Law of nature, or natural law; in its most extended sense, refers to certain principles inspired only by nature that are common to men and to animals: on this law are based the union of male and female, the procreation of children and concern for their education, the love of liberty, the conservation of one's own person, and the effort each man makes to defend himself when attacked by others.

But it is an abuse of the term natural law to use it to refer to the impulses that govern the behavior of animals; for they have not the use of reason and are therefore incapable of perceiving any law or justice.

More frequently, we mean by natural law certain rules of justice and equity, which natural reason alone has established among men, or to put it better, which God has engraved in our hearts.

Such are the fundamental precepts of law and of all justice: to live honestly, to offend no one, and to render unto every man what belongs to him. From these general precepts are derived many other particular rules, which nature alone, that is to say reason and equity, suggests to men.

This natural law , based as it is on such essential principles, is perpetual and unvarying: neither law nor custom can contravene it, nor dispense a man from its obligations; in this way it differs from positive law, that is to say those rules which exist only because they were established by formal laws. Since this positive law is subject to alteration by the same authority that established it, private persons may even contravene it by an express agreement, as long as the law does not prohibit it.

Some mistakenly confuse the natural law with the law of peoples: the latter is also composed in part of rules which right reason has established among all men; but it also includes certain practices against the natural order that men have agreed on, war, for example, or different kinds of slavery: whereas the natural law allows nothing but what is consistent with right reason and equity.

The principles of the natural law are thus included in the law of peoples, and especially in that part of it which is oldest; they are also included in public and private law: for the precepts of natural law listed above are the purest source, and the foundation, of the greatest part of both public and private law. But public and private law include other rules based on positive laws. See Law of Nations, Positive Law, Public Law, Private Law.

From these general ideas about natural law , we can conclude that this law , properly speaking, is nothing but the science of social relations, which we call morality .

This science of social relations or of natural law was known only very imperfectly by the ancients; even their sages and philosophers discussed it for the most part only very superficially, intermingling many errors and vices. Pythagoras was the first who undertook to discuss virtue. After him, Socrates did it more exactly and extensively: but he wrote nothing, and was content to instruct his disciples through familiar conversations: nevertheless, he is regarded as the father of moral philosophy. Plato, disciple of Socrates, confined all his teaching on morality to ten dialogues, several of which deal particularly with natural law and politics: such are his treatises on the republic, on the laws, on politics etc. Aristotle, the most famous of Plato's disciples, is the first ancient philosopher who produced a system of morals that was somewhat methodical; but there he deals more with the duties of the citizen than with those of man in general, and with the reciprocal duties of those who are citizens of more than one state.

The best moral treatise that we have from antiquity is the book of duties by Cicero, which contains in summary form the principles of natural law . But many points are missing that could perhaps have been found in his treatise on the republic, of which we have only a few fragments. There are also some good things in his treatise on the laws, where he attempts to prove that there exists a natural law independent of human institutions whose origin is the will of God. He demonstrates that this is the foundation of all just and reasonable laws; he shows the usefulness of religion in civil society, and deduces throughout the reciprocal duties of men.

The principles of natural equity were not unknown to Roman lawyers: some of them even claimed to follow it in preference to the rigor of the law; such, for example, was the sect of the Proculeiani: on the other hand, the Sabiniani adhered more to the letter of the law than to equity. But among what remains to us of the works of these lawyers, nothing is left that expressly treats natural law or the law of peoples.

Even the volumes of Justinian contain nothing but a few definitions and very summary notions of natural law and the law of peoples; what there is can be found in the digest of justice and law and the institutes of natural and civil law, and the law of peoples.

Among modern authors, Melanchthon, in his moral philosophy [morale] , gave a sketch of natural law . Benedict Wincler touches on it also in his principles of law : but he often confuses natural law with positive law.

The celebrated Grotius is the first to have formed a system of natural law , in a treatise entitled on the law of war and peace , divided into three books. The title of this work announces only the subject of the law of peoples; and actually, most of the work concentrates on the law of war: but the principles of natural law are established there, both in the preliminary discourse on the certitude of Law in general, and in the first chapter where, after having explained the organization of the work, the meaning of war, and the different ways in which the term law is understood, he further explains that law , defined as a sure and certain rule, is divided into natural law and arbitrary law. In his view, natural law consists of certain principles of right reason that allow us to understand whether an action is morally honest or dishonest, according to its consonance or dissonance with a reasonable and sociable nature; and that as a consequence, God, who is the author of nature, command or forbids such an action. He examines how many kinds of natural law there are, and how it can be distinguished from certain things which have been given this name improperly. He maintains that neither the instinct common to all animals, nor that which is proper to man, constitutes a natural law properly speaking. Finally he examines how the maxims of natural law can be proved.

The rest of this work primarily concerns the laws of war, and as a result the law of peoples and the science of politics. There are certain sections, however, which may also have a connection with natural law ; such as the matters of a just self-defense, of rights common to all men, of the first acquisition of things, and other means of acquiring them; of paternal power, of marriage, of corps or communities, of the power of rulers over their subjects, and masters over their slaves; of the property of sovereign states, and its alienation; of intestate succession, of promises and contracts; of the oath, and the oaths and promises of sovereigns, of public treaties made by the sovereign himself, or without his consent, of harm caused unjustly and the obligations that result from it; of the law of embassies, of the law of burial, of penalties, and how they are administered.

