See our websites!

"It is through conscience that human beings see and recognize the demands of the divine law. They are bound to follow their conscience faithfully in everything they do."
Religious Liberty, no 2.



Chapter I of The Disintegration of Natural Law Theory: Aquinas to Finnis


First published by BRILL of LEIDEN NEW YORK KÖLN 1998 pp.1 - 47
and reproduced here with the usual permissions.


That Aquinas's philosophy is taken as an inspiring starting-point for a modern theory of natural law may come as a surprise to anyone who has been brought up with the interpretation of Aquinas's theory, standard in legal positivist circles, as a prime example of the 'naturalistic fallacy': the mistaken belief that norms can be inferred from facts.

Legal positivists differ in their diagnosis of the underlying assumptions that are responsible for this mistake. Hans Kelsen thinks that it is brought about by the assumption that there is a 'will' immanent in nature. According to Kelsen, natural law theory is a specimen of 'animistic superstition' or of a belief in God's will as immanent in nature.(1) H.L.A. Hart, who rejects this view, claims that it is not the belief in God that is accountable for naturalistic fallacies, but the teleological conception of nature:

[...] on the teleological view, the events regularly befalling things are not thought of merely as occurring regularly, and the questions whether they do occur regularly and whether they should occur or whether it is good that they occur are not regarded as separate questions.(2)

These difference's notwithstanding, both authors agree that in Aquinas's theory the principles of natural law are simply inferred from the observance of certain regularities in nature. These inferences are thought to be of a rather unimaginative type: 'human beings do naturally seek company, therefore they should live sociably'.

On the basis of such an interpretation, Aquinas's theory is certainly not a promising starting-point for any contemporary legal theorist. Not only because of logical fallacies; not only because it is difficult nowadays to assume widespread consensus on the existence of God, but also because our concept of nature seems no longer adequate to play the role required. Nowadays, many people would recognise their own views in the opinion of J.S. Mill that nature is reckless, utterly indifferent to suffering, and incapable of setting a moral example:

In sober truth, nearly all the things which men are hanged and imprisoned for doing to one another, are nature's everyday performances.(3)

. If Aquinas is once again to be taken as a starting-point for a new theory of law and morals, his theory should not be interpreted as a mere attempt to infer norms from nature.

That is why Finnis's new theory of natural law is based on the re-interpretation of Aquinas by Germain Grisez. Grisez, trained as a logician who is well aware of the difference between is and ought- statements, attempts to show that Aquinas is not guilty of a naturalistic fallacy. It is his view that Aquinas never translated natural regularities into value-judgements. Instead, Grisez claims that Aquinas's theory contains a valuable and hitherto underestimated method for 'practical reasoning': the kind of deliberation required in order to arrive at sound conclusions about good and evil and the courses of action to be taken. It is on the basis of this interpretation of Aquinas, adopted and developed by Finnis, that Aquinas is allowed to play such an important role in Finnis's own proposal of a modern natural law theory.

The contemporary theory of natural law proposed by Finnis and Grisez will be discussed in the two final chapters of this book, but as far as their interpretation sheds some light on Aquinas, it is clear that their views will be discussed here as well. In fact, whatever the defects may be of contemporary natural law theory, their interpretation of Aquinas is certainly inspiring. It focuses on a number of issues that are commonly neglected in 'naturalistic' interpretations of Aquinas. On the other hand, I shall argue that the contemporary natural law theorists tend to overdo things. In their ambition to detect a theory of practical reasoning, they tend to underrate the natural foundations of Aquinas's theory. So whereas legal positivists see only nature and hardly any reason, Grisez and Finnis perceive only reason and no nature.

In this chapter I shall first try to assess the structure of Aquinas's philosophy of natural law by examining the relationship between practical reason and nature. In the next chapter, I shall pay attention to the question how Aquinas's theory of natural law can be translated into requirements for individual as well as collective decision-making.

1. Conflicting interpretations

The debate about the question whether Aquinas is guilty of a naturalistic fallacy or not focuses nearly entirely on the status of Aquinas's so-called 'first principle of natural law'.(4) Aquinas defines this principle as: 'Good is to be done and pursued, and evil avoided',(5) and adds that it should be regarded as a self-evident principle, from which all the other precepts of natural law are derived.(6)

At first sight, the status of this principle seems to be rather unambiguous. If someone tells us to avoid evil and to do good, we generally take that as a moral principle. In itself, this principle is of course too general to inform us on what is to be counted as good and evil. If we want to use the principle as a starting-point for the derivation of more specific precepts, we should have some more information. Since Aquinas's concept of reasoning is inspired by Aristotle's model of the syllogism, we might expect him to use the first principle as a major, to be accompanied by informative minors.

Major: ..........................Good should be done and pursued, and evil avoided.(7)
Minor: ...........................................................x is good, y is evil.
Conclusion:................................................... x should be done, y should be avoided.

And, indeed, if we look at the passage in which Aquinas introduces his first principle, it seems as if Aquinas proceeds to formulate these informative minors. Immediately after his formulation of the first principle, Aquinas points to man's natural inclinations: man naturally inclines to self-preservation, to procreation, to sociability and to truth about God. This combination of the first principle together with the enumeration of natural inclinations, gives rise to the interpretation that, according to Aquinas, we can only comply with the first principle of natural law by consulting our natural inclinations. Since we do have a natural tendency to live sociably, we should live sociably.

