Formally introduced by the 13th century philosopher Thomas Aquinas, Natural Moral Law (hereon NML) proposes that goodness can be achieved by discovering and acting upon what is natural. Everything has a purpose/telos, and by fulfilling this purpose, it is thought that goodness can be reached. Aquinas builds his argument upon the synderesis rule: “Good is to be done and pursued, evil is to be avoided”. Whilst the theory invariably has strengths, there are also issues and contradictions which must be assessed if we are to properly evaluate the validity of the theory.
Whilst Aquinas is accredited with having published NML, he was considerably influenced by his predecessors, particularly Aristotle. The role of these philosophers could be argued as being a strength of the theory. Living in the 4th Century BCE, Aristotle said that everything in the world had a “telos”, otherwise known as a Final Cause. It was when something achieved its purpose that Aristotle believed there to be goodness, and so by looking at something’s purpose, people can see what is natural for it to do. According to Aristotle, the ultimate purpose of man is Eudaimonia/Beatitude (reaching a perfect union with God); however, Whilst this may have been valid in the 4th century BCE, Aristotle’s words would not bode well with a secularist society and would consequently discourage people from following these laws. Aristotle defined nature as, “that which is equally valid everywhere… natural is unchanging and has the same power everywhere”, and this would later influence Aquinas in his hierarchy of Laws. Cicero (1st Century BCE) is another philosopher that is heavily tied up within NML; in fact he is often called ‘the father of NML’. In his book On the Republic, he wrote, “one eternal and unchanging law will be valid for all nations and all times”, further mirroring Aquinas’s Laws (Eternal Law, Divine Law, Natural Law and Human Law). The fact that people throughout history have accounted that there are laws to human nature adds greater validity to Aquinas’s words because there are people of other societies and religions that have come to similar conclusions. Even Plato, known as having opposite ideas to Aristotle, touched upon the idea of Natural Law in The Republic when he described, “a city which would be established according with nature”. The extent to which this acts as a strength is debatable because a large number of advocators does not necessarily signify truth. Whilst those that agree with the concept of Argumentum ad populum would claim that numbers equal truth, I would argue otherwise, using the example of of the world being flat — just because thousands believed that this was the case, it did not mean that they were correct.
Cicero and Aristotle were significant in the establishment of NML; however, perhaps the greatest influence was the Bible since Aquinas himself was heavily religious Christian monk who is known to have said in a poem, “we are all madly in love with the same God”. One can see substantial parallels between NML and the Bible, particularly in St. Paul’s Epistles to the Romans where it says, “When Gentiles, who do not possess the law, do instinctively what the law requires”. As with NML, it is implied that law is within human nature and that people have the same moral rules for themselves. “The creation of the world has been clearly perceived in the things that have been made”, (Romans 1:20) seems to have further influenced Aquinas. It seems that Aquinas interpreted that natural revelation refers to what God has allowed for man to understand naturally. Therefore, by understanding nature, one can understand God. It is inevitable that many Christians would observe this biblical influence as being a great strength on NMLs part since, in the eyes of many dogmatic Christians, the Bible is a reliable source to work with (especially since it is “the word of God”). As a secularist, however, I do not regard this as a strength and if anything, I would argue that it was a weakness. In NML, Aquinas does of course make the assumption that there is a God — he goes so far as to make one of his primary precepts worshipping God — however, 21st Century Western milieus are primarily secularist, and so one must question just how much truth a religious theory such as this holds nowadays. Some theologians may argue that a theory with such a biblical basis is able to offer practical benefits to society. Indeed, the American Philosopher, William James, said, “this sort of happiness is found nowhere but in religion”, and maintains that religion, even if false, can be the best path to follow. Within NML, Aquinas uses the Cardinal Virtues to distinguish between real and apparent goods and assist people in following the laws that God has set for us; these virtues — prudence, temperance, fortitude and justice — invariably offer positivity if individuals decide to adopt them. The three virtues of the Bible (faith, hope and charity) similarly promote care and compassion between people. The seven deadly vices additionally guide people, even non-Christians, in living a good life. According to Aquinas, “Vices should be uprooted before virtues are sown, according to Psalm 33:15: \”Turn away from evil, and do good,\” (Summa Theologica). If one avoids the vices and develops the virtues, they will ultimately always correctly use reason and keep to natural law. I do feel for this to be a reasonable strength of NML because it encourages more people to be selfless and kind, and thereby it can have a great practical effect on any society. However, I feel as though there is a contradiction in Aquinas’s reference to the importance of temperance since it is somewhat in contrast with the primary precept of survival — NML states that one should fight in self-defence instead of restraining themselves.
