David Hume is generally seen as a philosophical opponent of Lockean political theory — partly on the basis of his critique of social contract theory and his disavowal of traditional natural law even in its natural rights version (Hume 1985). Be that as it may Hume’s account of the connections among property justice, and social cooperation is a key moment in the development of classical liberal and libertarian thought. Here I focus on Hume’s exposition in Book III («Of Morals») of his A Treatise of Human Nature (2000 ). In a famous passage, Hume says that, compared to all other species of animals, human beings are very poorly endowed by nature with the means to satisfy their natural needs and passions. There are species that have very elaborate needs — such as lions who need to consume large amounts of meat to stay alive — but who also have very elaborate natural means to satisfy these needs, for example, great speed, sharp claws, and powerful jaws. And there are species that have very modest natural means to satisfy their needs — such as sheep who can only ramble along and get their mouths down to the ground — but who have only modest needs, for example for mouthfuls of grass. For species within each of these categories there is a nice fit between their natural needs and their natural means for satisfying those needs. Human beings are the exception. We have elaborate natural needs for food, clothing, shelter, and so on, but few natural powers to provide for them. As Hume puts it, «In man alone, this unnatural conjunction of infirmity, and of necessity, may be observ’d in its greatest perfection” (2000: 312). Human beings can overcome this disadvantage only through cooperative interaction. «’Tis by society alone he is able to supply his defect» (2000: 312).
By «society» Hume has in mind a network of cooperative economic interaction; and, he holds that the existence of such cooperative interaction depends upon people generally complying with, and being expected to comply with, certain principles of justice. However, Hume denies that there is a natural desire to comply with these principles. Our only natural motivations are our selfishness and our limited generosity. And, in their untempered form, both of these are barriers to cooperation. My natural desire to advance my own interests and my natural desire to advance the welfare of my family and friends will dispose me to seek out opportunities to seize the possessions of others that will satisfy my needs or those of my family or friends. Others’ similar dispositions to seize my possessions will be reinforced by their diminished incentive to produce goods for themselves. And their reinforced focus on plundering me will strengthen my own resolve to advance my interests and those of my family and friends by seizing whatever goods others have managed to produce or seize.
The first principle of justice that enables us to escape from this anti-cooperative quagmire and at least achieve peaceful coexistence is «the stability of possessions,» which forbids the seizure of other people’s holdings. General compliance with this principle assures individuals that they will enjoy the fruits of their own labor and that they had better engage in productive labor because the option of seizing the fruits of others’ labor has been ruled out. The anticipation of this compliance enormously increases everyone’s incentive to live by production and not by predation. Still, we can all do better than autarkic co-existence. If each person (or household or nation) labors fruitfully on the material resources immediately at hand, «persons and possessions must often be very ill adjusted» (2000: 330). One person (or household or nation) will produce lots of corn — much more than she (or it) can consume — while another person (or household or nation) will produce lots of herring — much more than she (or it) can consume. We can adjust possessions to persons through voluntary trade. However, our unconstrained self-love and localized benevolence will dispose us to seize the possessions that others have acquired through trade. And our expectation of such seizures will stymie mutually beneficial exchange. What saves us from this anticooperative quagmire is our understanding that we will each be better off if we comply with a second rule — a rule that allows the consensual transfer of possessions and forbids the non-consensual seizure of goods that are acquired through such transfers. Thus, Hume maintains that stability of possession must be supplemented with «the translation of property by consent» (2000: 330).
Still, the rules of the stability of possession and the transference of property «are not sufficient to render [men] as serviceable to each other, as by nature they are fitted to become» (2000: 334). Many mutually beneficial exchanges cannot take place at one point in time because the goods or services to be exchanged will not be available or needed at the same time. Our untempered self-interest and localized benevolence dispose us to try to induce others to deliver goods or services to us today and to evade the payment that we have promised to make next year. And the prospect of such violations of agreements undermines temporally extended trades that would be mutually gainful. This final anti-cooperative quagmire is overcome by the addition of a third rule, «the obligation of promises,» which requires that each agent fulfill her promises or contracts. I will help you harvest your crop in June if and only if I have an assured expectation that you will fulfill your promise to help me with my crop in August.