This kind of interpretation seems to match with Hart's formulation of teleological ethics: the observation of natural inclinations gives rise to a formulation of moral propositions. It can be argued, however, that precisely the first principle prevents Aquinas from falling into naturalistic traps. Norms are not derived from nature, but from the normative injunction, expressed in the major. Nature is not the foundation of morals, but only plays a role where it informs us about our natural inclinations. Aquinas seems to argue consistently from 'ought' to 'ought', whereas 'is'-statements play only an intermediary role.(8)

Finnis and Grisez, however, are not satisfied with this line of defense. They think that even this more modest role for nature is too large. Whether the whole theory is erected on a general 'ought' or not, in both cases nature would be decisive in informing our practical judgements on desirable courses of action. According to Finnis, that was not at all what Aquinas had in mind when he formulated the general first principle. Finnis points out that for Aquinas—as for Aristotle—, practical reasoning was meant to be 'practical all the way through', i.e. independent from theoretical investigation of nature.(9)

How then should we interpret Aquinas's first principle of natural law? According to the modern natural law theorists, we should not understand it as a moral principle at all.(10) We should take it as a formal principle, which governs practical reasoning. It should not be read as a normative injunction, but as a methodological guideline for reasoning on moral affairs.

The textual context, in which the first principle is introduced, supplies some evidence for this claim. Here, Aquinas repeatedly refers to the parallel between the way we reason about theoretical matters and the way we reason about practical affairs. To Aquinas, both theoretical and practical reason find their starting-point in first principles, which are self-evident.(11) The first principle of theoretical reason is—a reformulation of—the principle of non-contradiction: 'There is no affirming and denying the same simultaneously'.(12) It is a basic guideline for proper reasoning concerning nature. The first self-evident principle of practical reason is the principle that good should be done and evil avoided. It is a self-evident guideline for proper reasoning on moral matters.

Since Thomas repeatedly draws this parallel between the two kinds of reasoning, it is indeed plausible to argue, as Grisez does, that the two self-evident principles have the same methodological status, which implies that:

Just as the principle of contradiction is operative even in false judgments, so the first principle of practical reason is operative in wrong evaluations and decisions.(13)

On the basis of the analogy with theoretical reason, Grisez and Finnis argue that the first principles of theoretical and practical reason alike have the function to direct the process of reasoning. Without these principles, reasoning would be chaotic.

This, however, does not imply that those who follow these guide­lines, necessarily arrive at truths, or—in the practical domain—at morally good actions. The first principle, understood as a formal principle, is a sine qua non for all reasoning about moral matters, but does not guarantee that this reasoning is sound, or that it gives rise to desirable and morally defensible lines of action. The principle merely expresses the fact that practical reason, unlike theoretical reason, is 'active'; it seeks to realise a certain end. As such it is a necessary condition for sound practical reasoning, but not a sufficient one.

The dispute whether the first principle of natural law is formal or moral appears to be less innocent than it seems at first sight. If we take the first principle as a general, moral injunction, which is further specified in the natural inclinations, Aquinas can be interpreted as a philosopher who regards moral rules as the outcome of inferences from natural inclinations. But if we interpret the first principle as a methodological rule, Aquinas's theory can be regarded as a theory of practical reasoning, which rests on the presupposition that man is to some extent free to deliberate on his particular conception of the good.

2. Exemplar of divine wisdom

In order to gain a clearer view on these matters, I think we should abandon the somewhat technical discussion on the first principle, and widen the scope of our inquiry. What exactly is the status of natural law and its relationship to that other important concept in Aquinas's writings: the eternal law? I think that once we succeed in answering these questions, we might be able to shed some light on the discussion concerning the first principle.

Natural law is defined by Aquinas as the participation (participatio) of rational creatures in the eternal law.(14) Natural law is 'the light of natural reason by which we discern what is good and what evil', or 'the impression of divine light upon us'.(15) We should, therefore, understand natural law not as 'law' in the ordinary contemporary sense of the word, but as an epistemological gateway, by means of which rational beings have access to the eternal law.(16) This raises the question what exactly the subject-matter is to which we have access by means of natural law. What does Aquinas understand by 'eternal law'? According to Aquinas:

[...] the Eternal Law is nothing other than the exemplar of divine wisdom as directing the motions and acts of everything.(17)

What then is meant by 'exemplar'? Aquinas explains his view by means of a metaphor. He writes that we can compare the eternal law God has in mind with the exemplar an artist has in mind when he sets out to produce a work of art. In fact, the eternal law as the guiding idea for God's creation is elucidated by a whole series of terms:

And so, as being the principle through which the universe is created, divine wisdom means art [ars], or exemplar [exemplar], or idea [idea], and likewise it also means law [ratio], as moving all things to their due ends.(18)

In order to define the eternal law, a whole set of concepts is clustered here. How are we to understand this cluster as elucidations of the lex aeterna In view of the emphasis of God's role as Artificer, I think we should take the metaphor of art more seriously than most interpreters tend to do. If we want to gain a proper understanding of eternal law, it seems we should inquire into the precise meaning of exemplar and to form an idea of the role the concept played in the medieval conception of art.

If one considers the sculptures and paintings of the Pre-Giotto period, it is tempting to think that for a medieval artist an exemplar was no more than a conventional pattern to be copied. If the medieval artist was asked to portray a particular bishop, he did not try to represent this particular individual bishop, but drew a conventional figure, recognisable as a bishop by his attributes, crozier and mitre.(19)

But if we understand exemplar in this way we cannot understand why Thomas equates eternal law with the exemplars God has in mind. If God created the universe on the basis of isolated stereotypes, individual creatures would be mere copies of those stereotypes. On the basis of such a view it might be understandable that Aquinas equates exemplar with ars and idea, but we cannot understand why these terms are further equated with lex and ratio, directing things to their due ends. If people already resemble the stereotypes God has in mind, why would there be need for a law to direct them? Or, again in the words of Mill:

If the natural course of things were perfectly right and satisfactory, to act at all would be a gratuitous meddling, which as it could not make things better, must make them worse.(20)

However, this was not the only way exemplar was used in medieval art. Although it is true that there were certain well-defined conventions to be followed, medieval art cannot be seen as a mere repetition of stereotypes. It could not be like that, because according to medieval standards all art had to fulfil a definite function. A work of art was only considered to be successful if it was judged to be suitable for its intended purpose. In order to judge artistic works on the basis of this criterion, one had to consider the work of art as a whole. The question then is not whether all the isolated elements of a painting (the Madonna, the bishop, or the angel Gabriel) faithfully represent the conventional images. Rather, the question is whether the painting as such is suitable for its purpose (for instance, as an altarpiece).

