I. Aristotle, Sociability and Natural Law

In the Politics I.2, Aristotle seems to derive natural laws from human sociability. The human being, we are told, is gregarious to a greater extent than any other sociable animal, and the polis is analytically prior to either the household or the individual. For both of these are radically incomplete and undeveloped without society, and are unable to attain even very modest human goods that are required for a genuinely human life.Footnote ¹ Above all, the political state is founded upon law and justice, without which human beings are the most depraved of animals.

Law, then, is natural to human society, and thus naturally a part of the human condition. But the law that is spoken of here is positive law, the rule of the ‘great benefactor’ by whose actions (undisclosed by Aristotle) human beings are brought into a society. Furthermore, Aristotle's subtle analysis of the political state and — by extension — peaceful sociability leaves intact all of the ethical problems at the focus of ancient ethics, beginning with the question of why one ought to have any concern for the wellbeing of others, and by what means the gap between one's own self-interest and the interest of others is to be bridged.Footnote ² Such explanations are to be found elsewhere in the Nicomachean Ethics, in its treatment of friendship [philia]. Here one's actions for the sake of the other aim to increase the wellbeing of the friend, whose wellbeing is a part of one's own wellbeing.Footnote ³ But Aristotle extends the notion of philia, by pros hen homonymy, to cover good relations between citizens, not only friends.Footnote ⁴ Such relations, of friendliness rather than friendship, are the basis of justice in the community. Yet nowhere in the ensuing miniature treatise on politics (VIII.8-11) does Aristotle ever state the principle by which concern is to be manufactured for fellow-citizens who lie outside the family circle.

The most that Aristotle will say is that concord, which lawmakers aim above all to secure, is more akin to friendship than to justice, so that it is through a form of friendship that the community is held together. Indeed justice in the community requires an element of friendliness.Footnote ⁵ This may seem to mix interested and disinterested forms of relationship, but Aristotle perhaps has it in mind that human societies are made up of smaller kinship units, families and circles of friends: hence human communities are not made up of sheer individuals who meet one another as equals and strangers in all their interactions. But Aristotle famously denies the suggestion, encountered in Plato's Laws, that all things are to be shared with all people: for it is possible to share one's own material wealth and stores of affection with only a few.Footnote ⁶ So Aristotle falls back on an alternative proposal, that concord consists in an agreement in judgments, the agreement of mind with mind, in relation to matters of communal importance.Footnote ⁷ Prime among such matters are the determination of how offices and advantages are to be shared, and what is just and beneficial.

But the association of justice with the ‘political friendship’ between citizens does not amount to the derivation of natural laws from human sociability. For Aristotle's ethics neither embodies nor contains a natural law theory in the proper sense. Natural law, in the proper sense of the term, is both a theological and a secular idea. As a theological idea, natural law is (as Thomas Aquinas says) ‘a participation of eternal law in the rational creature’:Footnote ⁸ reason's revelation of knowable truths of eternal law variously additional to or confirmed by divine law, the part of eternal law that is directly revealed by holy texts. As a secular idea, natural law explains how pagan philosophers to whom the divine law was never revealed were nonetheless able to arrive at authentic moral truths: not indeed by mere accident or coincidence but on the basis of reason's operation.Footnote ⁹ A natural law theory can explain the work of a philosopher who has no natural law theory. For Aristotle does not possess, as Aquinas does, the idea of an external (as well as an internal) principle by which God moves human beings to the good,Footnote ¹⁰ but takes as his starting point a discussion of voluntary action and rational choice [prohairesis].Footnote ¹¹ Aristotle's ethics may be teleological and functionally ordered to characteristic forms of human flourishing, but it lacks the reality of providence in that ordering, and the careful dissection of inclinations that one finds in Aquinas. Indeed, Aristotle discussed both ethics and politics without invoking theological considerations.

In order to consider the derivation of natural laws from human sociability, it is therefore necessary to look beyond Aristotle to the Christian philosophies of the ancient and medieval periods. Specifically, it will be instructive to examine the works of St Augustine and St Thomas Aquinas. Although drawing upon elements of Aristotelianism, neither philosopher merely baptises Aristotelian thought. The present concern, however, is not with the history of ideas, but with the substantive question of how, or whether, natural laws can be derived from human sociability. Historical comparisons will therefore be explored only where they are useful to the primary question.

