The separation of spirit and body in man has led to a growing tendency to consider the human body, not in accordance with the categories of its specific likeness to God, but rather on the basis of its similarity to all the other bodies present in the world of nature, bodies which man uses as raw material in his efforts to produce goods for consumption. But everyone can immediately realize what enormous dangers lurk behind the application of such criteria to man. When the human body, considered apart from spirit and thought, comes to be used as raw material in the same way that the bodies of animals are used—and this actually occurs for example in experimentation on embryos and fetuses— we will inevitably arrive at a dreadful ethical defeat.
Within a similar anthropological perspective, the human family is facing the challenge of a new Manichaeanism, in which body and spirit are put in radical opposition; the body does not receive life from the spirit, and the spirit does not give life to the body. Man thus ceases to live as a person and a subject. Regardless of all intentions and declarations to the contrary, he becomes merely an object. This neo-Manichaean culture has led, for example, to human sexuality being regarded more as a area for manipulation and exploitation than as the basis of that primordial wonder which led Adam on the morning of creation to exclaim before Eve: “This at last is bone of my bones and flesh of my flesh” (Gen 2:23). This same wonder is echoed in the words of the Song of Solomon: “You have ravished my heart, my sister, my bride, you have ravished my heart with a glance of your eyes” (Song 4:9). How far removed are some modern ideas from the profound understanding of masculinity and femininity found in Divine Revelation! Revelation leads us to discover in human sexuality a treasure proper to the person, who finds true fulfillment in the family but who can likewise express his profound calling in virginity and in celibacy for the sake of the Kingdom of God.
Modern rationalism does not tolerate mystery. It does not accept the mystery of man as male and female, nor is it willing to admit that the full truth about man has been revealed in Jesus Christ. In particular, it does not accept the “great mystery” proclaimed in the Letter to the Ephesians, but radically opposes it. It may well acknowledge, in the context of a vague deism, the possibility and even the need for a supreme or divine Being, but it firmly rejects the idea of a God who became man in order to save man. For rationalism it is unthinkable that God should be the Redeemer, much less that he should be “the Bridegroom”, the primordial and unique source of the human love between spouses. Rationalism provides a radically different way of looking at creation and the meaning of human existence. But once man begins to lose sight of a God who loves him, a God who calls man through Christ to live in him and with him, and once the family no longer has the possibility of sharing in the “great mystery”, what is left except the mere temporal dimension of life? Earthly life becomes nothing more than the scenario of a battle for existence, of a desperate search for gain, and financial gain before all else. – from Letter to Families (1994)