Nature’s laws and natural law



George L. MurphyGeorge Murphy received his Ph.D. in physics from Johns Hopkins for work on general relativity in 1972. He taught at Westminster College (PA), The University of Western Australia and Luther College and did research for eleven years before entering Wartburg seminary. Ordained in 1983, he has served as a pastor in Lutheran and Episcopal congregations. His first article on theology and science was published in 1977 and he has since published six books and numerous articles and continues to speak and lead workshops in this area. His most recent book, Models of Atonement: Speaking about Salvation in a Scientific World (Lutheran University Press, 2013), discusses ways of understanding the saving work of Christ in an evolving world.

NATURE and Nature’s Laws lay hid in Night: God said, “Let Newton be!” and all was light.

Alexander Pope’s lines were intended as an epitaph for Isaac Newton.  Foremost in his mind were probably Newton’s three laws of motion and law of gravitation, principles that enabled Newton and his contemporaries to solve difficult problems of celestial mechanics and are still a basic part of a scientific education.  Today we would be more likely to call them “laws of science.”  

But I begin with “nature’s laws” because that sounds very much like “natural law.”  The latter term is more likely to be encountered in connection with ethics and theology than with the natural sciences.  But there are connections, and scientific knowledge and the way it’s developed over time are relevant for some of the ethical issues that need to be dealt with today, issues for which both nature’s laws and natural law come into play.  

Laws of science

Few working scientists today spend time arguing about the word “law” in reference to the rules, principles, or whatever term they wish, that they use in their work.  Equations can be written to express the content of the law of the lever, the first law of thermodynamics, Faraday’s laws of electrolysis, etc., and scientists needn’t debate the meaning of “law” to get on with the job. 

If you do care about broader philosophical issues, “law” in this context may raise questions.  The word suggests a mandate laid down by some ruler, and if you don’t believe that there is a cosmic ruler, what could that mean?

But for those who believe in a deity who created the world, it makes sense.  Pope had that idea in mind, and it’s expressed well in an eighteenth-century hymn which, after referring to the heavenly bodies, says,

Praise the Lord for he has spoken;
worlds his mighty voice obeyed;
laws which never shall be broken   
for their guidance he has made.

There’s a more serious problem than the term “law” though.  As science developed after Newton, it was found that some physical phenomena like electrodynamics couldn’t be described with Newtonian physics alone.  Even more serious is the fact Newton’s laws are only approximately true.  They’re fine for the situations that natural philosophers of the seventeenth century studied. But for speeds comparable with that of light, very strong gravitational fields, or the atomic and subatomic realms, they have to be replaced by the principles of relativity and quantum theory.  

That has humbled us a bit and made us less confident that our present “well established laws” are the last word. They have stood up to observational tests so far, but there are still unanswered questions. We can say (if only as a statement of faith) that there really are “true laws” to which our present physical laws approximate, but we don’t know what those true laws are.    

There is no “life force” that doesn’t obey the laws of physics which are, in principle, basic for living things.  But in practice, the phenomena that we call life can’t be derived from physics alone.  Living things are studied in their own way and have their own laws which can be understood with the aid of knowledge from the physical sciences.  

Life is inherently complex, and it isn’t surprising that the biological sciences developed from a stage of data collection to an understanding of basic principles more slowly than did physics.  The real understanding of genetics came with Mendel’s publication of his experiments in 1865, and that lay virtually unread for thirty-five years.  In 1865 Maxwell also published the basic laws of electrodynamics, which were a step toward Einstein’s special relativity.   

Laws of ethic 

Since ancient times people around the world have thought about and have passed on principles of what they have thought to be proper behavior for all people.  The collection of statements illustrating the Tao or “Way”, a Chinese term for a universal code of proper behavior, that C.S. Lewis included as an appendix in The Abolition of Man, provides a helpful overview.  

Reflections on such principles by Greek and Roman philosophers were important for early Christian teachers, who could use them to argue that Gentiles ought to know and follow the same moral principles that had been given to the people of Israel through Moses.  They came to be called “natural law” as a parallel with the “revealed law” from Sinai.  

St. Paul provided a basis for Christian appeals to the idea of a natural law.  Early in his letter to Roman Christians, 1:18 – 3:20, he argues that failure to obey God’s law is a universal problem, that “all have sinned and fall short of the glory of God,” before presenting the death and resurrection of Christ as God’s solution.  Making that argument to Jews was straightforward because he could point to the demands of torah, the law of Moses, and say that those who know that law aren’t measuring up to its demands. But what about Gentiles who didn’t know torah?  Paul’s answer was Romans 2:14-15.

When Gentiles, who do not possess the law, do instinctively what the law requires, these, though not having the law, are a law to themselves.  They show that what the law requires is written on their hearts, to which their own conscience also bears witness; and their conflicting thoughts will accuse or perhaps excuse them on the day when, according to my gospel, God, through Jesus Christ, will judge the secret thoughts of all.

It’s sometimes claimed that the law is written on people’s hearts, but Paul doesn’t say that here.  Instead, “what the law requires” (“the works of the law” is a literal translation) is written there.  The distinction needn’t delay us here.  We can say that these verses provide no basis for claiming the status of natural law for rules that have no parallel in torah

The rabbis counted 613 mitzvot (commandments) in the five books attributed to Moses, but Paul’s writings make it clear that he didn’t consider them all to be binding on Gentiles.  He is rather vehement about this, particularly with regard to circumcision, in Galatians.  Some mitzvot are ceremonial and some are parts of the civil code of ancient Israel. In view of Romans 13:8, we might surmise that Paul had in mind something like Jesus’ statement of the two greatest commandments in the law — to love God with your whole being and your neighbor as yourself (Mark 12:28-32).   