The philosophies of the Christian writers on law and politics were concerned with the realities of both heaven and earth. One of these realities in particular dominated the Biblical and philosophical tradition down to Thomas Aquinas: the reality of humankind's sinfulness. Nowhere is this more evident than in the writings of Saint Augustine.

II. Augustine's View of Sociability

In the famous nineteenth chapter of De Civitate Dei, Augustine offers the second of two general definitions of a ‘people’. A people is:

Here Augustine suggests that it is too great an expectation to expect laws to derive from the formation of a political community. Instead one can only expect a degree of consensus on goals worth pursuing.Footnote ¹³ Implicitly, a shared consensus on goods to be pursued is also a shared consensus on evils worth avoiding: in a good community, the objects of aversion would include, for example, sins against justice, harms toward the innocent, internal lawlessness and so forth. But not all communities are good communities, and Augustine clearly regards it as possible for a community to accept as a ground of its association precisely those evils that the good community seeks to exclude: even the political arrangements of the greatest state (Rome) resemble the internal, misdirected justice of a criminal organisation.Footnote ¹⁴

Two considerations are worth mentioning in relation to the foundational consensus on objects of love. The first is that it is not a sociable impulse to love one another, but an agreement in choice about loving ‘external’ goods such as material wealth, honour, etc. or indeed God Himself. The second consideration is that this choice is not entirely free, for it is directed to what is valuable in those objects, whether this be a false value or a real value. But false values can only be loved (that is, regarded as values) under the aspect of goodness: they are not loved and grasped as evils per se. Nor is love arbitrary: for love does not place value into the object, but depends upon the value of the object. Love is in this sense a (re)cognition of reality, and better or worse loves are differentiated by virtue of the adequacy of their grasp of these realities.Footnote ¹⁵

For example, material goods are not to be sought and celebrated as the ultimate end, but (as Aristotle observes) they are nonetheless indispensable in assisting the virtues, as well as bodily health: for one cannot give to others except by having property to give. There are — always — genuinely good properties of material goods, even on those occasions when they are chosen wrongly, for the wrong purpose, with the wrong intention, on the wrong occasion, and so forth.Footnote ¹⁶ Our grasp of such goods is far from unproblematic. Here is an instance of the Aristotelian principle that one should not look for more precision than is inherent in the subject-matter: for general rules will yield only general conclusions. Indeed at the level of particular situations, the grasp of good and evil, like the attribution of praise or blame, is often a matter in which reason must be guided and supplemented by perception.Footnote ¹⁷ For most situations, and most choices, will involve an option for good in which some evil consequences are mixed.

Elsewhere in the same passage as his definition of a ‘people’, Augustine says that the welfare of a people is its degree of internal peace and harmony [concordia]. Peace is the highest good: both the peace in eternal life, and peace in earthly affairs.Footnote ¹⁸ Even those who wage war and indulge in acts of violence desire peace as the end of action, however misguided, selective or generally insufficient their notion of peace may be.Footnote ¹⁹ Peace between human beings is ‘an ordered agreement of mind with mind’,Footnote ²⁰ not merely of bodies in proximity. When human beings follow their natural instincts, ‘the whole use of temporal things is directed toward the enjoyment of earthly peace.’Footnote ²¹

The truth of this natural tendency toward peace can be demonstrated by considering the situation in which a community lacks peace. In such a situation, there can be no possibility of safely pursuing any other human good, for one's basic existence is under constant threat. There can be no common goods, such as laws or public order, for even the most tyrannical government is incapable of imposing peace without gaining the organised cooperation of members of the community (including by fear). There can be no collective endeavours, such as the joint effort to build commodious buildings, or to grow and distribute food. There can be no professions, such as the practice of medicine or of teaching. All such human goods would be limited to the efforts of households which, as Aristotle remarked, are in these crucial respects insufficient to provide for the flourishing of their members.Footnote ²²

Peace represents a natural tendency because it forms a universal end for all persons. Precisely because it is necessary for every end, peace is objectively valuable for every person, without exception, both (1) irrespective of their conception of further ends to be pursued, including the ultimate end; and (2) even if they fail to perceive its importance. For peace is valuable even to the wicked person who fails to recognise it as an essential element of the situation they seek to bring about. Even the most aggressive person requires rest from contention the majority of the time. But peace is in its proper nature a common good, for it can be brought about only by the common will and effort of all persons within a community, or faction, or group, or household…

