A Treatise of Human Nature

Hume turns to what he describes as “artificial virtues,” which are virtues that come out of social and cultural norms. Specifically, Hume contemplates why he would pay back a loan a person gave him, asking if he would pay him back just because he was “train’d up according to a certain discipline and education” (351) or if he would pay him back in a world where ideas of justice are cruder. These questions lead Hume to assert that an action is only seen as a virtue if it shows that a person has a virtuous motive. For Hume, there is no virtuous motive for justice located within human nature. Our concern for the public good and our desire for a good reputation does not cover all cases of justice; our concern for our loved ones does not explain why justice is a universal value and our self-interest often works against justice. Hume concludes instead that the idea that justice is a social invention is “obvious and absolutely necessary” (536).

Using justice as a social construct as a starting point, Hume investigates why justice is invented. Justice comes out of mutual self-interest in order to have a functioning society that can manage and protect our rights, our property, and obligations to each other (542). Hume labels this mutual self-interest as “public interest” (548). Further, justice is necessary to keep excessive self-interest from doing too much damage and to deal with the fact that the resources people need have to be carefully managed. While justice is necessary for society, our ideas of justice and injustice still have moral force that goes beyond just being good for social harmony. Hume argues this is for three reasons. First, we have sympathy with the public interest, which means that we sympathize with the injustice suffered by another person. Second, our politicians and parents define the rules of justice and impress those rules upon us. Third, our anxiety over our public reputation makes us sensitive to how our actions going for or against justice can make us look to the people around us (551-52).

Hume views three laws based on justice that are “absolutely necessary to human society” (553): possession must be stable (e.g., rules and norms that make sure no one person or group can hoard all resources), transference by consent (e.g., the right to bestow one’s belongings to another person of their choosing, such as through inheritance), and performance of promises (i.e., that there is some guarantee that people will follow through on their agreements, such as through legal contracts). These laws were established through our imagination, specifically the concept of ownership emerging from the association of ideas between property and its owner. Like justice, they come out of public interest, fear for one’s reputation, and social custom. These laws are also artificial like justice.

Hume lists three more reasons why justice is artificial. First, justice is concerned with property to the point that much of justice is about property. Since property is clearly a social construct, it would follow that justice is as well. Second, our natural moral ideas are nuanced because they are based on our individual experiences, while our ideas of injustice and justice are much more rigid. Third, we think of justice and injustice as general concepts, while natural moral ideas are more able to consider different factors and circumstances in the present time (580-84).

Next, Hume considers government and its origins. Government is necessary because people are overly motivated by their self-interest or their interest just for their friends and loved ones. People are so short-sighted that they “often act in contradiction to their own interest” (586). Hume theorizes that, historically, governments started when human groups first went to war with each other. The leaders of these first battles are also soon given authority in times of peace, once the advantages of a government become clear (591-92). Still, Hume rejects social contract theory, the idea that government is based on the consent of the governed. Instead, he believes it is based on the public interest of everyday people for an institution that will regulate the social agreements that keep society in order. Governments themselves develop a motive in protecting the interests of their people. In place of a contract between the government and the governed, Hume sees the matter of government as the public and the government having parallel interests.

However, when a government becomes tyrannical and threatens the public interest of the people, the people have a right to resist. Even so, Hume suggests that the best governments for the public interest are those where allegiance is clear. Hume lists five sources of government authority: long possession (a government that has existed for a long historical period), present possession (a government that currently holds authority and legitimacy), the right of conquest (even a government established by conquest is made more legitimate by ideas of glory than one formed by a usurper), succession (government through hereditary rule, such as monarchy), and positive laws (when an assembly of the people set up laws and those who will rule) (607-12).

As for relationships between governments, Hume argues that governments follow the same three laws based on justice. However, “there is a system of morals calculated for princes, much more free than that which ought to govern private persons” (618). This is because governments do not have as strong a need for mutual interest between each other as individual people do.

In conclusion, Hume looks at laws and norms dealing with chastity and modesty. Again, like justice, chastity and modesty are artificial virtues constructed by society. However, Hume argues they are needed to deal with natural issues of family life and childrearing. Specifically, because women are the ones who have children and the paternity of a child cannot be easily or even certainly proven (at the time of Hume’s writing), laws and custom have to more strictly regulate the sexual behavior of women than that of men (623-24).