Apart from the criterion of suitability, a work of art had to meet the requirement of proportion. According to Umberto Eco, proportion is the most important criterion according to which works of arts were judged.(21) The elements should be represented in a harmonious whole. Like the criterion of suitability, this criterion can, of course, only be applied to a work of art as a whole. It seems then that the exemplar Aquinas has in mind, refers, not to an isolated pattern to be copied, but to the idea of a work of art as a harmonious and proportionate whole, which is suitable to the end it is meant to serve. The term exemplar refers to order, not to a particular element. In Eco's words:

Order is not so much a model to be copied as a compulsion that must be satisfied.(22)

If the exemplar which human artists have in mind is considered as such a 'compulsion' for order, this must be all the more the case where Aquinas speaks about eternal law as the exemplar in the mind of God. The exemplar in both man-made works and in God's creation might be thought of as something which

[...] presides over its construction and regulates it in a law-governed way.(23)

Both God and the human artist have an overall plan in mind for a harmonious whole directed to a specific purpose or end.

If we understand exemplar in this sense, it is clear why Aquinas clusters notions like idea and exemplar with those of ratio and lex. These are not different things. The exemplar God has in mind directs the way the world is and should be. In short, the world is created in such a way that it is best fitted to these ends. It is because of the directive power of the exemplar that it can properly be called 'law'. And, in accordance with the above-mentioned aesthetical criteria, Aquinas remarks that law (lex) is a rule (regula) and measure (mensura). It is a rule, since it directs the elements to their appropriate ends, a measure, in so far as it makes sure that the elements stand to one another in due proportion.(24)

'Law', like 'exemplar', refers to an overall plan for the construction and regulation of a work of art (or, in God's case: the created universe). In the words of the famous writer on medieval psychology and moral theory Odon Lottin:

[...] la loi, avant d'être un principe d'obligation, est un principe d'ordre, règle de vie, norme de moralite.(25)

The eternal law is an ordering principle regulating God's creation, rather than a set of coercive precepts.

In aesthetics there is a term for such an ordering principle: 'style'. I think that the term 'style' is more appropriate to clarify Aquinas's concept of 'eternal law' than the term 'law'.(26) It does justice to Aquinas's conception of God as Artificer, and it excludes all kinds of misunderstandings, provoked by the term 'law'.

As we shall see in the chapters on Suarez, one such misunderstanding is to think that God Himself is obliged to obey the eternal law. Suarez thought that the concept of eternal law implied a serious blasphemy. The mere assumption that God would have been governed by a 'law', would entail the view that He was not free, omnipotent and sovereign, but that He was and is bound to obey some precepts, that are not of His own making.

The term 'style' prevents such a misunderstanding. It is true that God is 'bound' to it, just as an artist who decides to paint in an impressionist style can be said to be 'bound' to a certain degree of consistency and cannot suddenly revert to classicism in one and the same picture. But it does not imply that God would not have been free in His choice of style. The adoption of a style does not curb His sovereignty. On the contrary, style as an ordering principle is the sine qua non for creativity. It gives a general direction to the artistic process, and provides for a certain amount of unity and coherence within the artistic product. It is on the basis of these qualities that William James remarks that:

Aesthetic union [...] is very analogous to teleological union. Things tell a story. Their parts hang together so as to work out a climax.(27)

If we understand eternal law as divine style, it is clear why Aquinas could view the world as a unified, ordered whole. He conceived it as the expression of God's—self-imposed—style.

3.The divine style applied

But there are other advantages of the term 'style' as well. The most important one is that it clarifies the various ways in which created beings 'participate' in the eternal law. At first sight, it seems to be Aquinas's view that only rational beings can participate in the eternal law. According to Aquinas 'law is something that belongs to reason'.(28) Usually this view is taken in the ordinary sense that a subject has to know and understand the law in order to comply with the law.

But this interpretation raises some difficulties. According to Aquinas, irrational beings are also bound by the eternal law: '[...] Even non-rational creatures share in the Eternal Reason in their own way'.(29) They share in the eternal law by 'inward moving principles'. Apparently law is not strictly connected to rationality.

As we shall see, subsequent natural law theorists were troubled by this inconsistency. If law can only direct rational beings, how can we say that animals are bound by the eternal law as well? We can do that only by making the most of Aquinas's assertion that animals are subject to eternal law per similitudinem, as a figure of speech.

However, if we interpret eternal law as style, it is easier to understand what Aquinas had in mind. He regarded God's creation as an artistic product. As such, all creatures share in the eternal law in the sense that they are the - visual - expressions of the divine style, in just the same way as we might say that Monet's waterlilies are an expression of 'impressionism'. In this sense, both rational and irrational beings are an expression of the divine style.

But rational creatures participate in the divine style in an additional sense as well. Being endowed with reason, they can recognise the divine style in themselves and in other creatures and they can—and therefore they must adopt that style in the regulation of their own affairs. That is why Aquinas writes that rational beings 'join in and make their own the Eternal Reason through which they have their natural aptitudes for their due activity and purpose'.(30) 'Natural law' is indeed nothing other than a name for the rational participation in the eternal law. It expresses the possibility for rational beings to apply the divine style to their own dealings.

Whereas visual expressions of the divine style, in irrational beings are merely the expression of the divine style, rational beings are both expression of that style, as well as capable of adopting that style to their own affairs. This is why Aquinas writes:

Taken as a rule and measure, law can be present in two manners, first, and this is proper to the reason, as in the ruling and measuring principle, and in this manner it is in the reason alone; second, as in the subject ruled and measured, and in this manner law is present wherever it communicates a tendency to something, which tendency can be called derivatively, though not essentially, a 'law'.(31)

The two meanings of the word 'law' referred to here are at the root of our later distinction between a normative law and a descriptive law (as in 'laws of physics'). It is only by means of the analogy with aesthetics, by understanding 'law' as 'style', that we are able to see why these meanings are not logically distinct in Aquinas's writings.