Augustine was well aware that peace (in the sense of an imposed or coerced lack of disorderly contention, i.e. corrupt peace) could stem from a wicked person's inordinate love of self. In such a case, the wicked person does not value others except as means to the fulfilment of private goals. The peace that is achieved is good only in a heavily reduced sense. But Augustine regarded the root of true peace as love of neighbour, the love that extends beyond oneself to embrace the other as (in Aristotle's words) ‘another self’.Footnote ²³ This is the peace of orderly harmony [ordinata concordia] with all others; and the precepts which bring such order about are first, that of avoiding harm to others, and secondly that of doing good to others so far as this lies within one's powers.Footnote ²⁴ These precepts arise out of the human being's sociable nature,Footnote ²⁵ first of all in households, to which one's mode of belonging is both natural and societal.Footnote ²⁶ From this domestic peace there comes, by an extension of that internal harmony of households, a civic peace, a wider sharing in the human goods that flow from orderly relations with others.Footnote ²⁷ But Augustine leaves it in no doubt that the social instinct of human beings, a sociability in any case lacking in all except the wise,Footnote ²⁸ is hardly strong enough to form a stable basis for civic peace. For human affairs are not settled; they ever consist of ‘suspicions, hostilities and war’, causing enmity even within households.Footnote ²⁹ Thus the true source of those precepts of peaceful order is that of God's love, commanding us to love ourselves for the sake of God who created us, and to love our neighbours, also so created, as we do ourselves.

Yet, Augustine does not mean to suggest that civic peace is only a possibility for those who have accepted the mandates of divine law. Christian polities do not have a monopoly on public order. He therefore begins the discussion by observing that he will rely not only upon divine authority but will also, ‘for the sake of unbelievers,’ make ‘as much use of reason as possible.’Footnote ³⁰ This, however, will be public peace in a reduced and qualified sense: a ‘clever pretence’ of peace amid ‘common evils’ that ever threaten the community;Footnote ³¹ a form of disciplina rather than concordia.

The twin precepts of peace (avoidance of harm and doing good) are nevertheless clearly expressive of natural laws. For peace in the central, proper sense is natural, and remains so even if the evils of war or disordered peace are the normal experience of human communities. The central case of a concept is formed from the most flourishing and developed incarnation of the concept, not the case which is most prevalent or in potentia. It remains not as an ideal but as a fully realisable standard even in the midst of deflecting actions, unreasonable motivations and improper aims. Furthermore, ‘nature’ has not permitted human beings ‘to wander too far from the path of truth’,Footnote ³² for human inclinations impose constraints on practical reason's ability to desire false goods (i.e. actual evils) or to avoid supreme good. It is possible to perpetuate such errors only by failing to subject the underlying thinking to the unrestricted flow of reason, by cutting off practical reason's deliberations prematurely. The person who so ignores or desists from practical reason's efforts succumbs to ‘an endless, aimless evil’, a loss of boundaries characteristic of the life of an outlaw rather than a civilised person.Footnote ³³

Such evil consists in, and is consented to by, a view of the human mind as the source and meaning of value; and it is avoided by the realisation of the mind's restraint by the realities known as natural laws: its intellection of forms of good and evil, and of precepts of right and wrong to be applied in action. A mind thus constrained by natural laws can be said to be in good order, in harmony with itself and with reality, as opposed to a mind devoted to conflicting pleasures and experiencing mere episodes of fulfilment.Footnote ³⁴

Natural law precepts are not, then, (as Hobbes later said) mere ‘theorems of prudence’: moral theory cannot rest only upon enlightened self-interest or self-interest modified by the interests of others. Such reciprocity is not morality, but merely the realisation that I cannot have the things I want unless you have them too. Moral wrong is not simply the loss to one's interests rebounding from bad deeds to others. Moral wrong is the estimation of truly bad things as good, and correspondingly of evil actions as to be pursued, in defiance of the true order of nature — such as pleonexia, or contention with one's neighbours — in which the mind consents to the demands of a perverted will.Footnote ³⁵ Faced with the possibility of evil choices, the natural law precepts (of avoiding harm and doing good) both enable reasoning (by affirming the existence of human goods) and constrain reasoning, by exposing bad suggestions, resisting base pleasures, and withholding consent to evil indulgences.Footnote ³⁶ They suggest, too, further requirements of peace, such as justice, even if a properly just peace is unavailable in present life.Footnote ³⁷ For there can be no stable peace without a measure of justice. It is such natural laws that are at work in Socrates's answers to the careless ripostes of Callicles in Plato's Gorgias, that it is better to suffer injustice than to do it.Footnote ³⁸ For one should be prepared to forego one's legal right to repayment by a debtor if pressing one's claim would cause his or his family's destitution.Footnote ³⁹

