Al Leo and Christy: You are addressing a point which deserves to be discussed more in depth.
In my view, it is not the same to argue
assuming that there are not yet persons in the world,
as assuming that: there are already persons in the world.
We have to distinguish between two different questions:
Question 1:
How can we ascertain the time T at which the first human persons were created by God?
Question 2:
Suppose a Community after time T which is ruled by human persons according to the foundation of law. How can we ascertain whether a creature living in this Community deserves or not the status of person and therefore the fundamental right to life?
As argued in my Essay and preceding posts:
The answer to Question 1 is: Vestiges revealing sense of law.
The answer to Question 2 is: The living human body
It would be a fallacy to confuse the answers and
take the answer to Question 1 for the answer to Question 2,
or vice versa
the answer to Question 2 for the answer to Question 1.
The answer to Question 2 (The living human body) implies among other things that:
Any human embryo is a human person,
where:
- A cell entity which derives from the fusion of a human sperm and a human egg, and does not have DIANA anomalies is a human embryo.
- The term DIANA refers to anomalies that Directly Inhibit the Appearance of Neural Activity.
For further reading see my edited book Is this Cell a Human Being?.