Of the Law of Nature in general
That Man, who has thoroughly examined the Nature and Disposition of Mankind, may plainly understand what the Law Natural is, the Necessity thereof, and which are the Precepts it proposes and enjoyns to Mankind. For, as it much conduces to him who would know exactly the Polity of any Community, that he first well understand the Condition thereof, and the Manners and Humours of the Members who constitute it: So to him who has well studied the common Nature and Condition of Man, it will be easie to discover those Laws which are necessary for the Safety and common Benefit of Mankind.
This then Man has in common with all the Animals, who have a Sense of their own Beings; that he accounts nothing dearer than Himself; that he studies all manner of ways his own Preservation; and that he endeavours to procure to himself such things as seem good for him, and to avoid and keep off those that are mischievous. And this Desire of Self-Preservation regularly is so strong, that all our other Appetites and Passions give way to it. So that whensoever an Attempt is made upon the Life of any man, though he escape the danger threatned, yet he usually resents it so, as to retain a Hatred still, and a desire of Revenge on the Aggressor.
Society absolutely necessary.
But in one particular, Man seems to be set in a worse condition than that of Brutes, that hardly any other Animal comes into the world in so great weakness; so that ’twould be a kind of Miracle, if any man should arrive at a mature Age, without the aid of some body else. For even now, after so many helps found out for the Necessities of Human Life; yet a many Years careful Study is required before a Man shall be able of himself to get Food and Raiment. *Let us suppose a Man come to his full Strength without any oversight or instruction from other Men; suppose him to have no manner of Knowledge but what springs of it self from his own natural Wit; and thus to be placed in some Solitude, destitute of any Help or Society of all Mankind beside. Certainly a more miserable Creature cannot be imagined. He is no better than dumb, naked, and has nothing left him but Herbs and Roots to pluck, and the wild Fruits to gather; to quench his thirst at the next Spring, River, or Ditch; and to shelter himself from the Injuries of the Weather, by creeping into some Cave, or covering himself after any sort with Moss or Grass; to pass away his tedious life in Idleness; to start at every Noise, and be afraid at the sight of any other Animal; in a Word, at last to perish either by Hunger, or Cold, or some wild Beast. It must then follow, that whatsoever Advantages  accompany Human Life, are all owing to that mutual Help Men afford one another. So that, next to Divine Providence, there is nothing in the world more beneficial to Mankind than Men themselves.
And yet, as useful as this Creature is, or may be, to others of its kind, it has many Faults, and is capable of being equally noxious; which renders mutual Society between Man and Man not a little dangerous, and makes great Caution necessary to be used therein, lest Mischief accrue from it instead of Good. In the first place, a stronger Proclivity to injure another is observ’d to be generally in Man, than in any of the Brutes; for they seldom grow outragious, but through Hunger or Lust, both which Appetites are satisfi’d without much Pains; and that done, they are not apt to grow furious, or to hurt their Fellow-Creatures, without some Provocation. Whereas Man is an Animal always prone to Lust, by which he is much more frequently instigated, than seems to be necessary to the Conservation of his Kind. His Stomach also is not only to be satisfied, but to be pleased; and it often desires more than Nature can well digest. As for Raiment, Nature has taken Care of the rest of the Creatures that they don’t want any: But Men require not only such as will answer their Necessity, but their Pride and Ostentation. Beside these, there are many Passions and Appetites unknown to the Brutes, which are yet to be found in Mankind; as, an unreasonable Desire of possessing much more than is necessary, an earnest pursuit after Glory and Pre-eminence; Envy, Emulation, and Outgoings of Wit. A Proof hereof is, that most of the Wars with which Mankind is harrass’d, are raised for Causes altogether unknown to the Brutes. Now all these are able to provoke Men to hurt one another, and they frequently do so. Hereto may be added the great Arrogance that is in many Men, and Desire of insulting over others, which cannot but exasperate even those who are naturally meek enough; and from a Care of preserving themselves and their Liberty, excite them to make Resistance. Sometimes also Want sets Men together by the Ears,9 or because that Store of Necessaries which they have at present seems not sufficient for their Needs or Appetites.
Moreover, Men are more able to do one another Harm than Brutes are. For tho’ they don’t look formidable with Teeth, Claws, or Horns, as many of them do; yet the Activity of their Hands renders them very effectual Instruments of Mischief; and then the Quickness of their Wit gives them Craft, and a Capacity of attempting that by Treachery which cannot be done by open Force. So that ’tis very easie for one Man to bring upon another the greatest of all Natural Evils, to wit, Death itself.
Beside all this, it is to be consider’d, that among Men there is a vast Diversity of Dispositions, which is not to be found among Brutes; for among Brutes, all of the same Kind have the like Inclinations, and are led by the same inward Motions and Appetites: Whereas among Men, there are so many Minds as there are Heads, and every one has his singular Opinion; nor are they all acted with simple and uniform Desires, but with such as are manifold and variously mix together. Nay, one and the same Man shall be often seen to differ from himself, and to desire that at one Time which at another he extremely abhorred. Nor is the Variety less discernible, which is now to be found in the almost infinite Ways of living, of directing our Studies, or Course of Life, and our Methods of making use of our Wits. Now, that by Occasion hereof Men may not dash against one another, there is need of wise Limitations and careful Management.
So then Man is an Animal very desirous of his own Preservation; of himself liable to many Wants; unable to Support himself without the Help of other of his Kind; and yet wonderfully fit in Society to promote a common Good: But then he is malicious, insolent, and easily provoked, and not less prone to do Mischief to his Fellow than he is capable of effecting it. Whence this must be inferred, that in order to his Preservation, ’tis absolutely necessary, that he be sociable,10 that is, that he join with those  of his Kind, and that he so behave himself towards them, that they may have no justifiable Cause to do him Harm, but rather to promote and secure to him all his Interests.
