interesting, this. He just said something different in the last few days.
It is an extremely rational and morally defensible position to hold that a human embryo in a test tube is NOT a person.
Such an embryo is human, but is not necessarily a human person.
Once such an embryo is returned to the womb and implants, that embryo is fully alive and developing and the law should protect such an embryo as if he/she was a person - we don’t know exactly when such an embryo attains personhood in God’s eyes so we err on the side of caution.
Conception is when human life begins. But when does human personhood begin? If we say at conception, then we have a conundrum with all the embryos in freezers - are these frozen persons? Do they stay suspended in ice until the end of the world or the freezer breaks?
I don’t think the questioner had any clue about what he was asking and the necessary nuance in Newt’s answer.
The moment of personhood is not an easy issue to be certain about.
Of course as a Catholic I err on the side of protecting human life in the womb - and I also want to halt the creation of embryos invitro precisely because of this abhorrent situation in which we have thousands of these frozen human beings who almost certainly don’t meet the definition of “person”.