Here’s the context of the snippet from John Allen/Chicago Tribune. It confirms btw my contention that Donum Vitae did indeed decline to make an explicit philosophical assertion on the matter (which we discussed in the when does human life begin thread). Since no mention of a new explicit philosophical assertion is made, it appears the status quo stands, even if expressed in stronger language. It is noteworthy that the word “embryo” and not zygote is used as technically an embryo does not include the zygote stage. “Embryo” has not just a technical usage but a theological or common usage that IMO would confine it to individuals being nourished by their mothers, which would take place only after implantation, not fertilization (part of its etymological history includes the meaning “fruit of the womb”). This accords with my view that a human life properly speaking does not exist until implantation in the ordinary natural case. (i.e. theologically speaking, not according to the dictates of biological taxonomy which place btw humans in the same animal kingdom as rats, though we know theologically humans are midway between angels and animals)
en.wikipedia.org/wiki/Embryo
In humans, it is called an embryo from the moment of implantation until the end of the 8th week
[from the pdf in OP]
If Donum vitae, in order to avoid a statement of an explicitly philosophical nature, did not define the embryo as a person, it nonetheless did indicate that there is an intrinsic connection between the ontological dimension and the specific value of every human life. Although the presence of the spiritual soul cannot be observed experimentally, the conclusions of science regarding the human embryo give “a valuable indication for discerning by the use of reason a personal presence at the moment of the first appearance of a human life: how could a human individual not be a human person?”.8 Indeed, the reality of the human being for the entire span of life, both before and after birth, does not allow us to posit either a change in nature or a gradation in moral value, since it possesses full anthropological and ethical status. The human embryo has, therefore, from the very beginning, the dignity proper to a person.
And here’s the paragraph from DV to which DP alludes to above:
This Congregation is aware of the current debates concerning the beginning of human life, concerning the individuality of the human being and concerning the identity of the human person. The Congregation recalls the teachings found in the Declaration on Procured Abortion: “From the time that the ovum is fertilized, a new life is begun which is neither that of the father nor of the mother; it is rather the life of a new human being with his own growth. It would never be made human if it were not human already. To this perpetual evidence … modern genetic science brings valuable confirmation. It has demonstrated that, from the first instant, the programme is fixed as to what this living being will be: a man, this individual-man with his characteristic aspects already well determined. Right from fertilization is begun the adventure of a human life, and each of its great capacities requires time … to find its place and to be in a position to act”. (25) This teaching remains valid and is further confirmed, if confirmation were needed, by recent findings of human biological science which recognize that in the zygote* resulting from fertilization the biological identity of a new human individual is already constituted. Certainly no experimental datum can be in itself sufficient to bring us to the recognition of a spiritual soul; nevertheless, the conclusions of science regarding the human embryo provide a valuable indication for discerning by the use of reason a personal presence at the moment of this first appearance of a human life: how could a human individual not be a human person?
The Magisterium has not expressly committed itself to an affirmation of a philosophical nature, but it constantly reaffirms the moral condemnation of any kind of procured abortion. This teaching has not been changed and is unchangeable.(26)
vatican.va/roman_curia/congregations/cfaith/documents/rc_con_cfaith_doc_19870222_respect-for-human-life_en.html
It appears that DP similarly declines to get explicitly philosophical, i.e. “expressly commital” philosophical on this matter. The Church is not the guardian of philosophy. The church is the guardian only of divine revelation as such. The church may have authority to teach in matters outside the scope of divine revelation, but she is not herself the guardian per se of philosohical matters. So, IMO, on philosophical questions like this we should not give the magisterium too much weight just as we wouldn’t on questions of a geopolitical nature even though the magisterium here also has authority to give an opinion on capital punishment, just war, and so forth. Just war theory has evolved. Originally it had as a few as three conditions. In the Catechism it has a few more. Some have urged the Vatican to further evolve it in light of new geopolitical data. Philosophy likewise evolves and can evolve not only with new scientific data but also with new philosophical reflection. For example, whether one goes with the (neo)-Thomistic view of the soul or the Scotist (after Blessed John Duns Scotus) view of the soul may be relevant.