Being” means existing as a thinking, feeling agent; we do not normally talk about rock beings or river beings. That’s why fertilized eggs are not human beings. You can call a fertilized human egg as opposed to a bovine one. You can say it has the potential, with a willful decision on the mother’s part, to BECOME a human being. But until it develops a nervous system, it’s less conscious than a cow or even a worm, and has no place among the sentient agents which we value as human beings .
"benjamin1973:
The two main criteria Catholics seem to use are: 1) potentiality
These quotes, or more specifically the sentiment behind them, seem to be a large part of the misunderstanding, here. Catholics don’t argue from “potentiality” – the possibility of being, but rather from identity, what something is. We’re talking about the essence of a thing, about a branch of philosophy called “ontology”. We’re not talking about characteristics of a thing: including a thing’s traits, abilities, potential futures, and location. I admit that I have a degree in science, not philosophy, so this is going to be tough for me since I lack exposure to the relevant philosophical arguments and paradigms.
To a non-Catholic, talking about the essence of a human sounds an awful lot like talking about a soul. Which makes sense, as the “essence” or fundamental principle of a human is called the soul by Catholics. However, one can still talk about the essence of humanity, and about individual identity, without resorting to religious vocabulary and intent.
What I want to try to convince you of is that there is something transcendentally metaphysical about personhood that is more than the mind or body.
Unique DNA, on its own, does not make a person. Examples of this include:
- Identical twins and the hypothetical clone (two persons, one DNA code)
- Choriocarcinoma or molar pregnancy (unique DNA vs mother/father, no body plan, a tumor, not a person)
- Human chimerism (a special kind of conjoined twin: two sets of human DNA in one complete human body, often without deformity; this was two persons at one point, but one person died in utero, and only one remains. Now, ask me “which one”, and I’ll tell you that I don’t know).
One body, on its own, does not make a person. Conjoined twins are an example of this: two persons, one body.
Changes in the physical component parts of the body do not make a “new person”. Individual atoms, molecules, cells, tissues, and even organs often change over completely, but identity stays the same despite the changes.
A person is not contingent upon their memory, personality, awareness, or other aspects of their mental status. A person with retrograde amnesia (forgets who they were before, think Jason Bourne) is still the same person. Persons with “multiple personality disorder” (now called disassociative identity disorder) are not multiple people. Becoming unaware through coma does not make a person not a person; I intend for this to be a different matter than brain death.