NML is an absolutist theory — in other words, it must be followed without question whatever the circumstances. Aquinas proposed the primary precepts, the primary precepts are the self-evident rules from which the dictates of reason logically flow, as a way of governing one’s morality. They are self-preservation, reproduction, education of children, living in society and worshipping God — the most important of these being survival. These precepts are universal and in his book, Summa Theologica, Aquinas says, “Natural law is the same for all… there is a single standard of truth… known by everyone.”. There are those that would argue for this to be a strength in Aquinas’s argument because it ensures that there is no ambiguity as to how man should react to any given situation. The fact that all people are aware of these fixed rules allows for their to be greater societal order and thereby has a practical effect in preventing political anarchy. This was described particularly well by Bossuet, an advocate for the absolutist rule of King Louis XIV who claimed that, “it is only attention and vigilance that can save us from surprises”, and that it could prevent social anarchy. I can see reason in these claims; after all, rules which are easily understood are more likely to be followed. The fact that the theory is deontological further develops this strength because each action is intrinsically good or bad in itself, which invariably makes it much simpler to follow. Additionally, the deontological element maintains that actions are non-consequential; individuals have no control over the outcomes, only their actions and intentions, and so it could be argued that this gives people more control over their morals. Others would question whether one can ever intrinsically judge an action? Surely one must also consider the consequences since ultimately this is the part that will have an effect.
There are those that have argued that absolutism is a negative thing since it offers no leeway; however, Aquinas’s secondary precepts challenge this weakness since they make the theory more flexible. The secondary precepts are specific rules, such as only having one spouse, which can be interpreted depending on the context of the situation and thereby make the theory more flexible. Aquinas himself said, ““It’s secondary precepts…though they are unalterable in the majority of cases…can nevertheless be changed on some particular and rare occasion.” (Summa Theologica). These dictates are achieved through a more complex process of reasoning. For example, reproduction is one of the primary precepts, and the sexual organs similarly have the purpose of reproduction. This means that it is wrong for one to use these organs in a way that does not create offspring. This is evident in the Bible when Oman is killed because he “spilled his seeds… knew the child would not be his” (Genesis 38:9). St. Paul recognised that it is not always possible to follow natural law and work towards goodness “since all have sinned and fallen short of the glory of God” (Romans 3:23). Humans will always fall short of God’s best for them because of The Fall and man’s violation of their perfect relationship with him, and therefore it is important that there is flexibility within natural law. One could consider for this to act in favour of NML; however, it also raises the question of whether this makes the theory relative instead of absolute. If laws can depend on situation, surely it is not as objective as is first thought?
NML has further been labelled as outdated and no longer applicable in the 21st Century. Aquinas developed NML in a pre-scientific age before Darwin’s theory of evolution was published. Evolution suggests that man is the result of chance and not of God and explains that man is interested in survival not because of natural law but because of evolved instinct. It further states that man is a self-interested animal which contradicts Aquinas’s claim that all people are naturally inclined towards the good. Aquinas was additionally developing his theory in a milieu that did not have to worry about IVF, cloning and euthanasia. I think that this weakness is significant; it is true that NML does not cover many of the moral dilemmas that we face today.