Law in the descriptive sense, refers to 'tendencies' and qualities which are inherent in God's stylistic expressions. Normative laws, on the other hand, are the result of our own rational application of the divine style to human affairs.

It is important to note that rationality is indeed required in order to adopt that style. We are not expected merely to copy God's artefacts. To adopt a style is more than the repetition of stereotypes. Conventional examples may constitute a certain style—and there is certainly no style without such examples—but style is more than the sum-total of stereotypes. Why? Because a style does not contain precise directions in order to perform specific actions. An artistic style is not to be seen as a recipe on 'how to paint a portrait'. The term 'style' rather denotes a general way of making or doing things. In fact, 'style' is better fitted to express the kind of rationality required to 'partake in the eternal law' than 'law', for it shows that rational beings are expected to look beyond the examples and conventions. Just as a good painter does not merely copy Monet's waterlilies, but can adopt that style in painting a modern industrial landscape, a rational being is required to do more than doggedly follow God's precepts.

If we understand 'natural law' as the adoption of the divine style, we can also understand why natural law does not only prohibit us to commit evil, but also enjoins us to pursue and to do good. Many interpreters have drawn attention to the fact that Aquinas did not merely think of natural law as a set of prohibitions, but also of counsels.(32) Nowadays, we might be inclined to regard that as a correct representation of what any legal system is about. But as I shall show in III. 1, law's function as a source of actions was not always recognised. The term 'style' is illuminating because it reveals how both counsels and precepts hang together. For instance, the stylistic requirement of unity of time, place and action, which any successful classicist playwright had to meet, was not merely a constraint; it also opened a vast array of possibilities that would otherwise have remained unexplored. Style can be a source of creativity, in the same way that law can be a source of actions, associations and arrangements which would have been impossible without law.

So the term 'style' enables us to understand why Aquinas's concept of law comprises so many elements. It makes clear why he links law with rationality (the understanding and adoption of a style); why he nevertheless allowed irrational beings to be part of eternal law (as expressions); and finally why he thought of law as comprising both precepts and counsels.

But the analogy with art not only clarifies why so many notions are included.-, it also reveals why a certain topic is excluded from Aquinas's discussion on law. The topic which is excluded is the question to what extent rational beings are obliged to follow the natural law. Aquinas does not explicitly address the problem of obligation, when speaking about natural law. As we shall see, this 'omission' would ultimately prove fatal for any subsequent theory of natural law. The problem that haunts Suarez's analysis of natural law is that natural law only seems to indicate good and evil but does not oblige us to do good and to avoid evil.

The interpretation of etrernal law as divine style clarifies why Aquinas did not differentiate between these two functions. Natural law is not a set of moral rules, precepts and prohibitions. It denotes the capacity of human beings to adopt a style .The question is therefore not to what extent we are obliged to follow precepts, but to what extent we are obliged to adopt God's style. As to this latter question, there seems to be no problem involved. Aquinas thought that since our rationality is an impression of the divine light, we have no other alternative than to adopt His style. There is no variety of styles between which we can choose.

That does not mean that we cannot go wrong in the adoption of that style. Just as there are a lot of bad impressionist painters, there are a lot of people who inadequately adopt the divine style to their own doings. But that does not imply that we need an additional source of obligation for the fact that we should adopt the style. We cannot do otherwise. The problem of obligation, therefore, only surfaces when natural law is regarded as a set of precepts. Then, of course, promulgation of those precepts does not entail an obligation to follow them. But if we take natural law as referring to the possibility to adopt the only available style, there is no need to argue that we are obliged to adopt that style.

4.The role of nature

Once we understand the eternal law as a divine style, and natural law as the capacity of rational beings to adopt that style, we are able to resolve the debate whether the first principle of natural law is moral or formal. If we regard the first principle as a general stylistic requirement, Grisez seems to be right. The first principle is indeed not a general recipe or precept. It does not exhort us to paint only portraits. Nor is it purely 'formal', as Grisez maintains. It does not merely give us a guideline such as 'make always preparatory sketches'. In fact, the analogy with style reveals that the discussion between 'moral and 'formal' rests on a misunderstanding on what methodology is about. If we share the view of some philosophers of science that it is possible to detect various styles of scientific reasoning, (33) we might say that methodological rules and guidelines are constitutive of such a style. These rules do not decide which theories are 'true', but they serve as criteria according to which the question can be decided which theories can be true and which are not. In this sense, Grisez's assumption that the first principle is neutral and 'pre-moral' is exaggerated. Style and substance cannot be separated. The principle that good should be pursued and done and evil avoided, does not specify which particular act is morally praiseworthy, but it certainly asserts that some actions (pursuing evil) can never count as morally good acts. The first principle is indeed methodological, but as such it serves as a general evaluative criterion as well.

We have seen that the debate concerning the first principle entails a debate concerning the role of nature. If we take it as a moral principle, nature provides the specifications of 'the good' referred to in the first principle. If we interpret the principle as a formal one, 'the good' merely refers to the fact that practical reason is active, but that we can do without nature in order to arrive at sound conclusions about the courses of action to be taken. According to Grisez and Finnis, nature plays no important part at all. The mere distinction between theoretical and practical reason, each with its own fundamental and self-evident principle, testifies to Aquinas's awareness of the fact that moral judgements are the outcome of practical reasoning, not of any theoretical investigation of nature.

From end to end of his ethical discourses, the primary categories for from the Aquinas are the 'good' and the 'reasonable'; the 'natural' is, from the point of view of his ethics, a speculative appendage added by way of metaphysical reflection, not a counter with which to advance either to or from the practical prima principia per se nota,(34)

This interpretation deviates from the standard view shared by both Neo-Thomists and legal positivists, that the 'good' as the end for mankind, is informed by Aquinas's catalogue of natural inclinations.