These doctrines concerning right, justice, harm and evil must be intelligible and true (as they are) independently of the subsequent description of eternal damnation and reward. A person who leads a blameless life only out of fear of hell, or desire for paradise, has fundamentally mistaken the nature of their true good.Footnote ⁴⁰ Against this ‘selfish’ desire for reward there is the recognition of the intrinsic goodness of all steps leading toward paradise, including good relations with one's neighbours. True neighbourly love cannot be selfish: for it is to ‘draw [one's neighbour] to that good which you are yourself pursuing.’Footnote ⁴¹ Here is Augustine's clearest derivation of natural laws from human sociability, for it is (he says) from this precept of neighbourly love that ‘proceed the duties of human society,’ duties that encompass both body and soul.Footnote ⁴²

Human sociability is both a fact and a norm: it is at once an extant condition, grounded in powerful human inclinations, and an ideal condition that is only partially instantiated in present reality. Augustine's derivation of natural laws of peace from our sociable nature is a derivation from the norm of sociability, specifically the commandment to love one's neighbours. This commandment would not make any sense were it not that human beings possess powerful social inclinations, but it remains that human beings also possess sinful inclinations (especially Aristotle's pleonexia) that are capable of qualifying or overpowering the disposition to act sociably. The root of all such inclinations is the sin that Augustine condemns above all: pride [superbia].Footnote ⁴³

This raises questions, not directly confronted by Augustine, of what it means to possess natural laws, and to what extent they can be eradicated by the influence of sin: matters much discussed and illuminated by Thomas Aquinas.

III. Aquinas on Natural Law and Sociability

The term ‘natural law’ appears, possibly for the first time, in Plato's Gorgias, where Callicles observes that ‘nature and law [physis and nomos] are for the most part opposites.’Footnote ⁴⁴ In the ensuing discussion, Socrates replies that not all law is conventional, for some laws have the force of nature.Footnote ⁴⁵ The remark is reminiscent of Aristotle's warning in the Ethics that the variation in political science's determinations of what is just makes it seem as though truths of justice and ethics exist only by convention and not by nature.Footnote ⁴⁶ This assertion that some ethical truths exist ‘by nature’ is crucially ambiguous and hence not very satisfactory. For it presupposes (without illuminating) some division between human actions that are expressive of, in accordance with, or ‘by’ nature, and human actions that are contrary to nature.

Now, Aquinas indeed recognises quite readily that most people and their actions are depraved and unreasonable.Footnote ⁴⁷ And to be depraved or unreasonable is to have a disposition that is contrary to what is in accord with one's nature.Footnote ⁴⁸ But the ‘nature’ of a being is the form by which it derives its species, which in the case of human beings is the capacity to be rational. Thus:

At the same time, human beings also possess a sensate nature (‘for it is through the operation of the senses that the human being achieves acts of reason’), and the prevalence of vice is explained by the fact that more people follow the inclinations of sensate nature than follow reason's order, in other words they fail to complete the train of reasoning that leads to right action.Footnote ⁵⁰ This is the case in sins of lust, for example,Footnote ⁵¹ all of which can be called unnatural.Footnote ⁵²

Aquinas does not conceive of sensate nature as inherently disordered, for the will (intellectual appetite) moves in us precisely through the sensory appetite.Footnote ⁵³ Thus, just as there are evil desires [concupiscentiae pravae] which are opposed to correct reason, there are also good desires [concupiscentiae bonae] that oppose perverted reasoning.Footnote ⁵⁴ Such good desires are the impression of eternal law on the rational creature, for human beings share with other animals a certain ‘participation of eternal law’, insofar as they acquire their respective inclinations to their proper acts and ends, and are in this sense subject to God's providence. But unlike other animals, human beings are (to some extent) ‘provident for themselves and others’, and this mode of participation ‘is called natural law’: natural reason's capacity to discern good from evil.Footnote ⁵⁵ Such principles are sometimes called upon directly in practical reasoning, but are at other times present in reason only dispositionally [habitualiter].Footnote ⁵⁶