However, one must consider Bernard Hoose and Richard McCormick’s development of a more modern version of NML (proportionalism). This can be used as a strength in favour of NML because it applies Aquinas’s original theory to a modern society. Proportionalism works inside of the framework of NML but does not insist upon an absolutist approach, providing a greater good can be served by laying it aside. To a certain degree, this view does actually adhere to Aquinas’s original theory since he claimed that it would be acceptable for a starving man to steal a loaf of bread in order to prevent himself from dying of hunger. This action adheres to justice because it is fair that the man gets the right to exist — a greater good is served by allowing the man to live. I personally feel that relativist, situational moral laws are more equitable and so I feel for proportionalism to be a substantially more reasonable theory seeing as it takes into account the situation. Consequently, it can be used in response to moral issues which are not covered in the Bible, and Christians can know what God thinks to be right instead of facing confusion. Unlike traditional NML, proportionalism recognises the holistic nature of man and as a result it is more applicable to humankind, making it a strength. Aristotle himself believed that the body and mind were separate and not one psychophysical unit (“we are enclosed in the confinements of the body”); however, he fails to take account of this when developing NML. The needs of the body can interfere with those of the mind, and Sigmund Freud touched upon this in his hierarchy of human needs which states that humans find physiological aspects (e.g. food, water, breathing) the most important, and self-actualisation (e.g. morality), the least important. It is a strength of proportionalism that this is taken into account since it recognises that man’s morals are not always under his control. Some Christian theologians have further observed that humans cannot strive for moral perfection, only moral compromise because we live in a fallen world where we cannot achieve the perfection of God — as Moses said, “their hearts were hard”. Therefore, people’s morals must sometimes be compromised; for example, proportionalism will not allow for somebody to suffer simply in the cause of upholding natural law, and recognises that some moral evils must be permitted if we are to achieve the greater good. Even Pope Francis has spoken in favour of this idea when he said that contraception can be considered as “the lesser of two evils” when having to choose between using contraception and abortion, and his claims that all contraception should be “the subject of serious conscious discernment” suggest that it can sometimes be a viable choice. Even before proportionalism was put forward in 1993, the Catholic Church has occasionally been shown to make NML situational — for example, from 1960-1965 in The Congo, Pope Paul VI “permitted nuns to use contraceptives in case of rape”. There are Catholics whom would argue that this leeway that has been shown on behalf of both the Popes and proportionality creates a gaping hole in the logic of NML since it allows for the authoritarian moral codes of the Catholic Church to be rejected. Whilst I feel that the flexibility of proportionalism is positive, it does lead to confusion as to whether or not it is an absolutist theory; I think that the alterations made by Hoose and McCormick are drastic enough for one to say that it is a completely different theory. It gives too much freedom to decide what is proportionally good, and thereby takes away from its claims of objectivity — which is considered to be a strength because there are no moral or emotional factors involved and it does not depend upon how the person feels on the day. Some have proposed that proportionalism is instead a form of utilitarianism since it takes into account the outcome of an action rather than its intrinsic worth.
The flexibility of the secondary precepts is additionally developed through the idea of Casuistry, derived from the latin word for “case”. This literally means that the morality of an action should be judged on a case by case basis, using NML as a standard to judge against. This can thereby be considered a strength of the theory since it can occasionally take into account the difficulties involved with a particular situation. In the Roman Catholic church, this part of the theory is used to apply the universal principles of Natural Law to specific situations; it is always done in a logical way because most principles have logical consequences. For example, it is principally wrong to kill innocent people, and so it would be wrong to bomb civilian targets (e.g. Dresden in WW2). However, it is acceptable to kill in self defence because this agrees with the primary precept of survival. Aquinas maintains that it can be morally acceptable for innocent people to die, providing that this is not the aim of the action — this is not dissimilar to one of the options of Philippa Foot’s Trolley Problem. Therefore, this is a strength of NML because it allows for greater flexibility in the choices that an individual can make, and the extent to which a person can use their conscience and reason for their own measures. However, we again are faced with the question of whether this makes NML a relativist theory instead of an absolutist theory.
In some situations, there will be an intended outcome and another significant but unintended outcome. Another strength of Natural Law therefore is the principle of Double effect which allows for an individual to morally perform an action that will produce both good and bad results. This is providing that the action itself is good or indifferent; the good effect is the one that is intended; there are no other means of achieving this good effect, and the good effect is not produced by means of the evil effect. In 1949, Joseph Mangan further added that, “there be a proportionately grave reason for permitting the evil effect” (A historical analysis of the principle of double effect). This principle is able to cement Aquinas’s theory because it does not stray from the Aquinas’s ideas of interior and exterior actions — it is maintained that our intentions are more important that the consequences of our actions. Therefore, I feel that this is a moderate strength in support of the theory; however, on a large scale, I do not think that this is something that people should oblige by. Whilst bombing one hundred civilians could save one hundred and one civilians, I do not think that this would be morally acceptable and that it would be better to not perform the action at all. Aquinas sealed this issue in his claims that double effect does not condone unintended outcomes which have devastating effects. In light of this, I would say that this theory somewhat supports NML because it creates a stronger basis on which people can rely when following natural law, and is therefore helpful in encouraging people to practically adopt it.
