THE PRINCIPLES OF NATURAL LAW



PART I.



GENERAL PRINCIPLES OF RIGHT.



CHAP. I.



Of the Nature of Man, considered with regard to Right; of the Understanding, 

and whatever is relative to this faculty.



I. MY design is to inquire into those rules, which nature alone prescribes 

to man, in order to conduct him safely to the end, which every one has, and 

indeed ought to have, in view, namely, true and solid happiness. The system 

or assemblage of these rules, considered as so many laws, imposed by God on 

man, is generally distinguished by the name of Natural Law. This science 

includes the most important principles of morality, jurisprudence, and 

politics; that is, whatever is most interesting in respect as well to man, 

as to society. There can be nothing therefore more deserving of the 

application of a rational being, of a being, that has its perfection and 

felicity seriously at heart A just knowledge of the maxims, we ought to 

follow in the course of life, is the principal object of wisdom; and virtue 

consists in putting them constantly in practice, without being ever diverted 

from so noble a pursuit. 



II. The idea of right, and much more that of natural right, is undoubtedly 

relative to the nature of man. It is from this nature therefore, from the 

constitution and state of man, that we are to deduce the principles of this 

science.



The word right (droit)[1] in its original signification, comes from the verb 

dirigo, which implies to conduct a person to some certain end by the 

shortest road. Right therefore, in its proper and most general sense, and 

that, to which all the others must be reduced, is whatever directs, or is 

properly directed. This being premised, the first thing we have to examine 

is whether man is susceptible of direction and rule in respect to his 

actions. That we may attempt this with a greater probability of success, we 

are to trace matters to their very origin, and ascending as high, as the 

nature and constitution of man, we must there unravel the principle of his 

actions, and the several states, that properly belong to him, in order to 

demonstrate afterwards in what manner, and how far, he is susceptible of 

direction in his conduct. This is the only method of knowing what is right, 

and what is not.



III. Man is an animal, endowed with understanding and reason; a being, 

composed of an organized body and a rational soul.



With regard to his body, he is pretty similar to other animals, having the 

same organs, properties, and wants. This is a living body, organized and 

composed of several parts; a body, that moves of itself, and, feeble in the 

commencement, increases gradually in its progress by the help of 

nourishment, till it arrives to a certain period, in which if appears in its 

flower and vigour, whence it insensibly declines to old age, which conducts 

it at length to dissolution. This is the ordinary course of human life, 

unless it happens to be abridged by some malady or accident.



But man, besides the marvellous disposition of his body, has likewise a 

rational soul, which eminently discriminates him from brutes. It is by this 

noble part of himself that he thinks, and is capable of forming just ideas 

of the different objects, that occur to him; of comparing them together; of 

inferring from known principles unknown truths; of passing a solid judgment 

on the mutual fitness or agreement of things, as well as on the relations 

they bear to us; of deliberating on what is proper or improper to be done; 

and of determining consequently to act one way or other. The mind recollects 

what is past, joins it with the present, and extends its views to futurity. 

It is capable of penetrating into the causes, progress, and consequences of 

things, and of discovering, as it were at one glance, the intire course of 

life, which enables it to lay in a store of such things, as are necessary 

for making a happy career. Besides, in all this, it is not subject to a 

constant series of uniform and invariable operations, but finds itself at 

liberty to act or not to act, to suspend its actions and motions, to direct 

and manage them as it thinks proper.



IV. Such is the general idea, we are to form of the nature of man. What 

results from it is, that there are several sorts of human actions; some are 

purely spiritual, as to think, to reflect, to doubt, &c. others are merely 

corporeal, as to breathe, to grow. &c. and some there are that may be called 

mixt, in which the soul and body have both a share, being produced by their 

joint concurrence, in consequence of the union, which God has established 

between these two constituent parts of man; such as to speak, to work, &c. 



Those actions, which either in their origin or direction depend on the soul, 

are called human or voluntary; all the rest are termed merely physical. The 

soul is therefore the principle of human actions; and these actions cannot 

be the object of rule, but inasmuch as they are produced and directed by 

those noble faculties, with which man has been enriched by his Creator. 

Hence it is necessary to enter into a particular inquiry concerning this 

subject, and to examine closely into the faculties and operations of the 

soul, in order to discover in what manner they concur to the production of 

human actions. This will help us, at the same time, to unfold the nature of 

these actions, to assure ourselves whether they are really susceptible of 

rule, and how far they are subject to human command.



V. Let man reflect but ever so little on himself, sense and experience will 

soon inform him, that his soul is an agent, whose activity displays itself 

by a series of different operations, which having been distinguished by 

separate names, are likewise attributed to different faculties. The chief of 

these faculties are the understanding, will, and liberty. The soul is indeed 

a simple being; but this does not hinder us, when we attend to its different 

ways of operating, from considering it as a subject, in which different 

powers of acting reside, and from giving different denominations to these 

powers. If we consider the thing in this manner, we shall find it will give 

a greater exactness and perspicuity to our ideas. Let us remember therefore, 

that these faculties are nothing else, but the different powers of acting 

inherent in the mind, by means of which it performs all its operations.