Every person possesses knowledge of the most general [communissima] precepts of natural law: these are inscribed onto the mind, as a kind of dispositional potency [quasi habitus potentiae], in the same way that principles of geometry are inscribed onto the mind of one who understands geometry.Footnote ⁵⁷ They cannot be erased from the mind of any person, except for the knowledge of how they apply in specific cases, where reason is impeded from applying them due to desire or passion.Footnote ⁵⁸ But the immediate conclusions from those general precepts — natural law's secondary principles — can be erased from the mind, either by one's own evil tendencies or by vicious customs.Footnote ⁵⁹

These foregoing propositions can be summarised by stating that human beings’ rational (and to some extent sensate) nature is a source of natural laws. The good of human nature, its natural inclination to virtue, is not extinguishable even when it is diminished through sin: Aquinas uses the analogy of halving a substance, halving that half and so on, indefinitely.Footnote ⁶⁰ Even the damned continue to possess this natural inclination to virtue, though they do not act upon it.

As Aquinas implies here and elsewhere, human nature is best understood by considering its characteristic inclinations, as well as the objects or ends of those inclinations: that which fulfils them. Indeed, there is an order to the precepts of natural law that follows upon the order amongst natural inclinations. Reason does not impose this order, but discovers it; for ‘all those things to which the human being has an inclination are naturally apprehended by reason as being good … and their contraries as evil…’Footnote ⁶¹ For present purposes it is the second- and third level inclinations that are important. Second level inclinations (shared with all animals) include the conjugal union of male and female, and the raising and education of children. Third level inclinations (peculiar to human beings as rational creatures) include living in society with others, and thus the avoidance of offence to others with whom one ought to live in harmony. Both sorts of inclinations are social inclinations. They pertain to the way in which a person is united with others as part of a human community.

In virtue of second level inclinations, human communities do not come together as a collection of unrelated individuals, but are instead structured and composed of family units, households and broader kinship groups.Footnote ⁶² Such units ‘provide what is necessary for life’;Footnote ⁶³ they are utterly essential and their functions cannot be successfully usurped by the state. They provide the foundations for a good life, and thus the human being benefits from (and is subject to) domestic governance: such modes of governance therefore have the status of natural laws. These laws are a kind of domestic prudence,Footnote ⁶⁴ with the purpose not only of managing household expendituresFootnote ⁶⁵ and procuring the necessities of life, but also ruling the actions of the members, e.g. by distributing works.Footnote ⁶⁶ In this way, the family is ruled ‘by the law and precept’ of the head of the household,Footnote ⁶⁷ who has the natural authority to inflict minor punishments.Footnote ⁶⁸ The end of all such measures is the common good, or collective flourishing, of the household.

The sociable instincts that give rise to these laws and duties are stronger within the family than within the state as a whole. The chosen union between man and woman reveals that human nature is more conjugal than political.Footnote ⁶⁹ Children (ought to) love their parents with a special love that comes from their generation and nurturing,Footnote ⁷⁰ whereas parental duties pertaining to the raising of children last for an entire lifetime and not only until the children become properly independent.Footnote ⁷¹

Familial bonds in this sense represent a special case of the general love of neighbour that Christians are commanded to exhibit. But there is a more general inclination, at the third level, to live peacefully in society with others, and from this derive natural laws, amongst which is the duty to avoid offences against those with whom one must live in harmony [debet conversari] ‘along with other things pertaining to this inclination.’Footnote ⁷² Aquinas several times repeats Aristotle's dictum (which he takes Aristotle to have proved) that the human being is a political animal fitted for life in society.Footnote ⁷³ But elsewhere he seems to suggest that the corresponding natural laws are among those that may be lacking in one who fails to follow reason's order: for as he cautiously observes, ‘there ought to be [debet esse] a threefold order in human beings’:

Therefore, although a person necessarily possesses the inclination to live peacefully in society, they may lack the orderliness by which they are meant to relate to others. This is one way of being unreasonable; for ‘the first order encompasses the [second and] third order, and exceeds it, because in all matters by which we are directed to our neighbour, we must be directed by the order of reason itself.’Footnote ⁷⁵ Aquinas closes the reply by specifying what it means to live in peace with others: ‘by the theological virtues the human being is directed to God, by moderation and fortitude to himself, and by justice to his neighbours.’

