While often hostile to the Calvinist Christianity in which he was reared, David Hume’s essay “Of Polygamy and Divorces” offers a vigorous and well-argued defense of marriage arrangements as they existed in England and many other parts of Europe from the early Middle Ages through most of the 18th century. His arguments have great relevance for us today as we struggle to cope with unprecedented rates of divorce and unprecedented ease of both entering into and exiting marriages and other intimate procreative relationships. His arguments against polygamy are also important as that practice seems to be undergoing something of a resurgence in parts of the southwest, with renewed interest in the popular culture.

Hume begins the substantive part of his inquiry with a brief description of the great variety of marriage practices and customs that have existed throughout the world, noting that “as circumstances vary and the laws propose different advantages, we find that, in different times and places, they impose different conditions” on the marriage contract. Custom and law in different times and places have permitted polygamous marriages (one man with several wives); confined one man to one woman (sometimes allowing for divorce and remarriage and other times not); permitted one man to have two wives but no more than two; assigned multiple men to one wife; permitted group marriages between numerous men and numerous women; and even, as in the case of Tonkin (Vietnam), permitted foreign sailors “when the ships come into harbor” to engage in temporary marriages with local women that lasted only for a season.

But Hume is no cultural relativist and rejects the view that all marriage customs are equally good at producing desirable results. Much of his essay is devoted to showing the many harms and disadvantages of two of the most common types of marriage arrangements outside the Christian West: polygamy in which men have multiple wives, and monogamous marriages in which the spouses are permitted to dissolve their marriage and marry someone else.

Hume begins his critique of polygamy with the challenge of a hypothetical defender. Having multiple wives, says the polygamy defender, is “the only effectual remedy for the disorder of love and the only expedient for freeing men from that slavery to the females which the natural violence of our passion has imposed upon us.” It is by multiple partners alone—partners who can be used at will and played off one against the other—that “[we men] regain our right of sovereignty, and sating our appetite, reestablish the authority of reason in our minds, and, of consequence, our own authority in our families.”

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Hume’s answer to the polygamy defender continues in the tradition of Locke’s famous attack on patriarchy and does so in a manner that strongly resonates with contemporary liberal sensibilities. The sovereignty of the male in a polygamous marriage, says Hume, “is a real usurpation and destroys that nearness of rank, not to say equality, which nature has established between the sexes. We are, by nature, their lovers, their friends, their patrons: Would we willingly exchange such endearing appellations for the barbarous title of master and tyrant?”

The calamities brought on by polygamous marriage do not stop with the adults in the arrangement, according to Hume. Children brought up under such a marriage learn only the lifestyle of masters and slaves and never come to understand the importance of human equality. The huge number of offspring produced by such an arrangement also deprives each child of substantial fatherly guidance, since a polygamous father will have little time to spend with each of his numerous progeny. “Those who pass the early part of life among slaves,” says Hume, “are only qualified to be themselves slaves and tyrants, and in every future intercourse either with their inferiors or superiors are apt to forget the natural equality of mankind. What attention, too, can it be supposed a parent, whose seraglio affords him fifty sons, will give to instilling principles of morality or science into a progeny with whom he himself is scarcely acquainted…?”

Having dispensed with polygamous marriage, and “matched one man with one woman” as a more desirable marital arrangement, Hume turns his sights to the “duration we shall assign to their [monogamous] union” and to “whether we shall admit of those voluntary divorces which were customary among the Greeks and Romans.” The arguments of the defenders of divorce seem strong: “Let us separate hearts which were not made to associate together,” they say, so that divorcing spouses “[may each] find another for which it is better fitted.” “Nothing can be more cruel,” they continue, “than to preserve by violence an union which, at first, was made by mutual love, and is now, in effect, dissolved by mutual hatred.”

Hume responds to these arguments on two fronts: the welfare of children and the happiness of spouses. His arguments closely parallel those of the critics of our contemporary “no fault” divorce culture. “What must become of the children upon the separation of the parents?” he asks. “Must they be committed to the care of a stepmother, and instead of the fond attention and concern of a parent, feel all the indifference or hatred of a stranger or an enemy? … And shall we seek to multiply those inconveniencies by multiplying divorces and putting it in the power of parents, upon every caprice, to render their posterity miserable?”

Hume clearly believed, as did almost all the English of his day (and almost all Americans until quite recently), that children generally thrive best when brought up in a two-parent, husband-wife household, where the children are the biological offspring of both parents. Both reason and common experience justified such a judgment. Divorce and the breakup of the marital household were viewed as harmful to children, since, even if the divorced parents remarry, step-parents usually don’t have the same warmth or commitment in rearing other people’s children as in rearing their own. This for Hume—and most of his contemporaries—was a simple fact of everyday experience that needed no proof. Stereotypes of wicked or cold stepmothers existed precisely because the stereotypes contained a good deal of easily observable statistical truth.