A short while after the treatise of Grotius appeared, John Selden, a famous English lawyer, constructed a system of all the laws of the Hebrews relating to natural law ; he called it of the law of nature and of peoples among the Hebrews . This work is full of erudition, but lacks order and is written in an obscure style; besides, this author does not deduce natural principles from the light of reason alone; rather, he deduces them from the seven precepts supposedly given to Noah, which are actually quite uncertain in number and based on a most dubious tradition; he is even willing to include the decisions of rabbis, whether or not they are well-founded.

Thomas Hobbes, one of the greatest geniuses of the last century, but unfortunately too prejudiced by the indignation he felt against the spirit of sedition which was then unsettling England, published a treatise on the citizen in Paris in 1642. Here, among other dangerous opinions, he attempts to establish, according to the moral philosophy of Epicurus, that the primary purpose of societies is self-preservation and private utility; from this he concludes that all men have the will, the strength, and the power to injure one another, and that the state of nature is a state of war of all against all; to kings he grants an authority without limits, not only in affairs of state, but also in matters of religion. Lambert Verthuisen, a philosopher from the United Provinces, wrote a dissertation to justify the manner in which natural laws are presented in the treatise on the citizen, but he only did it by abandoning Hobbes' principles in an attempt to interpret them in a favorable sense. Hobbes also published another work entitled leviathan , which states in summary that without peace there is no security in a state; that peace cannot exist without the power to command, nor the power to command without weapons; that weapons are worth nothing if they are not in the hands of one person etc. He overtly maintains that the will of the sovereign defines not only justice or injustice, but also religion; and that no divine revelation can oblige the conscience unless the sovereign, to whom he grants an arbitrary power, gives it the force of law.

Subsequently, Spinoza had the same ideas about the state of nature, which he based on the same principles.

We will not undertake to refute the dangerous system of these two philosophers, whose errors are easily recognized.

Having conceived a plan to construct a system of the law of nature and of peoples , Baron Pufendorf followed the spirit and method of Grotius; he examined the origins of things and profited from the insights of those who had preceded him; he added his own discoveries, and published his first treatise under the title elements of a universal jurisprudence . This work, even though still imperfect, so enhanced the author's reputation that in the following year Charles Louis, elector palatine, summoned him to his university at Heidelberg and created for him a professorial chair of the law of nature and of peoples .

In the preface which preceded his translation of Pufendorf's treatise on the law of nature and of peoples , Monsieur de Barbeyrac mentions another german professor named Buddaeus, who had been professor of natural law and moral philosophy at Halle in Saxony, and who is the author of a history of natural law .

Monsieur Burlamaqui, author of the principles of natural law , who will be discussed shortly, had earlier been professor of natural law and civil law at Geneva; noting this, we remark in passing that several states of Germany and Italy have recognized the usefulness of establishing a public school of natural law and the law of peoples, which is the source of civil, public, and private law ; it would be most desirable if the study of natural law and the law of peoples, and of public law were taken as seriously everywhere: let us return to Pufendorf, whom we left for a moment.

The elements of a universal jurisprudence is not his only work on natural law ; two years

later he published his legal treatise, on the law of nature and of peoples , which was translated by Barbeyrac with accompanying notes; Pufendorf also published an abridgment of this treatise, entitled the duties of man and citizen . Although his large treatise is also entitled on the law of nature and of peoples , it deals much more with the law of peoples than with natural law : an analysis of this work has already been provided under the heading Law of Nations, to which we refer the reader.

The most recent, the most exact, and the most methodical work that we have on natural law is the one we have already mentioned by J.J. Burlamaqui, councillor of state and formerly professor of natural law and civil law. It was printed at Geneva in 1747 and is entitled principles of natural law , divided into two parts.

The subject of the first part is the general principles of law ; of the second the natural laws [les lois naturelles]: each of these parts is divided into several chapters, and each chapter into several paragraphs.

In the first part, which deals with the general principles of law , he first defines natural law , then goes on to locate the principles of this science in the nature and condition of man; he examines different actions, especially those which are the subject of law ; he explains that the understanding seeks truth naturally, that its perfection consists in the knowledge of truth, and that ignorance and error are two stumbling blocks to this knowledge.

From there he moves to the human will, to its instincts, inclinations, passions, and to the use it makes of its freedom in relation to truth and to matters which are self-evident, to good and evil, and to indifferent things.

Man is capable of directing his conduct; he is accountable for his actions, and they can be imputed to him.

The distinction among the different conditions of man is also part of the knowledge of natural law ; it is necessary to consider his earliest condition in relation to God, to society or to isolation, and to peace and war; certain conditions are secondary and adventitious, such as those which result from birth and marriage; for example, the state of weakness which man finds himself in at birth puts children in a condition of natural dependence on their fathers and mothers; the position of man in relation to property and to government are also considered secondary conditions.