Although Hume labels these three rules «Laws of Nature,» he denies that they are natural in the sense of springing from our original passions. Instead, action in accord with these Laws of Nature derives from our understanding that our separate and partial ends will best be advanced in a world in which there is general compliance with all three of these rules. Neither moralists nor politicians «give a new direction to those natural passions;» but they can «teach us that we can better satisfy our appetites in an oblique and artificial manner, than by their headlong and impetuous motion» (2000: 334). We each come to value general compliance with these rules because we each come to see that such compliance is conducive to our own good and to the good of those for whom we especially care. For Hume, cooperation does not require «correcting the selfishness and ingratitude of men» (2000: 334). Rather, the principles of justice enable us to live at peace and positively to cooperate to mutual advantage with an enormous range of people who do not share our personal goals. Single acts of justice — such as returning a wallet that another has unknowingly dropped or reciprocally fulfilling a contract — may seem to be contrary to the actor’s (or the public’s) interests. However, this is only if one focuses on the action’s immediate costs.
This momentary ill is amply compensated by the steady prosecution of the rule, and by the peace and order, which establishes society. And even every individual person must find himself a gainer, on ballancing the account; since without justice, society must immediately dissolve, and every one must fall into that savage and solitary condition, which is infinitely worse than the worst situation that can possibly be suppos’d in society. (2000: 319)
Still, for Hume, our motivating sentiments do evolve in a certain way. Through sympathy we acquire an artificial sentiment on behalf of justice and against injustice. This development is necessary because the combination of our natural passions and our understanding may not suffice to engender compliance with the cooperative rules when the circle of people with whom we interact grows larger. «[W]hen society has become numerous, and has encreas’d to a tribe or nation, this interest [in rule compliance] is more remote; nor do men so readily perceive, that disorder and confusion follow upon every breach of these rules, as in a more narrow and contracted society» (2000: 320). Even within an extended social order, one’s self-love and localized benevolence will in fact always be best served by reciprocal compliance with the principles of justice. However, in many particular cases, the damage to one’s interests that will derive from the «disorder and confusion» occasioned by one’s non-compliance will not be readily perceived. Thus, these passions may combine with our shortsightedness to induce counterproductive defections.
Fortunately, this short-sightedness is counterbalanced by sympathy through which we share in everyone else’s «uneasiness» about being subject to unjust conduct (2000: 320-1). This Humean sympathy does not redirect our actions toward the promotion of the interests of distant individuals. Rather, it reinforces our disposition to abide by the principles of justice and sustains our expectation of reciprocal compliance with these norms in more extended social orders. Sympathy adds additional motivational force to our disposition to abide by the norms that facilitate cooperation to mutual advantage. Ultimately, it is this facilitation of cooperation to mutual advantage that recommends these rules to us.
In The Wealth of Nations (1776) (Smith 1981), Adam Smith echoes Hume’s point that human beings especially need the assistance of one another but are not likely to get that assistance from the benevolence of strangers (1981: 26). Smith also agrees that, when norms of respect for property, trade, and contract are well- entrenched, each person’s self-love and localized benevolence will lead him to serve the interests of others.
It is not from the benevolence of the butcher, the brewer, or the baker, that we expect our dinner, but from their regard to their own interest. We address ourselves, not to their humanity, but to their self-love, and never talk to them of our own necessities but of their advantages. (1981: 27)
One’s beneficial cooperation does not depend on ultimate concern for the ends of others. Indeed, individuals participate in vast networks of cooperation without having knowledge of the particular ends of other participants — or even knowledge of who the other cooperating parties are (1981: 22). We can coordinate with one another peacefully and to mutual advantage through «the obvious and simple system of natural liberty,» which leaves each individual «perfectly free to pursue his own interest in his own chosen way …as long as he does not violate the laws of justice» (1981: 687). These laws of justice channel or regularize our pursuit of our own ends and others’ pursuit of their own ends in such a way that we each best serve our interests by way of serving one another’s interests. The genius of the simple system of natural liberty is that it enables us to live together in mutually beneficial ways without our having to surrender our separate and distinctive goals. Each «intends only his own gain, and he is in this, as in many other cases, led by an invisible hand to promote an end which was no part of his intention» (1981: 456).