The Rules then of this Fellowship, which are the Laws of Human Society, whereby Men are directed how to render themselves useful Members thereof, and without which it falls to pieces, are called the Laws of Nature.
From What has been said, it appears, that this is a11 fundamental Law of Nature, That every man ought, as much as in him lies, to preserve and promote Society: That is, the Welfare of Mankind. *And since he that designs the End, cannot but be supposed to design those Means without which the End cannot be obtain’d, it follows that all such Actions as tend generally and are absolutely necessary to the Preservation of this Society, are commanded by the Law of Nature; as, on the contrary, those that disturb and dissolve it are forbidden by the same. All other Precepts are to be accounted only Subsumptions, or Consequences upon this Universal Law, the Evidence whereof is made out by that Natural Light which is engrafted in Mankind.
God and Providence
Now though these Rules do plainly contain in themselves that which is for the general Good; yet that the same may obtain the Force of Laws, it must necessarily be presupposed, that there is a God, who governs all Things by his Providence, and that He has enjoyed us Mortals, to observe these Dictates of our Reason as Laws, promulgated by him to us by the powerful Mediation of that Light which is born with us. Otherwise we might perhaps pay some obedience to them in contemplation of their Utility, so as we observe the Directions of Physicians in regard to  our Health, *but not as Laws, to the Constitution of which a Superior is necessary to be supposed, and that such a one as has actually undertaken the Government of the other.12
God the Author of the Law of Nature
But, that God is the Author of the Law of Nature, is thus demonstrated (considering Mankind only in its present State, without enquiring whether the first Condition of us Mortals was different from this, nor how the Change was wrought.) Whereas our Nature is so framed, that Mankind cannot be preserved without a sociable Life, and whereas it is plain that the Mind of Man is capable of all those Notions which are subservient to this purpose; and it is also manifest, that Men not only, like the other Creatures, owe their Original to God, but that He governs them, (let their Condition be as it will) by the Wisdom of his Providence. Hence it follows, that it must be supposed to be the Will of God, that Man should make use of those Faculties with which he is peculiarly endow’d beyond the Brutes, to the Preservation of his own Nature: and consequently, that the Life of Man should be different from the lawless Life of the Irrational Creatures. And since this cannot otherwise be atchieved, but by an Observance of the Law Natural, it must be understood, that there is from God an obligation laid upon Man to pay Obedience hereto, as a Means not invented by the Wit, or imposed by the Will of Men, nor capable of being changed by their Humours and Inclinations; but expressly ordain’d by God himself in order to the accomplishing this End. For he that obliges us to pursue such an End, must be thought to oblige us to make use of those Means which  are necessary to the attainment thereof. And that the Social Life is positively enjoined by God upon Men, this is a Proof, that in no other Animal is to be found any Sense of Religion or Fear of a Deity, which seems not so much as to fall within the Understanding of the ungovernable Brute; and yet it has the power to excite in the minds of Men, not altogether profligate, the tenderest Sense; by which they are convinced, that by sinning against this Law Natural, they offend him who is Lord of the Soul of Man, and who is to be fear’d, even where we are secure of any Punishment from our Fellow-Creatures.
Though it be usually said, that we have the Knowledge of this Law from Nature it self, yet this is not so to be taken, as if there were implanted in the Minds of Men just new born, plain and distinct Notions concerning what is to be done or avoided. But Nature is said thus to teach us, *partly because the Knowledge of this Law may be attain’d by the help of the Light of Reason; and partly because the general and most useful Points thereof are so plain and clear, that they at first sight force the Assent, and get such root in the minds of Men, that nothing can eradicate them afterwards; let wicked Men take never so much pains to blunt the edge and stupifie themselves against the Stings of their Consciences. And in this Sense we find in Holy Scripture, that this Law is said to be written in the hearts of Men.Rom. ii. So that having from our Childhood had a Sense hereof instill’d into us, together with other Learning in the usual Methods of Education, and yet not being able to remember the punctual time when first they took hold of our Understanding and possess’d our Minds; we can have no other opinion of our knowledge of this Law; but that it was connate to our Beings, or born together and at the same time with our selves. The Case being the same with every Man in learning his Mother Tongue.
Division of Natural Duties.
Those Duties, which from the Law of Nature are incumbent upon Man, seem most aptly to be divided according to the Objects about which they are conversant. With regard to which they are ranged under three principal Heads; the first of which gives us Directions how by the single Dictates of right Reason Man ought to behave himself towards God; the second contains our Duty towards our selves; and the third that towards other Men. But though those Precepts of the Law Natural, which have a relation to other Men, may primarily and directly be derived from that Sociality, which we have laid down as a Foundation; yet even the Duties also of Man towards God may be *indirectly deduc’d from thence, upon this Account, that the strongest Obligation to mutual Duties between Man and Man arises from Religion and a Fear of the Deity; so as that Man could not become a sociable Creature if he were not imbu’d with Religion; and because Reason alone can go no farther in Religion than as it is useful to promote the common Tranquillity and Sociality or reciprocal Union in this Life: For so far forth as Religion procures the Salvation of Souls, it proceeds from peculiar Divine Revelation. But the Duties a man owes to Himself arise jointly from Religion, and from the Necessity of Society. So that no Man is so Lord of himself, but that there are many things relating to himself, which are not to be disposed altogether according to his Will; partly because of the Obligation he lies under of being a religious Adorer of the Deity, and partly that he may keep himself an useful and beneficial Member of Society.
SOURCE: The Whole Duty of Man According to the Law of Nature (1673)-Samuel von Pufendorf