CRITICISMS OF NATURAL LAW
1. Aquinas took it for granted that God created the world, for a purpose, but not
everyone would agree with this. Many modern thinkers, including the writers JeanPaul Sartre and Albert Camus, the philosopher Bertrand Russell and the scientist
Richard Dawkins, claim that the universe is ‘absurd’ or ‘gratuitous’; it does not have a
reason, it is a ‘brute fact’, it came about by chance and not because of any divine
purpose. This belief does not allow for a Natural law approach to ethics, because it
rejects the initial premise, or starting-point, of the whole system.
2. Even if humanity were created for a purpose, it is not self-evident what that purpose
is. How do we know what is natural? Should we judge it according to the natural
outworking of physical laws? E.g. death may be the natural result of illness. So, if
morality is based on a rational interpretation of nature, should we ever try to prolong
the life of someone who is seriously ill?
3. Ideas about what is and is not natural change between generations, and are
different in different cultures. It can sometimes be difficult to separate what is truly
natural from what is just culturally acceptable. E.g. it has been argued that in the
past it was unnatural for women to be doctors, and unnatural for people from
different races to marry, and natural for some people to work as slaves, but most
people no longer accept these views. Natural Law has frequently been cited in
condemnation of homosexuality, with the argument that it is unnatural for people of
the same gender to have a sexual relationship. However, recent suggestions that
sexuality could be genetically determined rather than a deliberate choice by the
individual raise the possibility of homosexuality being, in fact, natural as part of the
way in which some people are made. If we cannot agree upon a definition of
natural, then it becomes very difficult to appeal to nature in the making of moral
decisions.
4. Kai Nielsen (1988) argues against Aquinas’ belief in a basic human nature that is
present across all societies and cultures. He notes that anthropologists have
investigated practices in other cultures. At one time, members of the Inuit culture
killed members of their families who could not make it through the winter;
Scandinavians killed their elderly relatives to allow them into Valhalla. These differing
moral standards challenge the idea of a common natural law within all human
societies. NL obscures these basic moral differences.
5. Peter Vardy and Paul Grosch challenge the way Aquinas works from general
principles to lesser purposes. Aquinas maintains that as humans must preserve the
species, every discharge of semen should be associated with life generation. To use
the genitals in other ways is immoral. However, it isn’t necessary that every discharge
of semen should produce a new life to maintain the human species. Sexual acts
could be justified on account of the benefits to a couple’s relationship.
6. If the principles of Natural Law are strictly applied, some of the rules that result are
unacceptable to common sense. For example, human teeth include incisors, for
nibbling vegetables, and canines, for eating meat; by the principles of Natural Law,
this would mean that people ought to eat meat as well as veg, and that choosing to
be a vegetarian is wrong. Or, the principles of NL claim that sex is for the purpose of
procreation; therefore people who are infertile should not have sex with their
spouses.
7. The idea that humanity has a purpose is not without its problems as a concept. Is
there one universal purpose for the whole of humanity? Does this mean we should all
adopt the same forms of behaviour? NL suggests that every human adult should aim
to have children. However, this would mean that Mother Teresa was wrong to
become a nun and devote her life to the poor, and that Aquinas himself should not
have been a priest but should have been a husband and father instead. Aquinas
recognised this difficulty and answered it by saying that as long as humanity as a
whole fulfilled its purpose, by producing the next generation, it was acceptable for
some individuals to choose other ways of life. People today might answer this with
the comment that, in that case, it should be morally acceptable for some people to
adopt a homosexual lifestyle, as long as there are plenty of heterosexuals around as
well. In fact, it should be acceptable for any few individuals to choose to do the
‘unnatural’, whatever form it takes, as long as the majority follow NL; and this paves
the way for injustice, where some people consider themselves exempt from the rules
they wish to impose on others.
8. The idea that there is one common purpose which applies to all is not completely
supported by the Bible. In the Book of Jeremiah, e.g., God tells Jeremiah that his
purpose is to be a prophet, and that he had been selected for that role before birth.