Thus Aquinas divides the natural laws relating to social peace into two cardinal precepts: (1) refraining from offences against other persons; (2) the requirement to observe justice. Under the first of these precepts, there is obviously the duty to avoid criminal acts, such as theft or violent contention, including evading the just punishment of the state by, for example, absconding or denying one's crime.Footnote ⁷⁶ More broadly there is the requirement not to undermine or act against the public safety. The age-old positive laws prohibiting crimes of violence and serious forms of dishonesty are thus declarative of natural law, as even the positivist philosopher Hart appeared to recognise.Footnote ⁷⁷ The demands of justice, under the second precept, are yet more wide-ranging. Aquinas observes that acts of justice are directly related to the maintenance of peace between persons, for it leaves each person undisturbed [quiete] in their possessions.Footnote ⁷⁸ To refrain from that which belongs to another is precisely to leave them in peace. Conformity to justice is a direct contribution to the common good,Footnote ⁷⁹ specifically to the common good of peace. This is evident from the acts of justice that Aquinas specifically mentions, including: honouring one's debts, refraining from harms against another's person or property, not defaming or bearing false witness, and avoiding acts that threaten the community.Footnote ⁸⁰

It is frequently overlooked — although mentioned by GrotiusFootnote ⁸¹ — that a citizen's just acts are the means by which each citizen assists the state government in protecting the common good and suppressing evils. (For example, payment of taxes may enable the state to employ a police force or standing army to defend against internal and external threats to peace). But no less important is each citizen's willingness to forgive minor injuries, or foregoing their rights in the face of minor infractions, so that the state is not overwhelmed by an impossible number of complaints, and justice can continue to be effectively administered.Footnote ⁸²

In addition to these precepts, there is another aspect of the human instinct of sociability that Aquinas does not mention, but which is every bit as important as the requirement to observe justice. This is the willingness of all citizens to trust one another sufficiently to enter into economic agreements and relationships, for example contracts of employment. For a great many common goods within a community depend at least to some extent on private economic activity. Goods such as health care and education, road building and communications, even where state-funded, arise from voluntary transactions, which cannot exist without ordinary trust between persons.Footnote ⁸³ Civil remedies testify to the importance of this kind of economic activity, for acts that disrupt or threaten social peace are not limited to matters covered by the state criminal law. The character of this trust is anchored in each person's internalisation of the virtue of justice, the steady disposition to act according to justice's precepts without coercion.

Thus far, these conclusions are available to any reasonable person who takes the time and care to reflect upon the basic needs of society. But for Aquinas these natural laws are not the only sources of just rules and civic peace. For in addition to lawful obligations of peace and justice there are also the specifically Christian moral obligations of neighbourly love. Natural law directs every person to deal justly with others, by rendering to each person what is owed, and by refraining from that which is theirs.Footnote ⁸⁴ As a kind of ius, natural law promotes peace by restoring or repairing the just situation between individuals. In so doing it calls upon the virtues, principally justice and prudence, to direct our actions to the correct ends. The theological virtue of charity [caritas] is concerned with the requirement to love neighbours and enemies even extending beyond justice. For charity requires (a) the necessity of wishing for, and where possible assisting in bringing about, eternal good to one's enemies as their ultimate end; (b) the excellence of wishing for, and if possible assisting in, temporal flourishing for one's enemies, and the necessity of not wishing for or conspiring to bring about their ruin; and (c) the forgiveness of wrongs for which it would not be contrary to justice to seek redress.Footnote ⁸⁵ Charity is not thereby contrary to justice, for it infuses all of the natural virtues by directing their works to the highest end of friendship with God: it is the mover, form and end of every virtue.Footnote ⁸⁶ It transforms temporal justice into supernatural justice.

Christian charity not only demands suitable inward states (such as avoidance of anger, peaceful intentions toward others, etc) but also the performance of outward acts.Footnote ⁸⁷ It involves giving the benefit of doubt to others, being ready to forgive, as well as the courage to oppose injustices even when one is not personally affected by them. It is charity also that causes one to risk one's life in order to save another. These instances of charity are not supererogatory, additional precepts, but counsels of perfection, i.e. intimations of what must be done in order to perfect one's (already due) lawful duties.Footnote ⁸⁸ They represent a deepening experience of natural human inclinations of sociability.