I think that also here, the analogy with art is capable of resolving the dispute. If we regard natural law as the expression of the possibility for rational beings to adopt the divine style, it is clear that the general first principle is not sufficient in itself. There is no style, neither artistic nor scientific, that contents itself with the formulation of methodological guidelines alone. Schonberg's style cannot be transmitted by only explaining the atonal system; one should hear his music in order to compose in his style. Someone who has never seen an impressionist painting is not able to paint in that style. The study of scientific methods does not turn someone into a good scientist. Apart from guidelines, one should have access to the works of art in which a certain style is expressed.

God must have been aware of this wisdom as well. And that is why Aquinas thinks that we human beings can 'grasp' his style by looking at the products of the Supreme Artificer. So we might say that it is in ourselves, as God's creatures, that we find the examples of God's style, the greater part of which he has equally expressed in animals and plants. An investigation of these inclinations and ends in nature is therefore a heuristic device in order to know and to adopt God's style.

This interpretation allows me to adopt a middle-course between the conflicting interpretations. It is true that natural inclinations should not be seen as examples to be copied. Aquinas did not conceive of reason as a mechanical translation of is-statements into ought-state- ments. An understanding of God's style is more than following successful examples. In this sense, the contemporary natural lawyers are right to reject the kind of automatic inferences legal positivists have in mind when they speak about natural law. But Finnis and Grisez exaggerate matters by claiming that we should not rely on information about nature at all, or that nature is entirely irrelevant for practical reasoning.

5. Fullness of being

In order to assess the importance of the information nature provides, it should be noted that the first principle of natural law is embedded within two metaphysical assumptions. The first is a general statement concerning the nature of 'the good'; the second refers to the inclinations that are implanted in all creatures.

The general assumption is introduced just before Aquinas's formulation of the first principle:

[...] the first principle for the practical reason is based on the meaning of good, namely that it is what all things seek after.(35)

And it is here that Aquinas draws a parallel with theoretical reasoning: just as the first principle of practical reasoning is based on the meaning of 'good', the principle of non-contradiction is based on the meaning of 'being' and 'non-being'. The principle is evidently supported by the metaphysical assumption that all things seek after the good. But this is not the only definition of the good. He also identifies the good with 'an end':

[...] every agent acts on account of an end, and to be an end carries the meaning of to be good.(36)

In order to understand the equation of 'good' with 'end' we have to bear in mind the hierarchical and teleological framework of Aquinas's theory. 'Good' is not simply the opposite of 'evil', but is seen as a quality of being. The well-known Thomistic adagium 'bonum et ens convertuntur' can only be understood on the basis of Aquinas's view that good is fullness of being, and evil the lack of being:

[...] the good and evil of an action [...] depends on its fullness of being or its lack of its fullness.(37)


Thus a blind man has a quality of goodness for being alive, yet it is an evil for him to lack sight. (38)

It is clear that Aquinas does not conceive of the relation between good and evil as a dichotomous relationship. It is Aquinas's view that there are degrees of 'goodness' which run parallel with degrees of 'being'. In order to do justice to that view, we should not visualize his views as a horizontal, linear relationship of which good and evil are the extremes. The relationship between good and evil should be represented as a pyramid, in which each step higher means more fullness of being (good), and each step lower implies less fullness of being (evil). The definition of the good on which the whole edifice of natural law is erected, is informed by Aristotelian metaphysics in which all things strive towards fullness, perfection and the actualization of their potentialities. Viewed in this light, we can now understand why Aquinas formulates the first principle. It requires people to conduct their practical reasoning on the basis of the assumption that it is fullness of being we strive after and that we should not hamper that natural inclination.

The pyramidal representation of good and evil as more or less fullness of being implies that good and evil are notions, relative to the position one occupies at the scales of the pyramid.

If you find yourself at a level of being which corresponds to stage B, any action which leads to a descent to C is to be considered as a morally bad action. Of course, for those who start at D, the ascent to the same stage C is quite an improvement; the actions leading to such an ascent should be regarded as morally good.

The first principle ('good is to be done and pursued, and evil avoided') is, of course, of no avail in determining the position one occupies on the scales. It only tells us that the general direction should be upwards, because it is in the nature of all beings to move upwards. And in this general sense, Hart is certainly right in his sketch of teleological thinking. It seems that Finnis and Grisez cannot cut loose the first principle of natural law from the teleological metaphysics in which it is embedded.

However, if nature's role would be confined to the general statement that it is in the nature of things to move upwards on the scales of being, we might not really find that a helpful clue in deliberating on desirable courses of action. Although such a general role of nature would be theoretically significant, it might indeed be discarded as something that is not very relevant to our actual practical deliberation.

Aquinas, however, does not rest at this general statement. Immediately after the introduction of the first principle Aquinas adds more detailed metaphysical assumptions. Here he indicates the position on the scales occupied by mankind. To quote him in full:

The order in which commands of the law of nature are ranged corresponds to that of our natural tendencies. Here there are three stages. There is in man, first, a tendency towards the good of the nature he has in common with all substances; each has an appetite to preserve its own natural being. Natural law here plays a corresponding part, and is engaged at this stage to maintain and defend the elementary requirements of human life.

Secondly, there is in man a bent towards things which accord with his nature considered more specifically, that is in terms of what he has in common with other animals; correspondingly those matters are said to be of natural law which nature teaches all animals, for instance the coupling of male and female, the bringing up of the young, and so forth.

