Aquinas at our shoulder
Quentin de la Bédoyère on the power of natural law
4 July 2008

Every fortnight I have the stimulating pleasure of leading a group on philosophy, under the auspices of the University of the Third Age. Our range is wide but, over the years, we have returned time and again to questions of morality. Given the diversity of backgrounds - Catholic, Jewish, Muslim and agnostic _- you might think that we had so little in common that serious and probing debate would be pointless. On the contrary. Although we often agree to disagree on particular questions we share fundamental principles in common, and we are always ready to give reasons for the conclusions we defend.

This is what is known as the natural law in action.

The protagonist of natural law in the western tradition is Thomas Aquinas. Even the secular philosophers who write about the concept, and maintain their variations, have Aquinas on their shoulder. And behind him stands Aristotle.

The first principle is that practical reason obliges us to follow the good and avoid the evil. We may be wholly mistaken about what constitutes the good in a given instance, but that is what reason obliges us to follow. However we achieve our basic understanding of the good through our understanding of nature, because acting in accordance with nature ensures that we are directed at the right target: that is, we flourish.

A simple example is provided by the dog. The nature of the dog, among other things, is to be active, to give and receive affection, and to relate closely to human beings. (We might note here that some key characteristics of this nature have come about through evolving from the wild, ancestral, species.) If we treat a dog in accord with its nature, it flourishes. If not, not. In a recent column, I looked at how we could discover the role of fatherhood through looking at the needs of human nature. Human nature is qualitatively more complex because it is a fusion of animal nature and spiritual nature. That is, it involves elements such as intelligence, free will and moral responsibility. We often speak of two natures - the lower nature and the higher nature - but this is just a convenience for discussion because the two interpenetrate in ways we cannot completely understand.

Aquinas speaks of a hierarchy in our grasp of what human nature requires to flourish. There are major constituents such as justice, responsibility to neighbour, right to life and conscience and so forth. These are recognisable by all. But as we move down the hierarchy towards more detailed application of these major principles so there is greater and greater room for disagreement. This can come about because our understanding of human nature and circumstance inevitably varies at the more detailed level, and so we arrive at different conclusions. Nevertheless, the UN was able to proclaim an agreed code of human rights, and call it "universal". Such declarations implicitly stem from natural law.

More importantly, grasp of natural law can vary because of ill-will and bad habits. We know that it can also be distorted through culture. Decent, commonsense people (such as many in my group) broadly accept our current abortion laws; we live in an abortion culture, and those out of line are considered indoctrinated or eccentric. So, for such reasons, deliberate or indeliberate, we may be blinded to what natural law demands.

Can natural law change? Certainly our knowledge of it can. For instance, a mistaken understanding of embryological development, which science corrected in the 19th century, led to a change in the status of abortion. And perception can change. The deeper understanding of conscience which led Vatican II to accept the fundamental human right to free choice of religion was an unacknowledged reversal of a long-standing Church teaching.

Circumstances can change, too. The general proposition that cannibalism is always wrong might be questioned should a group find themselves abandoned in a remote area and without food after, say, an air crash in which one of the party had been killed. In America in the 1880s the average woman gave birth to about seven children. And this was necessary to maintain the population because child mortality meant that only two or three children would survive to procreate. Today such an average birthrate would lead over a few generations to an astronomical increase in population. Do the maths. Such examples remind us that we cannot invariably generalise about what is needed for humans to flourish.

So far my description has been couched in terms of unaided human reason. Consequently we can debate the application of morals in the public forum. And it does not follow that atheists can have no moral sense. In fact their attacks on religion are often made in moral terms. They may have difficulty in explaining the source of moral obligation, but that is not the same as lacking it. Christianity, through St Paul, describes it as a law written by God in men's hearts. And indeed we hold that the imperatives of the natural law fundamentally arise from the fact that God created our nature.

The Church goes further, declaring that she has a special competence to interpret the natural law with an understanding illuminated and enriched by Revelation. Undoubtedly the concept of what it means to flourish is marvellously extended when human nature is understood as elevated by redemption, and created for an eternal destiny. But there remains a need to demonstrate the link between natural law as open to reason and its deeper application. For example, while natural law can make a very strong case for monogamous marriage, it has a higher imperative derived from Christ's declaration that monogamous marriage was intended for the human race from the beginning. For the believer, but not the sceptic, the case is closed.

The need to demonstrate this link is particularly great when a moral teaching which allows of no exceptions is declared. Sadly there have been occasions where accepted doctrines have needed to be modified or abrogated. Moving beyond the limits of human reason, where Revelation gives no certain mandate, can be a hostage to fortune.

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