IV. Exceptionless Norms

Having pinpointed some natural laws that flow from human sociability, it is necessary to ask whether such norms hold in all cases, or are otherwise perennial features of a political community, and to defend them (briefly) from an attack on the very possibility of such norms. It will be instructive to begin with Aristotle.

Aristotle famously defines right actions (and right dispositions) by reference to a mean, so that e.g. courage exists between cowardice on the one hand, and recklessness on the other. But he goes on to say that:

Such terms identify minimum moral rules; the acts they mention are not limited to those Aristotle mentions in this passage, for there are ‘[other] acts that a man cannot be compelled to do, and rather than do them he ought to submit to the most terrible death’: acts including, for example, matricide.Footnote ⁹⁰ Augustine and Aquinas pinpoint the invariant element that causes such actions to be wrong in any circumstance: such acts (as e.g. debauchery or blasphemy) can never be done with a good will;Footnote ⁹¹ negative precepts of this kind bind forever and always [semper et ad semper] by reason of their objects (i.e. aim).Footnote ⁹² They are evil in themselves [mala ex genere] and cannot be good no matter where or how performed; the most that can be said is that generically good or bad acts can gain additional good or evil from the circumstances in which they are performed.Footnote ⁹³ So it is by reason of its object that, for example, Aquinas says that ‘every theft is a sin.’Footnote ⁹⁴

The class of exceptionless moral norms must be delineated with care; for Aquinas's general teaching (to which such norms represent an exception) is that the more one descends into detail, the more one will discover exceptions to the general precept.Footnote ⁹⁵ This applies in particular to positive obligations, such as that one must return to one's neighbour what belongs to them: this rule applies ‘forever but not always’ [semper sed non ad semper],Footnote ⁹⁶ i.e. not on every occasion; for it may be that one's children are starving whilst one's neighbour has plenty.

If we turn to the norms of sociability, we find this distinction being observed. There is first of all the obligation to seek peace (even through war), an obligation that holds ‘forever but not always’. Just as there can be no justice without (some) peace, there cannot be peace without (some) justice. Hence there are certain negative precepts that hold without exception, forever and always: for example, that one must not kill the innocent, or that one must not lie.Footnote ⁹⁷ Encompassing these duties is the requirement mentioned by Aquinas at ST I-II.94.2c, to avoid committing offences against those with whom we ought to live in peace: a requirement that additionally involves desisting from contention (spreading lies or denying truth),Footnote ⁹⁸ fighting [rixa]Footnote ⁹⁹ and other matters of criminal liability. These norms constitute the foundation of peace and justice in the state: they are a necessary but not sufficient part of what makes human actions sociable, civilised and lawful. They represent the natural law content of positive law: the body of laws that is otherwise constituted by broader determinations of moral considerations according to the circumstances and times in which they are instituted, and which are, at the limit, legally binding through the force of their enactment alone.Footnote ¹⁰⁰

Throughout the history of philosophy, there have been strident objections to the idea of natural laws of justice and sociability. Here, two such attacks may be singled out: that of Hume's knave, and (perhaps the archetype of all such figures) Plato's Callicles in the Gorgias. Both are, in a sense, anti-social philosophies: they strike at the heart of the conceptions of sociability outlined above. For Hume's knave,

According to one reading, it is significant for the knave that he recognises the general goodness of the norms that, from time to time, he seeks to evade. The goodness of such norms (for example the norm against lying) reaches down into conceptions of exceptionless human goods, such as knowing and avoiding ignorance and error.Footnote ¹⁰² Such goods are objects of human striving, and figure in human reasoning and action in virtue of human nature. They are therefore understood as perfecting human nature, by removing what is harmful to it:Footnote ¹⁰³ avoidance of acting on mistakes, of being misled or led into doubt or error. The knave as much as anyone benefits from and understands the value of, honesty. The ‘exceptions’ which the knave detects pertain to the acquisition of false goods (wealth, position, office), but damage the real goods of social concord and civic friendship. A society containing liars suffers from the distrust of its politicians and office-holders, and of its media and, by and large, its fellow citizens. Nor does the knave revel in being a knave: for (as Aristotle in effect observed) the knave cannot ignore the lack of congruence between his actions and the just, honest and benevolent actions that he for the most part observes and values.Footnote ¹⁰⁴ Such a person is ‘not disposed in a friendly way even to himself.’

