The question and its focus centre on the relationship of bodily fact to moral norm, as indicated but not fully explained in the doctrine of Humanae Vitae.
Two questions need an answer: what is a 'fact' and what is a 'norm'; and what vision of man, if any, will integrate these parts into a whole?
There now follows a brief presentation of the findings, Chapter by Chapter.
Part 1, consisting of Chapter 1, seeks to show that the denial that a fact can lead to a moral norm entailed a view of human nature as uniform.
An answer to this uniformity is the conclusion that man made in the image of God is a unity-in-diversity of body and soul.
Reason has to listen to nature: to what nature teaches all animals concerning mating340; and this is a part of what provides the origin of the natural law norm as promulgated by reason.
Nature teaches, however, in two ways: the first is by an unconscious, embodied expression of the eternal law in the bodily-personal datum of the cycle of infertility; and the second is the realisation, and its implications, that the embodied dimension of the eternal law is a 'datum' for our conscious participation in the eternal law.
A point of divergence is emerging between man as a type of animal and a theological anthropology: the bodily-personal nature of procreation is a reason for locating its significance in the mystery of God and not simply in its resemblance to the order of animal nature.
Reflection on the instantiation of divine ideas in the design of human being, leads to recognising that this is a foundational element in the person's possession of moral potential.
Part II, consisting of two chapters, is particularly concerned with the results of the literature surveys.
Chapter 2 returns to the theme of David Hume's Naturalistic Fallacy.
The first finding is that Hume's fallacy entails a fallacy: the fallacy of claiming that human nature is more uniform than unified, in that a moral response is not very different from a perception of colour or a reaction of our constitution to a stimuli.
The second finding is the following definition of the Naturalistic Fallacy: nothing is to be in the conclusion that was not in the premises.
The outcome of a two part discussion is that because the nature of man springs from the creative action of God, this nature is a normative fact and stands as a moral potential to a moral action; however, the transformation of this moral potential into a moral action is through the action of reason.
Chapter 3 was the result of another return to the literature.
The principal finding of this chapter is that dualism tends to operate along the fact-norm divide in two ways.
The first is that, if a particular version of evolutionary theory is treated as a fact, it destabilizes human nature and leads to the possibility that any form of behaviour can become morally normative.
This indicated the possibility of a negative effect of a fact on a norm.
The second type of dualism is where the body-soul unity is not completely thought through and so a variety of human facts appear somewhat dislocated from an integral vision of the person; and, conversely, they appeared to imply their position in a vision of the person, one in body and soul, from conception.
Seeing the possibility of this increased the tendency to think that a positive interrelationship of bodily fact and moral norm is established at creation in the normative fact: 'male and female he created them' (Gn 1: 27).
Part III consists of two chapters.
Chapter 4 begins with a recognition that a basic principle is at work in the dissertation: being is a unity-in-diversity; and we recognize that it is based on the fact of the Blessed Trinity and that it is applicable to the nature of man in two ways: God created man, male and female; and each man is one in body and soul.
Man is a reproduction of the Actus essendi of the Blessed Trinity.
Thus emerges a positive complexity to the 'fact' of human being.
Chapter 5 strove to show that, if action is a manifestation of being, then the inclination to procreation is as spiritual as it is physical.
We seek to show that an attitude of being open to the possibility of the gift of life is both inscribed in the psycho-physiological structure of the marital act and is at the same time an inseparable part of a spirituality of being open to the will of God.
The doctrine of Humanae Vitae is an articulation of our anthropological reality; however, this reality is intimately dependent on the light of the Blessed Trinity for its complete recognition.
This reveals that we are a complex, unitary, 'personal fact'.