2/2
It makes just as much sense to assume God withholds ensoulment to fertilized eggs that have no genetic change of birth as it does to assume ensoulment automatically at conception. And if that were the case, what about the possibility that God withholds ensoulment to every fetus that will not mature to viabilty? or birth?

Damn we Catholics are good a declaring and clinking to certainty where a more circumspect, humbler, parsimonious, approach to moral pronouncements would be a lot wiser. 

I think that will not occur until every theologian and every seminarian has been trained theologically within the reference frame of history--not the "Theology of the Trinity," for example, but "The History of the Development of Trinitarian Theology."