Thirdly, there is in man an appetite for the good of his nature as rational, and this is proper to him, for instance, that he should know truths about God and about living in society. Correspondingly whatever this involves is a matter of natural law, for instance that a man should shun ignorance, not offend others with whom he ought to live in civility, and other such related requirements.(39)

This passage indeed reveals that there is no fundamental gap between man and the rest of God's creation. As far as we have the inclinations to self-preservation and procreation we are, like the other creatures, expressions of the divine style. But we have also something extra which elevates us to a position of more perfection than the lower strata. That implies that although we have higher aims in life than the animals, we are not absolved from the duty to preserve ourselves and to procreate.

This raises the question what we should do if the various natural inclinations conflict with one another. What should someone do who is confronted with the choice between self-preservation and truth of God? What is the Christian supposed to do who is confronted with the choice either to die or to convert to Islam? Should the lower aim (self-preservation) come first or is it the other way round and is Aquinas advocating an attitude in which man should always seek his higher aims, and pursue the truth about God in the afterlife, at the cost of hindering the lower aims?

Finnis and Grisez simply deny that Aquinas's hierarchical ordering has any moral implications, if we are confronted with such a dilemma between competing inclinations. Finnis claims that

[...] Aquinas's threefold ordering quite properly plays no part in his practical (ethical) elaboration of the significance and consequences of the primary precepts of natural law [...].'(40)

This looks like an easy way out. In this view, Thomas gives us no clue whatsoever about the priority of goals in case they conflict. Goods such as self-preservation, knowledge, or social life are all simply conceived of as 'basic goods' and it is for practical reason to decide which of these goods should have priority in case of conflict. Therefore Finnis thinks that the principles based on these inclinations should be regarded as just some more guidelines, complementing the first principle of practical reasoning. He therefore speaks about the first principles of natural law not being derived from any statement of fact.(41)

This is, however, an unsatisfactory solution. Time and again Aquinas differentiates between ends that are desired for their own sake and ends that are desired for the sake of some further goal. This is clearly expressed in the Commentary on the Ethics:

Some ends we choose only for the sake of something else; e.g. riches which we do not desire except in so far as they are useful for a human life [...]. It is clear that all these ends are incomplete. But the best and last end should be complete. Hence if there is only one thing that is complete, it should be the last end which we are seeking. But if there are many complete ends, then the most complete of them should be the best and last. (42)

According to Aquinas, ends such as self-preservation and procreation cannot be regarded as complete ends. The 'most complete end' in Aquinas's vocabulary, (43) is knowledge of God. This is truly an end which is desirable for its own sake. We might therefore expect Aquinas to give priority to the more complete end if it conflicts with a less complete end. This does not imply that Thomas shows contempt for these lower aims. They are not 'merely' instrumental. (44) On the contrary, less complete ends are 'sub-ends'. They have a value in themselves, since they are the realisations of the tendencies that are implanted by God. The only thing that is required from us is that we should be aware of the incompleteness of these ends in our practical reasoning. To think that self-preservation should be given priority over knowledge of God is simply making a mistake in the assessment of the degree of completeness of these aims. To give priority to those lower ends is to forsake the divine spark in us which enables us to adopt the divine style. To pursue less complete ends at the expense of a more complete one is to treat oneself as merely an artistic product; not as the artist one can—also—be.

6. Desired and desirable

We might wonder whether this interpretation of the role of nature, as outlined above, is so much different from the standard Neo-Thomistic interpretation, that the first general principle should be viewed as a major, which, coupled with informative minors, gives rise to moral rules. The observation of the various natural inclinations towards ends informs us about the morally desirable ends to pursue. It seems then, that all my talk of eternal law as 'style' and natural law as our adoption of that style is no more than an unnecessary 'aesthetisation', a futile attempt to make Thomism somewhat more palatable to the taste of the post-modern reader and to conceal the undeniable fact that indeed, it was Aquinas's view that we can infer norms from nature without more ado.

At first sight, this appears to be the case. In the preceding section we have seen that Aquinas offered two definitions of 'the good'. The first is 'that which all things seek'; the second equates the good with an end. The two definitions recur in De Veritate:

Since the essence of good consists in this, that something perfects another as an end, whatever is found to have the character of an end also has that of good. Now two things are essential to an end: It must be sought or desired by things which have not attained the end, and it must be loved by things which share the end, and be, as it were, enjoyable to them. (45)

There seems to be an ambiguity involved here. On the one hand, Aquinas conceives of the good as that which is 'perfective' of man's nature, in the sense that it helps man to realise his ultimate end. In this sense the good is thought to be objectively desirable. On the other hand, he stresses that the good must be loved and found 'enjoyable'; in other words, the good must be desired. The juxtaposition of these two definitions suggests that Aquinas simply conflated the factually 'desired' with the normatively 'desirable'.

In order to clarify the troublesome position of this twofold definition, it is useful to look into a passage in the Summa, where Aquinas comes to speak about the three ways in which reasoning can be called theoretical or practical. (46) Reasoning can be called theoretical or practical as regards its object, its method and its end. For instance, if a builder considers how a house can be built, but does not actually build that house, his object is practical, but his end is theoretical. His reasoning is partly theoretical, partly practical. (47)

In order to understand the differences between practical and theoretical reason it is worthwhile to see what they look like, if they are completely theoretical or practical in all three aspects. Based on Aquinas's assertions on how the two kinds of reason run parallel, the following order can be reconstructed:

theoretical reason practical reason
object being and non-being the good
method principle of non-contradiction good is to be done etc.
end the truth. the good

We immediately perceive a remarkable incongruity here. For we see that in the domain of theoretical reason 'object' and 'end' are different: being an truth do not coincide. But in the domain of practical reason the good is both object and end of practical reasoning. It is that which all men seek and the ideal to which we should strive. It seems as if this little exercise indeed reveals the profound confusion between 'is' and 'ought'; between 'desired' and 'desirable'. Oddly enough, the definition of the good as both 'that which all men seek' and 'the end', does not raise any scepticism among Neo-Thomists. They even conclude that the twofold definition of the good proves that there is no inference here from the desired to the desirable. This is the position of Ronald Duska,(48) who concludes from the above-quoted passage that an end can be counted as 'good' if it fulfils both the criterion that it is actually desired and that it is desirable (because of its perfective qualities):

Aside from being desired and enjoyed, any candidate for being called 'good' must also be perfective.(49)

Duska concludes, that by stressing both elements Aquinas avoids the pitfalls of the position in which the desirable is simply inferred from the desired and it equally avoids the (non-naturalist) position in which the desirable is completely independent of what is actually desired by people.