VI. The principal faculty of the soul, that which constitutes the 

fundamental part of its being, and serves, as it were, for its intrinsic 

light, is the understanding. We may define it that faculty or power, by 

which the mind perceives, and forms ideas of things, in order to come at the 

knowledge of truth. Truth may be taken here in two significations; either 

for the nature, state, and mutual relations of things; or for the ideas 

agreeable to this nature, state, and relations. To have a knowledge 

therefore of truth is to perceive things such, as they are in themselves, 

and to form ideas concerning them conformable to their nature.



VII. We must therefore set out with acknowledging, as a fixt and 

incontestable principle, that the human understanding is naturally right, 

and has within itself a strength sufficient to arrive at the knowledge of 

truth, and to distinguish it from error; especially in things, wherein our 

respective duties are concerned, and which are requisite to form man for a 

virtuous, honorable, and quiet life; provided, however, he employs all the 

care and attention, that lies in his power.



Sense and experience concur to convince us of the truth of this principle; 

which is the hinge, as it were, whereon the whole system of humanity turns. 

It cannot be called in question, without sapping the foundation, and 

intirely subverting the whole structure of society; because this would be 

annulling all manner of distinction between truth and error, and between 

good and evil; and, by a natural consequence of this subversion, we should 

find ourselves reduced to the necessity of doubting of every thing; which is 

the highest pitch of human extravagance.



Those who pretend, that reason and its faculties are depraved in such a 

manner, as to be no longer capable of serving as a sure and faithful guide 

to man, either in respect to his duties, or particularly with regard to 

religion, do not reflect, that they have adopted for the basis of their 

system, a principle destructive of all truth, and consequently of religion. 

Thus we see that the sacred scripture, far from establishing any such maxim, 

assures us, that when the Gentiles, which have not the law, do by nature the 

things contained in the law; these, having not the law, are a law to 

themselves. Which shew the work of the law, written in their hearts, their 

conscience also bearing witness.[2]



True it is, that a bad education, vicious habits, and irregular passions, 

may obfuscate the mind; and that neglect, levity, and prejudices, 

precipitate men frequently into the grossest errors in point of religion and 

morals. But this proves only that men may make a bad use of their reason, 

and not that the natural rectitude of the faculties is subverted. What we 

have still to say, concerning this point, will help to set it in a clearer 

light.



VIII. Let us proceed now to a closer inquiry into the operations of the 

understanding. The perception, or view and knowledge of things, is commonly 

formed by the concurrence of two actions; one from the object, and is the 

impression which this object makes on us; the other from the mind, and is 

properly a glance, or simple view of the soul, on the object it is desirous 

of knowing. But, as a first view is not always sufficient, it is necessary, 

that the mind should apply itself for some time to a serious consideration 

of the object, to the end it may acquire a just knowledge of things, and 

form thereof exact ideas. This application, with which the soul continues to 

view the object in order to know it well, is called attention; and, if it 

turns itself different ways, to consider the object on all sides, this is 

termed examen or inquiry. We may therefore affirm, that the perception or 

knowledge of things depends intirely, in respect to the mind, on its natural 

vigor and attention. 



IX. It is by these helps, drawn from his own fund, that man attains at 

length a clear and distinct knowledge of things, and their relations; as 

also of ideas, and the conformity of those ideas to their originals; in 

short, that he acquires the knowledge of truth. We give the name of 

evidence, to this clear and distinct view of things, and of their mutual 

relations; a point to which we should be particularly attentive. For this 

evidence being the essential characteristic of truth, or the sure mark 

whereby one cannot help distinguishing it, the consequence is, that it 

necessarily produces such an internal conviction, as forms the highest 

degree of certainty. It is true that all objects do not present themselves 

with so strong a light, and that notwithstanding the great care and 

application a man may use, all that he is frequently able to attain, is only 

a glimmering light, which, according to its strength or weakness, produces 

different degrees of probability and seeming truth. But this must be 

absolutely the case of every being, whose faculties are limited; it is 

sufficient that man, in respect to his destination and state, is capable of 

knowing with certainty those things which concern his perfection and 

happiness; and moreover, that he is able to distinguish between probability 

and evidence, as also between the different degrees of probability, in order 

to proportion his assent to those differences. Now a person need but enter 

never so little into himself, and reflect on the operations of his mind, to 

be convinced, beyond any possibility of doubt, that man is really possessed 

of this discernment.



X. The senses, taken from the sensitive faculty, the imagination also, and 

the memory, must he all reduced to the understanding. In fact, the senses, 

considered in this manner, are nothing else but the understanding itself, as 

it makes use of the senses and organs of the body, to perceive corporeal 

objects. The imagination likewise is nothing but the understanding, as it 

perceives absent objects, not in themselves, but by their images formed in 

the brain. The memory, in fine, is no more than the understanding, 

considered as possessed of the faculty of retaining the ideas, it forms of 

things, and capable of representing them to itself, whenever there is 

occasion; advantages that principally depend on the care we take in 

repeating frequently those ideas.