However, on a different reading, honesty is only a policy for the knave, valued only because it for the most part advances the knave's (and everyone's) fortunes. But if so, the knave is radically mistaken about the human goods and values that such a policy advances: in particular, he is blinded to the possibility of genuine friendship, which involves a sharing in the value of truth. For ‘friendship in the primary and real sense [is] the friendship of good people insofar as they are good, while the rest will be friendships by being like it…’Footnote ¹⁰⁵ A reply to the knave therefore stresses the inadequacy of the range of (false) goods that the knave values, and condemns, as destroying or obscuring genuine goods, his sowing the seeds of distrust in the community. Indeed, Hume regards the knave as sensible ‘according to the imperfect way in which human affairs are conducted’: he is a knave amongst knaves, recalling Augustine's warning that the worse the objects of love, the worse is the agreement to share them. Thus the knave may not be inconsistent in his immoralism, but is nevertheless impoverished by his failure to grasp genuine human values, the greatest of which is again, friendship.

The archetype of this immoralist, differing from the knave only by openly despising the good, is Plato's Callicles. Callicles resists Socrates's arguments (that it is better to suffer wrong than to do it) to the bitter end. His retorts have little to do with the argument, but simply do not take it very seriously.Footnote ¹⁰⁶ Though he feels the force of Socrates's assertions, he refuses to submit to them: ‘I do not know why, but you seem to make sense to me, Socrates. Yet I suffer the affection of the multitude: I am not entirely convinced.’Footnote ¹⁰⁷ Socrates's reply aptly pinpoints the difficulty: ‘It is the demotic love residing in your heart that resists me, Callicles. If we argued the issues over and over again, you would be persuaded.’Footnote ¹⁰⁸

Honest arguments are a kind of friendship insofar as they are constituents of a common good: a sharing of truth and (sometimes) of moral instruction.Footnote ¹⁰⁹ One who fails to be moved by the rational force of arguments is enslaved by error; for such a person to think themselves happy is to sink deeper into untruth.Footnote ¹¹⁰ Moral philosophers need frankly to confront the limited power of arguments in moving unreasonable people to the good. For prudence cannot operate correctly without the assistance of the other virtues: temperance, justice, fortitude etc. Hence Callicles is precisely that type of young man (immature in attitudes if not in years) that Aristotle has in mind when saying that some are not fitted to listen to arguments about morality (‘political science’).Footnote ¹¹¹

The absolute (exceptionless) norms of natural law are never entirely erased from the mind: the foundational precepts of natural law even enter into the reasoning of the damned, who do not act according to them.Footnote ¹¹² For all human beings possess synderesis, the natural disposition whereby they do not fall utterly into error as regards the most basic practical precepts.Footnote ¹¹³ It is for this reason that it is worthwhile to have the argument ‘over and over again’ with such persons, who are not devoid of all reason.

V. Closing Remarks

Just as there are invariant, unchanging aspects of the human condition, so also there are exceptionless moral norms of natural law that provide avenues to human fulfilment. Many such norms are not controversial, at least to those intelligent and reasonable enough to understand human affairs, for they are not directed to any specific ‘form of of the good’. Rather they are essential constituents in any effort to secure the good. Apart from sheer irrationalists such as a Callicles, or a Thrasymachus, it is evident that they are not mere steps on the way to some good, but are at the same time good in themselves. So far from realising this is Callicles that he thinks the person who restrains himself from committing pleonexia is better off dead.Footnote ¹¹⁴

Callicles's contention, that it is only by convention (nomos) and not by nature (physis) that it is more shameful to commit injustice than to suffer it,Footnote ¹¹⁵ overlooks the possibility that ‘nature’ is itself normative, a source of natural laws. Such a possibility begins with the ability to identify universal human goods, not the least of which is the ordinary civic friendship and lack of violent assault that enable Callicles to speak his mind unmolested. The brutality of his sentiments belies the peaceful (friendly) forms of behaviour that are essential to the discussion in which he is a participant. These forms are not merely conventions, but are also natural foundations of human affairs. They are part of those natural laws that allow for the pursuit of further human goods, such as knowledge (in this case). Above all, Callicles is blinded to the natural law content of conventional, positive law: the body of moral rules and precepts confirmed in many or all of the legal systems observed around the world.