The natural law tradition was developed by the scholastic theologians of the Middle Ages, a process in which Thomas Aquinas, who made extensive, though critical, use of the writings of Aristotle, was particularly important.  Natural law continues to be important in Roman Catholic teaching and practice, and in varying degrees in the teaching of other Christian communions.

That was then, this is now

Like scientific laws, ethical principles can change as understanding of the world changes.  The particular issues we’ll look at briefly here are the taking of interest on loans and artificial contraception.

Note that this is from 1965, 3 years before Pope Paul VI’s encyclical reaffirming Roman Catholic opposition to artificial contraception.

Torah prohibited lending at interest to another Israelite, though it was allowed on loans to foreigners (Deuteronomy 23:19-20).  Philosophers such as Aristotle and Cicero condemned usury, taking interest on loans, and their criticisms were echoed by church fathers.  Aristotle argued that money is simply a medium of exchange, and has no other value. Unlike living things, it can’t give rise to more money, so interest on a loan was “unnatural”. As Aquinas put it, requiring interest on a monetary loan in addition to repayment of the loan would amount to asking that the borrower pay twice for the same thing. 

Lending on interest continued to be seen as sinful, though there were exceptions and work arounds, through the Reformation. But today, lending or borrowing on interest is commonplace and draws no condemnation from religious authorities. The idea that money is essentially sterile and can’t grow is simply false in the economies of developed nations.   

The understanding of what is “natural” has changed as knowledge of the world and the forms of human society have changed. The belief that some ethical standards for business should be maintained is widely held (though standards are too often ignored), and we have laws dealing with predatory lending and other unfair practices. There is a natural desire for justice in such matters, but we continue to learn what that means as the world changes.

Contraception, birth control, is not just an example of how things change. It’s connected with other important questions and continues to be controversial.

In the Bible’s first creation story, humans are commanded to “be fruitful and multiply, and fill the earth and subdue it” (Genesis 1:28). That’s not in the second account. There we have a longer text (Genesis 2:15-24) that begins with God saying, “It is not good that the man should be alone” and ends with “Therefore a man leaves his father and his mother and clings to his wife, and they become one flesh.”  Reproduction is part of God’s purpose in creating humans, but so is companionship and becoming “one flesh.”

Until recently, numerous offspring were needed to keep families in existence, as Psalms 127 and 128 suggest.  People were needed to work in the fields in a primarily agricultural economy, and diseases and other dangers always threatened the survival of children. My grandmother told my father, “When you grow up and have children, you can expect that at least one of them will die before it’s grown.” She knew what she was talking about — two earlier children had died, and my father grew up as an only child.

The only biblical reference to contraception is the story of Onan (Genesis 38:8-10). It’s likely though that his sin was more refusal to have a child who would be counted as his brother’s than the act itself.  In the Greek and Roman cultures in which Christianity developed, various substances were used for contraception, and some of these were in fact abortifacients. 

Contraceptive methods such as condoms or avoidance of intercourse at times of peak fertility are all somewhat uncertain, and that probably helped to keep birth control from being a really controversial issue in churches.  

Ideas about natural law were a common feature of discussions on this topic, and not with only Roman Catholics.  Here the natural law argument seems much clearer than with usury.  The purpose of sexual intercourse is babies, and engaging in intercourse in such a way that it’s impossible for that purpose to be fulfilled is — well, “unnatural.” 

Indeed, but intercourse is a cause of other things as well — physical pleasure, of course, but also perhaps the advantages of close personal relationship, mutual support, and family structures which improve the chances that offspring will grow to maturity and continue to propagate the species. If the purpose of human sexuality is not just babies but babies who can grow up in, and contribute, to a humane culture with genuine respect for others, then perhaps it isn’t necessary that every act of intercourse be potentially fruitful. 

As long as contraceptive measures were more or less hit and miss (no pun intended), these debates were to some extent academic. Changing attitudes toward sexuality and awareness of an increasing world population led to greater openness to birth control from churches. A Supreme Court decision of 1965, Griswold v. Connecticut, effectively legalized artificial contraception by striking down a law which prohibited the use of devices or medications for it. But the real breakthrough had come in 1960 when the Federal Drug Administration approved the first oral contraceptive for women.

In 1963, Pope John XXIII formed a commission to study birth control and related issues, and its membership was expanded under his successor Paul VI. In 1966 the commission finished its work and issued a statement that included the suggestion that the church approve of the use of artificial contraception. But two years later the Pope issued an encyclical which maintained the traditional rejection of such practices.

There were strong reactions to that declaration and significant objections from prominent figures in the Roman Catholic communion.  One statement by Cardinal Suenens of Belgium was significant in view of our theme here of scientific laws and natural laws. He questioned, “whether moral theology took sufficient account of scientific progress, which can help determine what is according to nature.  I beg you my brothers, let us avoid another Galileo affair.  One is enough for the Church.” 

It can be claimed that there are true laws of nature that describe the physical world as well as true natural laws to which all humans ought to conform in their action. But experience has shown that our understanding of both types of laws is, at any given time, only approximate and open to improvement.  Dogmatism about such matters should be avoided.



Leave A Reply