Many today argue that human life is falsely considered an intrinsic good of human persons, if by “life” one means simple bodily existence. This reality, they argue, is an important one, since it is a necessary condition for all other goods. But in itself life, understood in this strict way, is only an instrumental good. A full life, a life of real quality, is good—so the argument goes—but this goodness is from other intrinsic goods of the person which build upon the foundation of mere existence.

However, the truth is that bodily life in itself is a basic human good, as the following discussion will make clear.¹⁴

One reason some think life is not an intrinsic good of persons is that they think life is common to all living things. In a sense this is true, of course, but in a deeper sense it is false. Biological life is different in humans, in other animals, and in plants. This is a matter not of speculation but of fact, which is established in works on human embryology, human physiology, and so on.

Although animals can perform many of the kinds of functions performed by plants, they perform their functions in a way proper to them. Animals assimilate food, grow, and reproduce, but they carry out these so-called vegetative functions in an animal way. To be able to do some of the things plants can do is not to be a plant; to be partly perfected by functions generically common to plants and animals is not to be partly a plant.

The same is true of humans. Human persons can do many of the things which other animals can do and many of the things plants can do. But this does not mean a human person is partly an animal or a plant. Even biologically, a human being is a specific kind of organism. To be one finite kind of thing, by definition, is not to be any other finite kind of thing. An individual of a certain kind is of that kind through and through. Human life, then, is properly human, for every aspect of it is specific to human persons (see S.t., 1. q. 18, aa. 1–2; q. 76, aa. 3–4). In reality there is no life in general; this is merely an abstract concept.

The proposition that life is only instrumentally good implies that the human person or some parts of the human person are one thing and a person’s living body is quite another thing. This implied position splits the person in two, and so it is called “dualism.”

The Christian doctrine of the resurrection points to the falsity of dualism.¹⁵ Resurrection life is bodily life. When Jesus was dead, he was not without divine life, but he did lack human, bodily life. Eternal life means much more than the good of human life, but the importance of bodily resurrection can only be grasped if one accepts the intrinsic goodness of human bodily life, and so its real necessity for ultimate completion in Jesus. Paul makes clear how important resurrection is (see 1 Cor 15.13–26). At the same time, Paul himself seems to have envisioned the possibility of disembodied existence (see Phil 1.20–24; 2 Cor 5.2–10). The Church teaches the immortality of the soul (see DS 1000/530, 1440/738). Therefore, one cannot say that the resurrection is important only because one could not conceive any manner of communing with God unless bodily life were given as a necessary condition. Rather, resurrection is so important because bodily life is an intrinsic good of human persons; their human fulfillment would be incomplete without it.

One aspect of the unity of Christians with Jesus is a real, bodily unity. The resurrection of Christians is to a radically new form of life, grounded in their unity with the risen Lord (see 1 Cor 15.20–49). As one shares natural life and death with Adam, one shares in the death and resurrection life of Jesus (see 1 Cor 15.20–23). “He who raised the Lord Jesus will raise us also with Jesus and bring us with you into his presence” (2 Cor 4.14).

Now, if one firmly rejects dualism and takes seriously the Christian’s bodily union with Jesus, then the sanctity of human bodily life here and now is clear. The great concern in the Christian tradition about the sources of life and sexual activity which touches upon life’s beginning also is obviously appropriate—see, for example, Paul’s argument against fornication (see 1 Cor 6.15–20). Moreover, the real effectiveness, not mere symbolic value, of the sacraments is clarified, for they are means of conferring and nourishing the resurrection life one shares with Jesus. However, if one is imbued with a dualistic view of the human person, these important matters are greatly obscured.

Rational reflection supports the truth faith teaches. First, the instrumental view of the good of human life implies dualism. As already explained, intrinsic human goods are not possessions of persons, but the fulfillment of their being. On the instrumental view of life, life is not part of the intrinsic good of persons. However, life certainly is not separable from the living body, as if it were a mere possession. Thus, on the instrumental view of the good of life, the living body will be one thing and the fulfilled person something else. Thus the instrumental view of the good of human life implies dualism.

Second, dualism is indefensible (see S.t., 1, q. 75, a. 4; q. 76, a. 1). Life is not merely one process among others, a process which can be distinguished from breathing, feeling, choosing, talking, and so on. The life of a person is indistinguishable from the person’s very reality. Life must pervade every part and activity of a person, or something of the person would be unreal. Moreover, one’s fulfillment is the completion of one’s given self. If the personal goods which constitute fulfillment were other than one’s given self, one could not fulfill oneself by acting.

If the dualist conception of the human person and the instrumentalist view of the good of bodily life are false, why do so many people think this way? The question is not easy to answer. Modern Western culture has developed a peculiar view of human persons, considering them to be incommunicable conscious subjects, encased in body objects which conceal them from, rather than communicate them to, one another.

In part, this peculiar view must be due to factors proper to modern Western culture—for example, the felt separation from nature experienced by persons who live in cities, work with inanimate objects, and deal constantly in artificial symbols. In part, however, sins against bodily life and sexuality lead to a distorted consciousness of one’s self. For example, one can sin more comfortably in killing the unborn if one can separate human life from the person; similarly, one can abuse sexuality for gratification with less unease if one thinks of one’s true self as the gratified consciousness and one’s sexuality as a lower form of life with its own dynamism.