On the Beginning of Human Life

Cambridge: Cambridge University Press, 1991.

Ford, p. 102ff.

Ford, p. 113.

Physics 192b21–23.

Metaphysics VII.

Aristotle, De Anima II, 1, 412a18–23.

See “Nature as Animating: The Soul in the Human Sciences”, The Thomist, 49, 4 (October, 1985), 612–648, or, more recently, The Modeling of Nature: Philosophy of Science and Philosophy of Nature in Synthesis, Washington, D.C., The Catholic University of America Press, 1996.

From a Realist Point of View. Essays on the Philosophy of Science, Washington, D.C.: University Press of America, 1979, p. 226.

192b21–23. Translated by Hardie R.P. , and Gaye R.K. , in The Basic Works of Aristotle, McKeon Richard , editor. New York: Random House, 1941.

Aristotle, De Anima II, 1, 412a 8–23, Metaphysics VII, 1041b6 and VIII, 1043a35; Physics II, 193a27–193b8. For Thomas Aquinas see the respective commentaries and Summa Theologica Q44 a 2 and Q46 a 1.

Summa Theologicae I, 90, 3 and 4.

Actually the phrase “moment of conception” is not clear. Conception includes fertilization and implantation because the word includes acceptance or reception of the conceptus. “The simple primitive insight expressed by conception is that of a female mammal holding on to the semen which in some mysterious way leads to the start of a new life and thereby enables her to bear offspring in her womb.” (Ford, P. 8) However, most persons using the phrase today are using it as synonymous with fertilization. Fertilization is also not occurring in a momentary fashion. When the head of the sperm touches the outer membranes of the ovum, the corona radiata, there is a potential that develops and prevents entry of other sperm into the zona pellucida. Over the next 20–24 hours the ovum forms another pronucleus with 23 chromosomes and finally the two sets of chromosomes line up and merge in syngamy. Thus, fertilization is a process requiring 20–24 hours. (Carlson, pp. 29–31, and Ford, pp. 102-1-8).

Carlson B.M. , Human Embryology and Developmental Biology. St. Louis: Mosby Year-Book, Inc. 1994, especially chapters 2, “Transport of Gametes and Fertilization”, and 3, “Cleavage and Implantation.”

For a summary of these teachings of Aristotle, see Ford, esp. pp. 25–42.

Ashley B. , “A Critique of the Theory of Delayed Hominization”, in An Ethical Evaluation of Fetal Experimentation: An Interdisciplinary Study, edited by McCarthy D.G. , and Moraczewski A.S. . St. Louis: Pope John XXIII Medical-Moral Research and Education Center, 1976, Appendix I, pp. 113–133, esp. p. 125.

May W.E. , “The Moral Status of the Embryo”, Linacre Quarterly, 59: 4 (November, 1992) pp. 76–83.

Lejeune J.J. , Testimony in the circuit court for Blount County, Tennessee, at Maryville, Equity Division, (Div I), 1989.

Irving D.N. , “Scientific and Philosophical Expertise: An Evaluation of the Arguments on ‘Personhood”’, Linacre Quarterly 60: 1 (February, 1993) pp. 18–46.

Irving, p. 26.

Sutton A. , “Ten Years After the Warnock Report: Is the Human Neo-Conceptus a Person?”, Linacre Quarterly 62: 2 (May 1995) pp. 63–74.

Sutton , p. 70

Apologeticus 9, 8, quoted in Williams G.H. , “Religious Residues and Presuppositions in the American Debate on Abortion,” in Theological Studies 31: 1 (March 1970) p. 25.

Ford , p. 110.

Ford , pp. xv.

This is the main thesis of Ford's book When Did I Begin? but it is the focus of pp. 91–101.

“Nature and Human Nature as the Norm in Medical Ethics” in Catholic Perspectives on Medical Morals, edited by Pellegrino E.D. , Langan J.P. , and Harvey J.C. Dordrecht: Kluwer Academic Publishers, 1989, pp. 23–53; and “Aquinas's Legacy on Individuation, Cogitation, and Hominization”, in Thomas Aquinas and His Legacy, editor Gallagher D. , Washington, D.C.: The Catholic University of America Press, 1994, pp. 173–193.

“Immediate Animation and Delayed Hominization”, Theological Studies 31: 1 (March 1970) pp. 76–105.

For a review of historical positions see Williams George H. , “Religious Residues and Presuppositions in the American Debate on Abortion”, Theological Studies 31: 1 (March 1970) pp. 10–75. A thorough review of Aquinas may be found in Stephen J. Heaney, “Aquinas and the Presence of the Human Rational Soul in the Early Embryo”, The Thomist 56: 1 (January, 1992) pp. 19–48; or see Wallace, “Aquinas's Legacy”, p. 193, n.26. All of the authors we have referred to invoke the teaching of Thomas Aquinas.

Ford , p. 49; Williams, p. 47.

Heaney , p. 23ff.

Ashley , 121–125; and Heaney. This is the main thesis of Heaney's article.

p. 20. These principles are based on Thomas Aquinas, Summa Theologicae I, 90, 3 and 4.

p. 79. Cf. Aquinas, Summa Theologica I, q. 118, a. 2, ad 2; Summa Contra Gentiles 2, 89.

Ford , p. 113

Ford , p. 118. These claims are supported by the following: C.R. Austin, ‘The Egg’ in Germ Cells and Fertilization, Book 1, Reproduction in Mammals, eds. Austin C.R. , & Short R.V , Cambridge University Press, 1982, pp. 52–4; A. McLaren, ‘The Embryo’ in Embryonic and Fetal Development, Book 2, Reproduction in Mammals. pp. 12–4. The four-cell stage is suggested for the expression of the human embryonic genome by P. R. Braude, V.N. Bolton, and M.H. Johnson in ‘The use of human pre-embryos for research’, in Human Embryo Research: Yes or No?, the CIBA Foundation, London: Tavistock Publications, 1986, p. 68.

Ford , p. 147.

Ford , p. 145.

Conception in the Human Female, London: Academic Press, 1980, 931–3. Cited in Ford, p. 133. These figures are determined by whether or not the chorionic membranes are shared by the twins.

p. 67.

Further research and evaluation are required, but it is interesting that scientific data points to a 50% loss of early embryos before implantation is completed. Most of these are from genetic errors. See Shannon and Wolter, p. 618–9; Allen C. Enders, “Implantation (Embryology)”, in Encyclopedia of Human Biology, Vol. 4. Editor-in-Chief R. Dulbecco. San Diego: Academic Press, Inc. 1991, p. 429–30; and Wilcox A.J. , Weinberg C.R. , O'Connor J.F. , Baird D.D. , Schlatterer J.P. , Canfield R.E. , Armstrong E.G. , and Nisula B.C. , “Incidence of Early Loss of Pregnancy”, The New England Journal of Medicine 319: 4 (July 1988) pp. 189–194.

Aristotle's Categories, la25–7. Translated by Edghill E.M. . In The Basic Works of Aristotle, McKeon R. , editor, New York: Random House, 1941.

“Nature and …Medical Ethics”, P. 29.

Aquinas: “Natural form…requires determinate quantity.” In physics, n. 1067, BAST, 529. Aristotle: “Distinct forms require distinct matter.” Physics 194b 8–10, Apostle tr. 29.