The question of when life begins is answered by science, not theology. It is not a Catholic “belief” any more than it is doctrine that the Earth circles the sun. And science is not at all ambivalent on the matter.The development of a human being begins with fertilization… (Langman’s Medical Embryology)
Although life is a continuous process, fertilization is a critical landmark because, under ordinary circumstances, a new, genetically distinct human organism is thereby formed.…(Human Embryology and Teratology)
*“Almost all higher animals start their lives from a single cell, the fertilized ovum (zygote)… The time of fertilization represents the starting point in the life history, or ontogeny, of the individual.” *(Patten’s Foundations of Embryology)
Ender
Love it.
Natural science senses. It looks, listens, touches, sees, hears, thinks. It discovers, interprets, and proposes what is revealed.
Theology also senses,
informed by other sciences. It observes, interprets, and proposes what is revealed in relation to God as the revealer.
The observations you cite above help inform theology. It’s not as if theology proposes anything that is not reason-able in regards to conception. The Church’s teaching on human life is not valid merely because theology makes the claim, it is valid because
it is so.
True that theology proposes things which cannot be physically seen, but are in the meta-physical realm.
Neither natural science or theology create their own reality. They discover objective reality. In Catholicism this truth is expressed by the repeated words of Christ in the Gospels:
“To see”, “to hear”, “you’ve heard that it was said”, "from the beginning…"etc…
A fundamental requirement of the Christian call is to be a good observer of what is revealed.
Both science and theology require common sense, or the ability to make true observations that can be commonly held.
(in other words, common sense is not self absorbed, or “relative” to my self alone.) My self is not the arbiter of reality, as in a vacuum separated from others. If what I sense is true, it is observable in common with others also. (although others might deny what they see).