I believe that this interpretation is too easy. If the problematical relationship between the normatively desirable and the factually desired could have been solved by a mere juxtaposition of the two, it is hard to understand why such a long and fierce debate would have ensued. The problem is that Aquinas needs a criterion in order to decide which good is more 'complete' or more 'perfective' of our being than another good. The question is whether this criterion itself depends on the degree in which this end is actually desired by people or not. If so, there would be reason to think that according to Aquinas the most desirable good is the good which is most desired.

The above-quoted passage from the De Veritate does not help us decide whether this is indeed the case. More information is given by Aquinas in a passage in the summa where our purpose in life is discussed.There Aquinas draws a highly important distinction, which I quote in full:

We can speak of the ultimate end in two senses, namely to signify first what it means, and second that in which it is realised. As for the first, all are at one here, because all desire their complete fulfilment, which, as we have noted, is what final end means. As for the second, however, all are not unanimous, for some want riches, others a life of pleasure, others something else. We draw a comparison here with the palatable, which is pleasurable to every taste. Some find this in wine most of all, others in sweetstuffs or something of the sort. All the same, by and large, we esteem that most palatable which most appeals to cultivated tastes. And likewise we ought to account that good the most complete which is finally sought by those with well-tempered affections.(50)

In this passage', the desired and the desirable are not merely juxtaposed but serve as answers to two different questions. Asked for a definition of the ultimate end (the so-called first sense) he merely repeats his definition of the good, which is simply that which all men seek. Aquinas says that 'all are at one here'. Of course they are: if we define the good as the desired, it is a somewhat trivial truth that it is the good that we all desire. The real problem arises as soon as we start to look for an objective criterion in order to answer the question whether the desired is that which should be desired. About that answer there is lack of consensus, Aquinas says. No objective criterion seems to be available. In that case we should follow those with a 'cultivated taste': we should follow the virtuous man.(51)

This solution is surprisingly similar to the criterion J.S. Mill invoked in order to decide which kind of happiness should be pursued:

Of two pleasures, if there be one to which all or almost all who have experience of both give a decided preference [...] that is the most desirable pleasure.(52)

Mill tried to refute the criticism raised by his opponents that utilitarianism simply inferred desirability from the desires of 'swine', by arguing that a cultivated person who is acquainted with lower pleasures as well as higher pleasures would opt for the higher ones. Mill and Aquinas both share the view that the ends which are truly desirable are desired by persons with a cultivated taste.

This does not turn Aquinas into a utilitarian, although I believe that there are more similarities between the two doctrines than is commonly recognised. The main difference between the two philosophers is that Mill does not provide us with an answer to the question how we can recognise the truly cultivated man. His treatise vaguely evokes the picture of the educated gentleman, but it is unclear what exactly this gentleman's abilities should be. Apart from that, the claim that the gentleman should also be acquainted with the lower pleasures is confusing. In order to be persuaded that indeed 'it is better to be a Socrates dissatisfied than a fool satisfied', (53) we have to know for sure that Socrates had some experience with brothels, drugs or laziness and consciously opted for philosophy as a higher pleasure.

All these confusions are absent in Aquinas's account, for the cultivated person we should follow is not merely marked by 'taste'. His moral behaviour is not only marked by 'well-tempered affections' but, more importantly, by the fact that the ends he pursues are guided by practical reasoning:

The natural inclination to the good of virtue is a kind of beginning of virtue, but is not perfect virtue. In fact, the stronger this inclination is, the more perilous can it prove to be, unless it be joined by right reason[...] just as, if a running horse be blind, the faster it runs the more heavily will it fall, and the more grievously be hurt.(54)

On the basis of these quotations it is not difficult to assess the relationship between good as the object of practical reasoning and good as the end of practical reasoning. They do not simply coincide. The object of practical reasoning is the good towards which we have a natural inclination (that which all things seek). That good simply refers to that which is desired. But although this is 'the beginning' of true virtue, and as such can serve as an indication where the good should be sought, it is not enough. 'Good' as the end of practical reasoning is that which is truly desirable. In order to assess the desirability of our desires, we should rely on practical reasoning and on the moral behaviour of the well-informed man. In order to avoid confusion, I believe that Aquinas's views on the differences between practical and theoretical reason can be reconstructed as follows:

theoretical reason practical reason
object being and non-being the desired good
method principle of non-contradiction good is to be done etc.
end the truth the desirable good

Just as the truth is the result of sound reasoning about being, the desirable is the product of sound reasoning concerning the good we naturally seek.

It is important to note that taken in this sense the desirable is not simply inferred from the desires people have. These desires do not serve as the only basis from which ought-statements are derived. Aquinas is not a naturalist pur sang. The style-metaphor is more apt to describe the more complex kind of reasoning Aquinas had in mind than the standard interpretation in which rules are the product of simple inferences.

But at the same time Aquinas avoids the pitfalls of those who claim that the determination of the ends one should pursue is completely independent of what people desire. As we shall see in IX.6, this is the view Finnis reverts to. In the modern theory of natural law, the actual desires of people are discarded as irrelevant. Aquinas avoids both pitfalls, not because he equally values both the desirable and the desired (as Duska would have it) but because the process of reasoning forms the missing link between the two.

7. Conclusion

The debate whether Aquinas's theory should be regarded as a set of inferences of norms from nature, or as an attempt to develop a theory of practical reasoning, which is independent from nature, seems to be marked by a tendency on both sides to underestimate the unifying potential of the concept of eternal law.