NML maintains that both the intention and the action are important. This could be regarded as a strength because all judgement takes account of the motives and so one is never condemned for having unknowing performed an evil action (an apparent good). Aquinas states that a person can perform a good interior act but a bad exterior act, for example stealing money to help a friend in need, and whilst theft is a bad action in itself, the individual is not so harshly condemned. I do like the more compassionate element of NML and think that this strength should not be ignored. God wants our actions to be intrinsically good because this acts in accordance with man’s ultimate purpose and so God is glorified.
Aquinas maintained that human nature was essentially good and that man could never knowingly pursue evil; after all, humanity naturally wishes to achieve “be perfect as your heavenly father is perfect” (Matthew 5:48). Some could argue for this to a strength of the theory since Aquinas puts great faith in the actions of man; however, one could also argue that this is merely an ignorant claim which is not true. Aquinas said that there are such things called apparent goods which are actions not in the pursuit of happiness that do not fit with the perfect human ideal. The example that Aquinas uses in Summa Theologica is, “A fornicator seeks pleasure which involves him in moral guilt.”, and whilst this action is morally wrong, the person is doing it because of instinct and not reason and so it cannot be considered as a truly evil action. I must say that I agree strongly with Aquinas’s point; in my opinion, there is no such thing as an evil person or action because all actions have some sort of justification behind them, however strong or weak these may be — perhaps the best example is Adolf Hitler’s conduction of the Jewish Genocide from 1939-1945. Of course, his actions were wrong, but he thought for them to be right. Aquinas would say that Hitler’s choice of this apparent good is an error because it isn’t really good for us. One could have an error of reason if they believe something to be morally right which isn’t. To correctly distinguish between apparent and real goods is to use reason rightly, and Aquinas recognises that this is not always easy; indeed this was made evident when he said, “No evil can be desirable… it is sought indirectly, namely because it is the consequence of free will” (Summa Theologica). Whilst I personally feel for the idea of apparent goods to be correct, I am aware that there are people that do not, and if this is the case, I recognise that this strength is no longer regarded as very strong. Some have argued that there are actions which are simply not justifiable, for example the Stacey Rambold rape of his fourteen year old student. In the case of the Moors Murders, Ian Brady and Myra Hindley repeatedly denied their actions, and surely this is evidence that they knew that what they were doing is wrong. Therefore, Aquinas’s theory is shown to be false because people do recognise when they are performing a morally wrong action. I must however note that it is possible that these criminals thought for their actions to be right and the law to be wrong, which would explain why they tried to deny their actions.
NML has also been acclaimed for its universality — all men and women share a common purpose and so natural law is applicable to everybody. This is a strength and perhaps the greatest practical result of this is the exchangement of judgement between cultures. Having a standard against which all people can be judged, means that one society can involve themselves in another’s political affairs without the fear of disrespecting their country’s morals. For example, countries can rightfully say that events such as South African Apartheid and Pol Pot’s Cambodian Genocide are morally wrong. I must say that this, as a practical effect, is extremely important because without some sort of universal law, some milieus could conduct barbaric events without any consequences. However, I do not feel that these universal laws should be taken from NML; the general standard of morality can instead be set via the UN human rights council. The strength in itself is strong and I agree that it acts in support of the motion.
