Sir, – Dr Don O'Leary (February 11th) implies I wrote in my letter of February 8th that there is a consensus philosophical position on how human personhood should be defined, a position that has no need of supporting scientific evidence.
On the contrary, in my letter I described the human embryo/foetus and its development along the biological continuum in clear scientific terms. I then described two different philosophical definitions of personhood – one based on functionalism and the other on essentialism.
I personally favour essentialism as the superior philosophical frame, at least partly because it harmonises better than functionalism with scientific knowledge of the embryo and its progression along the biological continuum. And I said this clearly in my letter.
Dr O’Leary correctly states that I claimed that functionalism leads to “the startling conclusion that the status of both the embryo and the new-born baby are the same in terms of personhood”. This “radical” claim, he says, needs to be evaluated in the light of neuroscience and psychology.
But this claim has been thoroughly evaluated in this manner by many, including no less an authority than Dr Peter Singer, the famous ethical philosopher. Dr Singer has proposed since 1993 that the human embryo and the new-born baby have the same non-person status. On the other hand I hold, using an essentialist argument, that both the embryo and the new-born baby are human persons.
The pro-choice side of the debate on abortion defines the personhood of the embryo/foetus through the lens of functionalism and ignores the implications this has for the personhood of the new-born baby. – Yours, etc,
WILLIAM REVILLE,
Emeritus Professor,
University College Cork.