In this chapter we have seen that once we take seriously Aquinas's view of God as Artificer, the eternal law is not strictly speaking a 'law', but can be more adequately understood as a style that regulates and directs God's creation. Such an interpretation clarifies the position occupied by the various creatures within the eternal law. The natural inclinations which animals, plants and human beings have in common, can be seen as artistic products: as expressions of the divine style. The natural inclination to rationality (in angels and human beings) enables these beings to participate in the divine style, i.e. to adopt that style in regulating and ordering their own affairs. Natural law is nothing more than a term denoting that capacity of rational beings.

The reading of eternal law as style makes clear that God Himself is not obliged to 'obey' that eternal law. He simply created the world according to a consistently applied self-imposed style. Nor is it necessary to suppose that natural law needs extra obligatory force for us to comply with that law. There is no need for us to look for an additional expression of God's will. Aquinas simply presupposes that we have no other alternative than to adopt the divine style, albeit imperfectly. The very promulgation of the style entails its obligatory force. There is no gap between reason and will. Secondly, since rational beings are not able to adopt a style on the basis of some general stylistic requirements alone (such as the first principle of natural law), we should rely on the additional information concerning God's style that is furnished by His products: the inclinations in all created beings. In order to reason well, we should be informed by the expressions of God's style that can be found in both human nature and in the natural inclinations we share with the irrational beings. As the term 'style' suggests, we should not use this information as examples to be copied in a mechanical way, as Hart supposed. But neither is it advisable to discard nature, as Grisez and Finnis do, as an important source for information and to rely on our rationality alone. The concept of eternal law, if we regard it as style, does not allow for a gap between nature and reason.

The absence of any gaps between reason, will and nature implies that it is Aquinas's view that God's will is manifest in the particular style He adopted. In this sense, Kelsen is certainly right that natural law theory depends on the assumption that God's will is immanent in nature. But it is not only an expression of will: God's style is also reasonable, in the sense that it is accessible to human reason. Finally, His style is natural to the extent it is expressed in the creation. In this sense, what God wills is reasonable and natural at the same time. Obviously, that does not imply that what we human beings will is reasonable and natural at the same time. Although there is no other option available than to adopt God's style, it is not certain whether we apply that style in a successful way. We can try to connect our natural inclinations to the rational perception of what is really 'perfective' of our nature, but whether we succeed in doing that and opt for the correct course of action in pursuing the good depends on the way we actually proceed within the parameters of the divine style. Are we successful as artists, working in the image of God? To that question we return in the next chapter.


1. Kelsen, 1963,p. 129.
2. Hart, 1961, p. 185.
3. Mill, 1874, p. 28. Mill's view of nature was not influenced by Darwin, since he had not read Darwin when writing this essay.
4. Grisez,1965.
5. 'Bonum est faciendum et prosequendum, et malum vitandum.'
6. ST I,II, 94, 2.
7. Taken as a moral injunction, 'should be' is more appropriate than 'is to be'.
8. The theory proposed by Adler is inspired by such an interpretation of Aquinas. Cf. Adler, 1981.
9. Finnis, 1983 (abbrev. FE), p. 14.
10. Grisez, 1965, p. 368; NLNR p. 34; Boyle, 1992, p. 25.
11. Cf. Kühn,82.
12. ST I, II, 94, 2, concl.
13. Grisez 1965, p. 369.
14. ST I, II, 91, 2, concl.
15. Ibid.
16. The other available gateway is divine law, the direct expression of the eternal law as revealed by God Himself in the Scriptures.
17. ST I, II, 93, 1.
18. ST I, II, 93, 1.
19. Cf. Gombrich, 1950, p. 147.
20. Mill, 1874, p. 19.
21. Eco, 1988.
22. Eco, 1988, p. 98.
23. Eco, 1988, p. 101.
24. ST I, II, 90, l.
25. Lottin, 1931, p. 97.
26. We should be cautious, however, not to identify 'style' with 'personal style'.
27. James, 1906, p. 77.
28. ST I, II, 90, 1, concl.
29. ST I, II, 91, 2, ad 3.
30. ST I, II, 91, 2, concl.
31. ST I, II, 90, 1, ad 1.
32. Cf. Grisez, 1965, p. 367; Lottin, 1931, p. 75.
33. Fleck, 1935, was the first to introduce the concept of style in the analysis of science. For a more recent overview see: Hollis and Lukes, 1982. Of course, these theories start from the assumption that there are several possible styles of reasoning, whereas Aquinas did not allow for such a variety.
34. NLNR p. 36.
35. ST I, II, 94, 2.
36. Ibid.
37. ST I, II, 18, 2. This quotation is taken from the Pegis edition, 1944, since the Blackfriars edition translates plenitudo essendi as 'completeness of reality' which gives the expression
an objectivist flavour that might be misleading.
38. ST I, II, 18, l.
39. ST I, II, 94, 2. It is not clear to me why in the Blackfriars edition praeceptum is translated as 'command' instead of 'precept'. It gives the passage an unnecessarily voluntarist ring.
40. NLNR p.94
41. As we shall in IX.4, the rejection of any hierarchical ordering here causes enormous problems for their own moral theory.
42. Bk. I, lect. 9, in Martin, 1988, p. 171.
43. Nowadays, one might be inclined to think that completeness admits of no degrees, but also here Aquinas's gradual and hierarchical ordering has to be taken into account.
44. As we shall see in chapters IX and X, this is how incomplete ends figure in Finnis's account.
45. De Veritate, 21, 2.
46. Cf. also Mclnerny, 1981, p. 39.
47. ST I, 14, 16.
48. Cf. Duska, 1974.
49. Duska, 1974, p. 153.
50. ST I, II, I, 7.
51. Cf. also O'Connor, 1967, p. 28.
52. Mill, 1863, p. 8.
53. Mill, 1863, p. 9.
54. ST I, II, 58, 4, ad 3.