatics. Neither can merit or demerit, since the have not the use of reason.
And even though, he taught baptism of desire (years before the Solemn Magisterium rendered it heretical), I believe that St. Thomas has some useful points to make on this issue. Please read article 7 and article 12 on
this page.