Hominisation is broadly understood as the process (and its implications) whereby a human being comes into existence. Three problematic aspects of the process can be specified: the biological, the medical/moral, and the theological. For the biologist, "hominisation (anthropogenesis) means the phylogenetic processes by which man has developed by continuous transformations from a presumed Primate group of the Tertiary era in his bodily characteristics and also in his psyche" (Overhage). The biologist recognizes, therefore, the close resemblance between man and the higher Primates, but also emphasizes that with the emergence of man there is a completely new type of organism, i.e., one endowed with speech, spiritual behavior, and the capacity to form a culture. Thus, although there are no unambiguous criteria for distinguishing man from lower animal organisms, and although substantial evidence for evolution from behavioral patterns common to all vertebrates clearly exists, all attempts to explain abstract thought by evolution remain unsuccessful. Discontinuity between animal and human behavior is acknowledged, and scientific research cannot yet give any definitive explanation of the evolutionary process leading to the appearance of man.
The term hominisation is also used in discussing the prenatal development of human beings, with obvious implications for the morality of abortion. Recent studies (Williams and Milhaven) have shown that Christian theology has varied considerably in its estimation of the moment when the fetus is endowed with a human soul (hominisation). The Church Fathers were divided on the issue, some holding that human life properly so-called was present at conception, while others decided upon hominisation at a later stage of fetal development. Thomas Aquinas's theory, defended today by Joseph Donceel both for its inherent worth and its appeal to the modern rejection of any soul-body dualism, supports delayed hominisation over immediate hominisation. According to Aquinas's hylomorphism, a substantial form—in this case a human soul—can exist only in matter developed sufficiently to receive it, i.e., only after several weeks of gestation. The more common Catholic teaching over at least the past two centuries, however, is that of immediate hominisation (Mangan). The absence of any qualitative difference in the human zygote from the time of conception to the time of birth is the central argument used for this position.
Theological reflection on hominisation deals especially with evolution and the place of man in the universe. Because any theological anthropology recognizes the radical difference between man and non-spiritual forms of life, it must hold for a definitive creative act in the evolutionary process whereby God brings man into being. Nor is this adequately conceived as an evolution of the human body and a special creative initiative by God in regard to the human soul. Since soul and body are not two autonomous entities but rather substantial principles of one individual being, "the spiritual soul which results from one direct creative act of God of necessity also signifies a transforming specification of the bodily component" (Rahner). This theory of moderate transformism seems to enjoy wide acceptance among Catholic theologians, especially insofar as it is compatible with biological theories of evolution, traditional teaching about the specific creation of man, and the eschatological dynamism whereby all existence tends toward spirit and spirit toward the one God (Teilhard de Chardin).
Bibliography: The March 1970 issue of Theological Studies (volume 31) is completely devoted to the problem of abortion and hominisation, and contains (among others) the articles by Williams, Donceel, Milhaven and Mangan referred to in the text of this article. p. overhage "Hominisation" in Sacramentum Mundi 2, 286–89. r. overman Evolution and the Christian Doctrine of Creation (Philadelphia 1967). k. rahner Hominisation, The Evolutionary Origin of Man as a Theological Problem (New York 1965). p. teilhard de chardin The Phenomenon of Man (New York 1959); The Future of Man (New York 1969).
[t. m. mcfadden]