Mary, in Luke’s Gospel, receives a message from Gabriel that she has been chosen
to be the mother of the Son of God. These examples, and others, show a Biblical
view that God can have different plans and purposes for different individuals, and
can set aside some people or groups of people (such as the Jews) for particular
tasks. If it is accepted that there might be different purposes for different people
(and Aquinas did accept this), then the application of NL becomes much more
difficult. E.g. it could be possible that God intends one woman to remain single and
devote her life and energies to medical research, while another might be intended
to be an excellent mother of many children; and how are people to know which
purpose applies to them, without direct access to the mind of God? Aquinas argued
that careful education of the conscience and emotional maturity was necessary in
order for people to discern what is right. Although this might be true, it introduces an
element of subjectivity, where people must use their own judgement and choose
from a range of possibilities rather than there being one answer which is ‘naturally’
obvious.
9. NL suggests that humanity has several different purposes to fulfil, rather than just one.
A follower of NL would accept that reproduction is not the only purpose of humanity
– otherwise there would be no difference between a person and any other animal,
or even plant – but would argue that people have other purposes too, such as to
love God, to learn, to contribute to society etc. However, if people have several
different purposes to fulfil, this could lead to dilemmas, where in order to fulfil one
purpose, another has to be sacrificed. An intelligent mother, e.g., might have to
choose between putting her brain to the uses for which it was intended and fulfilling
her intellectual potential, or following the purposes of her fertility and bearing and
raising more children.
What happens when specific moral injunctions conflict with the more general
principles that are given by moral law? E.g. Christ told his followers to turn the other
cheek when abused, whereas the natural law suggests that everyone has a right to
self-defence and self-preservation.
The NL approach does not give guidelines for judging what to do in such cases,
beyond advising the use of reason.
10. Are people in fact motivated by reason? It could be argued that Aquinas was too
optimistic in his view of human nature and reason. There is plenty of evidence on the
news every day to suggest that not everyone is naturally inclined towards the good,
and not everyone has the powers of reason which are necessary for the right
application of NL. Aquinas himself was a man of great intellect and wisdom, but
perhaps he rather generously assumed that the rest of us are like him, instead of
recognising his own superiority. Aquinas believed that when people act immorally,
they do so because they mistakenly think they are doing the right thing but this is not
always the case. Most of us have done something which we knew at the time to be
wrong, but we went ahead and did it anyway. Occasionally people set out to do
the worst thing they can think of, perhaps as a way of achieving notoriety.
11. Darwinian evolutionary theory has presented problems for NL. According to Darwin,
living things are motivated by a desire for survival, and evolutionary change occurs
through a process called natural selection, where the creatures most suited to their
environments survive and reproduce and the weakest fail and die. Not only does
Darwin’s theory suggest that humanity exists through chance rather than through the
deliberate will of God, but also it implies that humans naturally seek their own survival
and are fundamentally self-interested. This contrasts sharply with Aquinas’ view that
people are naturally inclined towards the good.
12. Some of Aquinas’ critics from within the church claim that he did not give enough
attention to the doctrine of the Fall, which is the traditional Christian idea that
humanity has become tainted and imperfect because of the sin of Adam and Eve.
Sin has made it impossible for people to have a reliable understanding of God’s
intentions for us, therefore we need the Bible and God’s revelation to us in order to
know what is right and cannot depend upon our own powers of reasoning to the
extent that Aquinas claimed. The great 20th century theologian Karl Barth held this
view, arguing that people should recognise and accept the revelation of God,
which is the only source of truth, rather than depending on fallible human reason.
13. NL has been accused of being based on a mistake known as the ‘naturalistic
fallacy’, outlined by G. E. Moore. One of the main points of Moore’s argument, taken
from the philosopher David Hume, was that it is not logically possible to look at facts
(e.g. moral law comes from God) and arrive at value judgements (e.g. we ought to
obey it); an ‘ought’ cannot be derived from an ‘is’. This has serious implications for
NL, which is based on the idea that our observation of what people are like gives a
clear indication of how people ought to behave. According to Aristotle and
Aquinas, our experience of human nature makes the ways in which we ought to
behave self-evident, but in Moore’s view this is a step of logic that cannot be
legitimately be made, it is not logically legitimate to take the fact of our human
nature and derive from it the values that determine human conduct.