Here various approaches are at one in overlooking the created dimension of nature and in misunderstanding its integrity. For some, “nature” becomes reduced to raw material for human activity and for its power: thus nature needs to be profoundly transformed, and indeed overcome by freedom, inasmuch as it represents a limitation and denial of freedom. For others, it is in the untrammelled advancement of man’s power, or of his freedom, that economic, cultural, social and even moral values are established: nature would thus come to mean everything found in man and the world apart from freedom. In such an understanding, nature would include in the first place the human body, its make-up and its processes: against this physical datum would be opposed whatever is “constructed”, in other words “culture”, seen as the product and result of freedom. Human nature, understood in this way, could be reduced to and treated as a readily available biological or social material. This ultimately means making freedom selfdefining and a phenomenon creative of itself and its values. Indeed, when all is said and done man would not even have a nature; he would be his own personal life-project. Man would be nothing more than his own freedom!
In this context, objections of physicalism and naturalism have been levelled against the traditional conception of the natural law, which is accused of presenting as moral laws what are in themselves mere biological laws. Consequently, in too superficial a way, a permanent and unchanging character would be attributed to certain kinds of human behaviour, and, on the basis of this, an attempt would be made to formulate universally valid moral norms. According to certain theologians, this kind of “biologistic or naturalistic argumentation” would even be present in certain documents of the Church’s Magisterium, particularly those dealing with the area of sexual and conjugal ethics. It was, they maintain, on the basis of a naturalistic understanding of the sexual act that contraception, direct sterilization, autoeroticism, pre-marital sexual relations, homosexual relations and artificial insemination were condemned as morally unacceptable. In the opinion of these same theologians, a morally negative evaluation of such acts fails to take into adequate consideration both man’s character as a rational and free being and the cultural conditioning of all moral norms. In their view, man, as a rational being, not only can but actually must freely determine the meaning of his behaviour. This process of “determining the meaning” would obviously have to take into account the many limitations of the human being, as existing in a body and in history. Furthermore, it would have to take into consideration the behavioural models and the meanings which the latter acquire in any given culture. Above all, it would have to respect the fundamental commandment of love of God and neighbour. Still, they continue, God made man as a rationally free being; he left him “in the power of his own counsel” and he expects him to shape his life in a personal and rational way. Love of neighbour would mean above all and even exclusively respect for his freedom to make his own decisions. The workings of typically human behaviour, as well as the so-called “natural inclinations”, would establish at the most — so they say — a general orientation towards correct behaviour, but they cannot determine the moral assessment of individual human acts, so complex from the viewpoint of situations.
Faced with this theory, one has to consider carefully the correct relationship existing between freedom and human nature, and in particular the place of the human body in questions of natural law.
A freedom which claims to be absolute ends up treating the human body as a raw datum, devoid of any meaning and moral values until freedom has shaped it in accordance with its design. Consequently, human nature and the body appear as presuppositions or preambles, materially necessary for freedom to make its choice, yet extrinsic to the person, the subject and the human act. Their functions would not be able to constitute reference points for moral decisions, because the finalities of these inclinations would be merely “physical” goods, called by some “pre-moral”. To refer to them, in order to find in them rational indications with regard to the order of morality, would be to expose oneself to the accusation of physicalism or biologism. In this way of thinking, the tension between freedom and a nature conceived of in a reductive way is resolved by a division within man himself. — from Veritatis Splendor (1993)