Aquinas said that our purpose was God-given and evidence for this can be found in the Bible when God created man imago dei, or “in his own image”. Christians would consider for this to be a strength on NML’s part because for them, the Bible is a reliable source from which conclusions can be drawn. However, the 21st Century Secularist Society must question whether beatitude is really the ultimate purpose for those that do not believe in a God. I am a secularist myself and would not consider for my ultimate purpose to be union with God, and surely I could not be working towards this final cause without knowing such. Therefore, I do not feel for this strength to be viable since it is no longer relevant in the modern, scientific age. I do however feel that Aquinas’s proposed purpose of good can be seen as a strength because it encourages people to act compassionately and kindly to their fellow man. Aquinas said that God’s purpose for us is to be good and so by following this, with help from reason to rationalise whether an action fulfills its purpose in nature, we can locate our purpose. Aquinas said this in terms of ‘potentiality’ and ‘actuality’, two things which Aristotle had claimed that all things had. Potentiality is the possibilities of change within an existing thing, e.g. an acorn has the possibility of becoming an oak tree; and actuality is what something actually is. Aquinas said that it was better for something to have more of its potentialities realised (so a fully grown oak tree is better than the acorn or a stunted tree; a healthy man is better than a sick, ignorant or vicious man). This fulfillment is an essence of goodness. In my opinion, this is a fairly weak strength because it unrightfully criticises some people of not being good. If the potential of a man includes being able to run, it would be unjust to say that a disabled individual is not good because they cannot walk. Aristotle is being somewhat elitist here and consequently takes the value from the lives of some people. Anything that does this cannot be considered to be a strength.
Aquinas’s use of the hierarchy of laws and the three norms could be argued as being a strength of NML since it demonstrates that his ideas are well thought-out and so arguably more reliable. The three norms are the three different constituents of NML: the discriminating norm, the binding norm (norma obligans), and the manifesting norm. The Discriminating Norm is human nature itself; the binding/obligatory Norm is the divine authority which imposes man with the obligation to live in accordance with his nature; and the Manifesting Norm is, in effect, reason, which determines the moral quality of actions performed by the discriminating form. Aquinas’s use of the three norms strengthens his theory since it allows for us to understand how our morals reflect our nature, and thereby increases our comprehension of the theory, making it easier to follow in practise. This strength does not stretch to a large extent because it only minorly helps us in understanding the theory, and still does not close all of the gaps in NML.
Critics have argued that there is no such thing as a “common purpose” which invariably leaves Aristotle’s argument in shreds. One such individual who has argued this is the Canadian Professor of Philosophy, Kai Nielsen. Nielsen challenges the primary precepts and maintains that humans do not have shared nature and preservations. He used the example of the Inuits who would kill their elderly so as to achieve Valhalla, an action that is considered immoral in much of the world. In my opinion this weakness is both strong and rational; however, Aquinas might have argued that these Scandinavian people were simply not using their reason correctly.
Existentialists, including Sartre, Nietzsche and Camus, would further see weakness in Aquinas’s fixed purpose since they would argue that people have no ultimate purpose. They would look towards the 1943 words of Sartre: “Life has no meaning a priori… It is up to you to give it a meaning, and value is nothing but the meaning that you choose.” (Being and Nothingness). If Sartre is correct then Aquinas’s argument deteriorates. Whilst I understand that existentialism has become popular in postmodern philosophy, and is something that I agree with to some degree, I do not think that it is able to disprove Aquinas’s argument. There is not enough logical evidence to say that either theory is correct and so I do not think that this theory either weakens or strengthens the validity of natural law.
Infamous atheist, Richard Dawkins, would again find weakness in the common purpose idea. Whilst Dawkins does propose that everybody has a common purpose, he does not think for this to be God-given, or indeed metaphysical at all. In his novel The Selfish Gene, he proposed that the only purpose of man is to pass on our genes to the next generation. Dawkins has said, “We are survival machines – robot vehicles blindly programmed to preserve the selfish molecules known as genes”. Since there is scientific evidence to back Dawkins’s claim, I do feel that it is an important weakness to consider — Aquinas was after all living in a pre-science age and so this is not something that he could have taken account of when developing his theory.
Some Christian critics have argued that Aquinas’s theory does not fit with Christianity because not all people have the same purpose. In 1 Corinthians 7:7 it says, “Each man has his own gift from God”, which implies that not all people are the same and that people have different jobs to do whilst on earth. Indeed, Mother Theresa did not comply with the primary precept of reproduction and remained celibate so as to help the people of the Indian slums. Despite telling people to “become one flesh” (Genesis 1:1), the Bible also teaches that people should remain celibate — “It is good for a man not to touch a woman” (1 Corinthians 7:1), which suggests that people all have different purposes from God. This would render Aquinas’s argument incorrect. Whilst I am not Christian, I feel that this is the strongest weakness that has so far been stated because Aquinas decided to base Natural Law from Christianity. The fact that the two contradicts suggests that his theory was not properly thought out, and could suggest that there are further flaws which he was trying to hide.