It would not be fitting for man to live in the absence of rules: a rule presupposes a purpose; man's purpose is to work toward his own happiness; that is the system of providence; it is a desire essential to man and inseparable from reason, which is the fundamental rule for mankind.

The rules of conduct which derive from this are: to distinguish properly between good things and bad; to understand that true happiness cannot consist in things that are incompatible with the nature and condition of man; to assess present and future in relation to one another; not to seek out a good which entails a greater evil; to put up with a trifling evil when it is followed by a more weighty good; to prefer the most perfect of goods; in certain situations, to make up one's mind on the grounds of possibility alone, or more reasonably, on the grounds of appearances; and finally, to develop a taste for true goods.

For a proper knowledge of natural law , it is necessary to understand what obligation is, conceived in general. Law [le droit] , considered as a power or right [pris en tant que faculté] entails obligation: there are several kinds of rights and obligations; some are natural, some acquired; some are such that they cannot be exploited to the letter, while others can never be renounced: we distinguish among these according to their aim or purpose; for instance, the right to self-determination [le droit que nous avons sur nous-mêmes], which we call freedom ; the right of property in the case of things which belong to us; the right of empire or authority over the persons and actions of others; and finally, the right one might have to things that belong to others, which is also of several kinds.

Since man is by nature a dependent being, he must regulate his actions by the law, which is nothing but a rule prescribed by the sovereign: the true foundations of sovereignty are power, wisdom, and goodness combined. The purpose of the laws is not to constrain freedom, but to guide all men's actions in a suitable manner.

Basically, these are the subjects that Monsieur Burlamaqui considers in the first part of his treatise; in the second, which deals especially with natural laws, [lois naturelles] he defines the natural law [la loi naturelle] as a law that God imposes on all men, which they can discover and understand by the light of reason alone, when they carefully consider their nature and condition.

The natural law [le droit naturel] is the system of these same laws [lois] assembled in a body.

Natural jurisprudence is the art of acquiring the knowledge of these laws of nature [lois de la nature], of developing them, and applying them to human actions.

It is impossible to doubt that there are natural laws [lois naturelles] , since everything conspires to prove to us the existence of God, who, having the right to prescribe laws [lois] to men, regulates their conduct as a consequence of his power, wisdom, and goodness.

The means of discerning what is just or unjust, or what is commanded by the natural law [la loi naturelle], are 1. an instinct, or a kind of internal feeling that inclines us toward certain actions or away from them; 2. reason, which verifies our instinct; it develops principles, and deduces consequences from them; 3. the will of God which, when known to man, becomes his supreme rule.

Man cannot acquire a knowledge of the natural laws [les lois naturelles] unless he examines his nature, his temperament or constitution, and his condition

All the natural laws [les lois naturelles] relate to three objects: God, self, and others.

Religion is the foundation of those which concern God

Love of self [l'amour de soi-même] is the foundation of the natural laws [lois naturelles] which concern ourselves.

The spirit of society is the foundation of those which concern others.

God has sufficiently acquainted men with the natural laws [les lois naturelles]; but men can also help each other to know them. These laws [lois] are the work of God's goodness, and depend on no arbitrary institution; their effect is to oblige all men to follow them; they are perpetual, unchangeable, and permit no dispensation.

To apply the natural laws [les lois naturelles] to actions, or in other words to judge rightly, one must consult one's conscience, which is nothing but reason; and when it is a case of imputing to someone the consequences of an evil action, it is necessary that he have had knowledge of law [loi] and fact, and that he was not constrained to abrogate the natural law [droit naturel] by a greater force. The authority of the natural laws [les lois naturelles] comes from the fact that God is their author; the function of these same laws [lois], or rather, what tends to oblige men to submit to them, is that the observation of these laws makes for the happiness of man and society; reason demonstrates this truth to us, and in fact it is always the case that virtue is of itself the source of an internal satisfaction, just as vice is a source of anxiety and discontent; it is equally certain that virtue brings with it great external advantages, and vice great evils.

But virtue does not always have the happy external effects that it ought to for he who practices it; we often see that the goods and evils of nature and fortune are distributed inequitably, and not according to merit, that the evils of injustice assail both the innocent and the guilty, and that on occasion virtue even attracts persecution.

All of human prudence is not sufficient to remedy these disorders; it is therefore necessary that another concern persuade men to obey the natural laws [les lois naturelles]; that is the immortality of the soul and the belief in a future life, where the sanctions of the natural laws [les lois naturelles], if imperfectly carried out in the present, will be executed, if the divine wisdom finds it appropriate.

In this manner, our author grounds the authority of the natural law [droit naturel] on reason and religion, which are the two great lights given by God to man to guide his conduct.

The announcement at the beginning of the work states that this treatise is only the beginning of a more extensive study, or of a complete system of the law of nature and of peoples [ le droit de la nature et des gens ], which the author proposed to publish, but since his plan has been derailed by other responsibilities and by poor health, he has decided to publish only this first section. While it is an excellent summary of the natural law [droit naturel] , we cannot help but desire that the author finish the great work he has started, so that we can see the material covered to its full extent.

On this subject, one may also consult those remarks of the author of the spirit of the laws which relate to the natural law [droit naturel] .