What Hume has to say about divorce and the happiness of spouses contains his most profound insight into human relationships and the difficulties of sustaining marital happiness. Contrary to what some romantics may think, marital happiness and conjugal human love cannot be sustained by amorous or infatuating passions, Hume says, since they are by nature unstable and fleeting. “Amorous love,” he says, “is a restless and impatient passion, full of caprices and variations—arising in a moment from a feature, from an air, from nothing, and suddenly extinguishing after the same manner.” Whatever its value may be, no marriage can be sustained by it.

Hume proposed as his alternative the companionate friendship that is fostered by and preserves marriage. This, Hume says, is an affection “calm and sedate … conducted by reason and cemented by habit, springing from long acquaintance and mutual obligations, without jealousies or fears, and without those feverish fits of heat and cold, which cause such an agreeable torment in the amorous passion.” Abiding friendship and the sharing of life’s experiences and tasks, says Hume, are what render the married state both endurable and happy.

Does the presence of an option for “voluntary divorce” within a marriage negatively affect the cultivation of friendship between the marital partners and hence their conjugal happiness? It does, says Hume, and it does so in a powerful way. If spouses know they can divorce at will and seek their marital bliss with another partner, the relationship dynamics within marriage, he believed, would be radically altered and in such a manner that diminishes marital stability and marital happiness. With no sense of obligation to stick together through thick and thin, they would be less inclined to work together to iron out their differences and keep their conjugal friendship alive.

There is a paradox here, Hume acknowledges, in that “the heart of man naturally delights in liberty,” and the liberty to marry the person of one’s affection is acknowledged as an important ingredient in marital happiness. But once married, the liberty of easy divorce has the opposite effect on a couple’s happiness, Hume says, and he gives as an historical example the decline in marital happiness that followed Rome’s abandonment of its ancient proscription of divorce. Under the older dispensation, says Hume (citing the Roman historian and orator Dionysius Halicarnassus), marriages were generally harmonious and satisfying, as couples “considered the inevitable necessity by which they were linked together and abandoned all prospect of any other choice or establishment.” “The heart of man naturally submits to necessity,” Hume explains, and it will soon lose “an inclination when there appears an absolute impossibility of gratifying it.” The secret to happy marriages thus involves principles of both freedom and constraint, principles Hume readily acknowledges that seem to contradict one another. “But what is man,” he muses, “but a heap of contradictions!”

Hume would no doubt agree with the claim of Dietrich Bonhoeffer in his prison “Wedding Sermon”: “It is not your love that sustains the marriage, but from now on, the marriage that sustains your love.” The no-divorce-option marriage, for Hume, is an institution that binds spouses together through strong social and legal obligations, and gives them permanent incentives to sustain and deepen their mutual friendship and love.

Looked at from our current perspective with more than three decades of experience behind us of divorce-on-demand laws—and a cultural value system paralleling them—Hume’s critique seems uncannily prescient. Sociologists specializing in family issues, including Sara McLanahan, Paul Amato, and David Popenoe, have documented the substantially greater risk to the children of divorce with regard to virtually every “social bad” that social scientists can measure—e.g., drug and alcohol addiction, teen pregnancy, child abuse, depression and mental illness, poor school performance, juvenile delinquency, and increased risk of injury from accidents. This greater risk holds true whether the children of divorced parents wind up in single-parent, step-parent, mother-and-grandmother, mother-and-boyfriend, or father-and-girlfriend households. Growing up with two biological parents, in an intact, husband-wife family, with the parents committed to lifelong monogamy and working together as a team, has been shown to benefit children in countless ways.

And just as Hume would have predicted, recent research suggests that our easy divorce laws may have contributed to the well-documented decline in overall marital happiness over the past four decades, a decline seen even among couples who do not divorce. Summing up the results of recent studies, Linda Waite and Maggie Gallagher note that “even as divorce [in the 1980s] became an easier, more common, and more acceptable outlet for marital unhappiness, marriages became unhappier.” In surveys since the 1970s, couples increasingly rate their marriages as unsatisfactory, even those who remain married and do not follow the divorce route of so many other Americans.

Waite and Gallagher conclude with a quotation from two other marriage researchers that could stand as a fitting epigraph to Hume’s much-neglected and prescient essay: “Ironically, by adopting attitudes that provide greater freedom to leave unsatisfying marriages, people may be increasing the likelihood that their marriage will become unsatisfying.” And one could add: “unsatisfying and unhappy to all concerned—the spouses, their children, their relatives, their friends, their fellow church members, and the surrounding social order more generally.” With his keen insight into people—and his uncommon degree of common sense—David Hume would have understood America’s current marriage crisis only too well.