Self-Interest

To discover these necessities and interests, we must consider the same qualities of human nature, which lead to the laws of society.
Men are naturally selfish or only have a confined generosity.
    They are not easily induced to perform any action for the interest of strangers, except with a view to some reciprocal advantage.
    They hope to obtain this advantage only by such a performance.
These mutual performances cannot be finished at the same instant.
    One party must be contented to:
        remain in uncertainty, and
        depend on the gratitude of the other for a return of kindness.
But there is so much corruption among men that this becomes but a slender security.
    The benefactor here is supposed to bestow his favours with a view to self-interest.
    This takes off from the obligation and sets an example to selfishness.
If we follow the natural course of our passions and inclinations, we should perform but few actions for the advantage of others, from disinterested views.
    Because we are naturally very limited in our kindness and affection.
    We should perform as few of that kind, out of a regard to interest.
        Because we cannot depend on their gratitude.
The mutual commerce of good offices is lost among mankind.
    Every one is reduced to his own skill and industry for his well-being and subsistence.
The invention of the law of nature, concerning the stability of possession, has already rendered men tolerable to each other.
    The transference of property by consent has begun to render them mutually advantageous.
    But still these laws of nature are not sufficient to render them so serviceable to each other, as nature has fitted them to become.
Though possession is stable, men may often reap but small advantage from it, while they:
    have more goods than they need, and
    suffer by the want for others.
The transference of property is the proper remedy for this inconvenience.
    But it cannot remedy this entirely.
        Because it can only take place with regard to objects that are present and individual, not to objects that are absent or general.
    One cannot transfer the property of a particular house, 20 leagues distant.
        Because the consent cannot be attended with delivery.
    One cannot transfer the property of 10 bushels of corn, or five hogsheads of wine, by the mere expression and consent.
        Because these:
            are only general terms, and
            have no direct relation to any particular heap of corn or barrels of wine.
Besides, commerce is not confined to the barter of commodities.
    It may extend to services and actions, which we may exchange to our mutual interest and advantage.
    Your corn is ripe today.
        Mine will be ripe tomorrow.
    It is profitable for us both:
        that I should labour with you today, and
        that you should aid me tomorrow. 
    I have no kindness for you and know you have as little kindness for me.
    Therefore, I will not take any pains on your account.
    Should I labour with you on my own account expecting a return, I know that I should:
        be disappointed, and
        depend on your gratitude in vain.
    Here then I leave you to labour alone.
    You treat me in the same manner.
    The seasons change.
    Both of us lose our harvests for lack of mutual confidence and security.

All this is the effect of the natural and inherent principles and passions of human nature.
These passions and principles are inalterable.
    Our conduct, which depends on them, must be inalterable too.
It would be in vain for moralists or politicians to:
    tamper with us, or
    attempt to change our usual actions, with a view to public interest.
If the success of their designs depend on their success in correcting men's selfishness and ingratitude, they would never make any progress unless aided by omnipotence.
    Omnipotence would alone be able to:
        re-mould the human mind, and
        change its character in such fundamental articles.
Moralists and politicians can only pretend to:
    give a new direction to those natural passions, and
    teach us that we can satisfy our appetites better in an oblique and artificial manner, than through their headlong and impetuous motion.
Hence I learn to do a service to another, without bearing him any real kindness.
    Because I forsee that he will return my service:
        in expectation of another of the same kind, and
        to maintain the same correspondence of good offices with me or others.
    After I have served him and he has gained the advantage from it, he is induced to perform his part, as foreseeing the consequences of his refusal.

This self-interested commerce begins to take place and predominates in society.
    But it does not entirely abolish the more generous and noble intercourse of friendship and good offices.
I can still do services to persons I love and know, without any prospect of advantage.
    They may make me a return in the same way, with just the view of recompensing my past services.
To distinguish the interested commerce from the disinterested one, the interested commerce is called a promise.
    A promise is the sanction of the interested commerce of mankind.
    When a man promises anything, he expresses a resolution to perform it.
    By using the word 'promise', he subjects himself to the penalty of never being trusted again in case of failure.
A resolution is the natural act of the mind.
    But if there were only a resolve, promises would:
        only declare our former motives, and
        not create any new motive or obligation.
Conventions of men create a new motive.
    Experience teaches us that human affairs would be more mutual advantageous if there were certain symbols instituted.
    These symbols might give each other the security of our conduct in any particular incident.
    After these signs are instituted, whoever uses them is immediately bound by his interest to execute his engagements.
        He must never expect to be trusted anymore, if he refuses to perform what he promised.