XI. From what has been hitherto said with regard to the understanding, it 

follows, that the object of this faculty of the soul is truth, with all the 

acts and means, that lead us to it. Upon this supposition, the perfection of 

the understanding consists in the knowledge of truth, this being the end, 

for which it is designed.



There are two things, among others, opposite to this perfection, ignorance 

and error, which are two maladies, as it were, of the mind. Ignorance is no 

more than a privation of ideas or knowledge; but error is a nonconformity or 

opposition of our ideas to the nature and state of things. Error being 

therefore the subversion of truth, is much more opposite to it, than 

ignorance, which is a kind of medium between truth and error.



It is to be observed here, that we do not speak of the understanding, truth, 

ignorance, and error, purely to know what these things are in themselves; 

our main design is to consider them as principles of our actions. In this 

light ignorance and error, though naturally distinct from one another, are 

generally mixt, as it were, and confounded; insomuch, that whatever is said 

of one ought equally to be applied to the other. Ignorance is frequently the 

cause of error; but whether joined or separate, they follow the same rules, 

and produce the same effect by the influence, they have over our actions or 

omissions. Perhaps, were we to examine into things exactly, error only, 

properly speaking, can be looked upon as a principle of action, and not 

simple ignorance, which, being nothing more of itself than a privation of 

ideas, cannot be productive of any thing.



XII. There are several sorts of ignorance, and error, whose different 

divisions it is proper for us to observe. 1. Error, considered in respect to 

its object, is either of the law or of the fact. 2. With regard to its 

origin, ignorance is voluntary or involuntary, error is vincible or 

invincible. 3. In relation to the influence of the error on a particular 

affair or action, it is esteemed essential or accidental.



Error is of the law or fact according as people are mistaken either in 

respect to the disposition of the law, or in regard to a fact, that is not 

sufficiently known. For instance, it would be an error of the law, were a 

prince to suppose himself intitled to declare war against a neighbouring 

state, only because it insensibly increases in strength and power. Such was 

likewise the error so common formerly among the Greeks and Romans, that it 

was allowable for parents to expose their children. On the contrary, the 

idea Abimelech had of Sarah, the wife of Abraham, by taking her for an 

unmarried person, was an error of the fact.[3]



The ignorance a person lies under through his own fault, or an error, 

contracted by neglect, and which might have been avoided by using all 

possible care and attention, is a voluntary ignorance, or a vincible and 

surmountable error. Thus the polytheism of the Pagans was a vincible error; 

for they had only to make a right use of their reason, in order to be 

convinced, that there was no necessity for supposing a plurality of gods. 

The same may be said of an opinion, established among most of the ancients, 

that piracy was lawful against those, with whom there was no treaty 

subsisting, and that it was allowable to consider them as enemies. Ignorance 

is involuntary, and error invincible, when they are such as could neither 

have been prevented nor removed, even by all the care and endeavours, that 

are morally possible; that is, judging of them according to the constitution 

of human things, and of common life. Thus the ignorance of the Christian 

religion, under which the people of America labored, before they had any 

communication with the Europeans, was an involuntary and invincible 

ignorance.



In fine we understand by an essential error, that, whose object is some 

necessary circumstance in the affair, and which for this very reason has a 

direct influence on the action, done in consequence thereof; insomuch, that, 

were it not for this error, the action would never have been done. Hence 

this is denominated likewise an efficacious error. By necessary 

circumstances, we are to understand those, which are necessarily required, 

either by the very nature of the thing, or by the intention of the agent, 

formed at the proper time, and made known by suitable indications. It was 

thus, for instance, an essential error in the Trojans, at the taking of 

their town, to shoot their darts against their own people, mistaking them 

for enemies, because of their being armed after the Greek manner. Again; a 

person marries another man's wife, supposing her to be a maid, or not 

knowing that her husband is still living; this regards the very nature of 

the thing, and is of course an essential error. 



On the contrary an accidental error is that, which has no necessary 

connexion of itself with the affair, and consequently cannot be considered, 

as the real cause of the action. A person abuses or insults another, taking 

him for somebody else, or because he supposes the prince is dead, as it had 

been groundlessly reported, &c. These are errors merely accidental, which 

subsist indeed in the mind of the agent, and have accompanied him in the 

action, but cannot be considered, as its real cause.



It is likewise observable, that these different qualities of ignorance or 

error may concur, and may be found united in the same case. It is thus an 

error of the fact may be either essential or accidental; and both the one 

and the other may be either voluntary, or involuntary; vincible or 

invincible. So much may suffice for what regards the understanding. Let us 

proceed now to examine into the other faculties of the soul, which concur 

also to the production of human actions.







1. The etymology given here by the author was intended only for the French 

word Droit.



2. Rom, ii. 14, 15.



3. See another example in St. Matthew, chap. xv. 4, 5.