Other Christians have further argued that Aquinas’s argument contradicts the Christian principles of Agape. Joseph Fletcher, the founder of situation ethics, has claimed that this “legalistic approach” is wrong since it does not take account of Jesus’s most important teachings. NML says that you can kill somebody in self-defence; however, on the sermon on the mount, Jesus taught for people to “turn the other cheek”. Furthermore, sometimes the most loving thing to do will not follow the guidelines of NML. For example, euthanasia goes against the primary precept of survival, yet surely it is most loving to respect somebody’s request to die? Again, I feel that this argument is a significant weakness of the argument because it further illuminates the differences between NML and Christianity. I believe for the teachings of Jesus to be the most important rules that Christians can follow since they are supposedly from God himself. Therefore, Aquinas has neglected a huge part of Christianity in the theory, which significantly weakens its validity in the eyes of the religious.
A few Christians, such as Karl Barth (20th Century), have even claimed that natural law contradicts The Fall (Genesis 1:2). According to these Christians, we cannot use reason to the extent that Aquinas implied because we are living in a Fallen world where humans are tainted and imperfect as a result of the sins of Adam and Eve. Consequently, reason is not reliable enough to judge our morals, and instead people must use the Bible and revelations of God to help us decide on how we should act. Barth has said that people should recognise and accept the revelation of God as the only source of truth, instead of looking towards human reason. This point does not considerably weaken NML because it is a matter of opinion and interpretation whether or not reason can be used to know God. From my secularist perspective, God is the result of reason and so it is only fitting that we can use our reason to determine what he is and how he wishes for us to act. If anything, Aquinas does not rely on reason enough: people should use their own morals to distinguish between right and wrong.
Other critics, such as G.E. Moore, have used Naturalistic Fallacy to find weakness in NML. In his book Principia Ethica (1903) Moore argued that just because something is, it doesn’t mean that we ought; just because something is in our nature, it doesn’t mean that we have to do it. In Moore’s words, “moral obligation is heavenly”: a natural property does not necessarily lead to moral judgement. Nielsen further developed Naturalistic Fallacy when he said, “These statements can very well be true but no moral or normative conclusions follow from them”.
Another weakness that has been found in NML is the over-simplicity of it. In their book, The Puzzle of Ethics, Vardy and Grosch argue that Aquinas’s theory is un-holistic and only focuses on parts of human nature as opposed to it as a whole. For one, homosexuality is not considered by the primary precept of religion. The lesbian country pop artist Vicky Beeching claimed that her homosexuality was a part of her “God-wired design”, and so surely Aquinas should have taken account of this when developing his theory? Vardy and Grosch further took the example of the sexual organs which, they observed, were used for things other than just sexual relations. The fact that there are gaps in Aquinas’s theory suggest that he could not tailor it to meet the genuine requirements of human nature. People act so differently that I think it would be ludicrous to assign just one fixed nature to all: it simply is not logical. Therefore, this weakness is able to greatly reduce the reliability of NML.
Lastly, we must consider the question: is everything natural good? I think it would ludicrous to conclude that cancer, tsunamis and earthquakes were good. This query greatly weakens Aquinas’s theory because he assumes that everything in the world is good, and everything can achieve goodness by fulfilling its purpose. Stephen Fry used the specific example of eye-burrowing worms, whose whole existence depends upon nesting in the eyes of children and making them blind. In his words, “What sort of God would do this?”. An omnibenevolent God such as the one described in Christianity, and thereby NML, would surely not define goodness in such a way.
Whilst there is strength and logic in Aquinas’s argument, there are also weaknesses that are impossible to overlook. In my view, new scientific advancements and an increasingly secularist society do not allow for NML to any longer be a valid ethical theory, since these new-found weaknesses greatly outweigh the strengths that we have seen. One can never govern their morals on such strict guidelines. As Arthur Schopenhauer observed, “compassion is the basis of morality”.