It is true, however, that classical liberals--or libertarians--have not given much explicit attention to family life. And yet, a few--such as Steven Horwitz--have begun to elaborate a classical liberal theory of the functions of the family as shaped by human evolutionary history. In doing that, they show how a Darwinian liberalism can support a conception of the family as an expression of evolutionary natural law.
Horwitz has sketched a Hayekian theory of the family in response to the claim of Geoffrey Hodgson that Hayekian liberalism must deny the importance of the family. Hodgson has written:
"Generally, if contract and trade are always the best way of organising matters, then many functions that are traditionally organised in a different manner should become commercialized . . . Pushed to the limit, market individualism implies the commercialization of sex and the abolition of the family. A consistent market individualist cannot be a devotee of 'family values' . . . They cannot in one breath argue that the market is the best way of ordering all socio-economic activities, and then deny it in another. If they cherish family values, then they have to recognise the practical and moral limits of the market imperatives and pecuniary exchange" (1999, p. 84).
Against this, Horwitz denies Hodgson's claim that Hayekians must assume that "the market is the best way of ordering all socio-economic activities." On the contrary, Horwitz shows, Hayek is clear that markets and other processes of spontaneous ordering are only effective for certain kinds of social activities. Hayek distinguishes "spontaneous orders" as "grown orders" from "organizations" as "made orders," and he makes it clear that any large society requires both kinds of ordering. "In any group of men of more than the smallest size," Hayek explains, collaboration will always rest both on spontaneous order as well as on deliberate organization," because "the family, the farm, the plant, the firm, the corporation and the various associations, and all the public institutions including government, are organizations which in turn are integrated into a more comprehensive spontaneous order" (1973, p. 46).
Spontaneous ordering works best for social coordination where the tasks are very complex and where they involve large numbers of people who interact anonymously. But deliberate organization works best for those tasks of social coordination that are simple enough and involve such a small number of people interacting face-to-face and sharing a common purpose that they can be planned out by deliberate design. The family is one of the social institutions that works best as a deliberate organization rather than as a spontaneous order.
It is important, then, Hayek explains, that we neither apply the rules of the market to family life nor apply the rules of family life to the market. "If we were to apply the unmodified, uncurbed, rules of the micro-cosmos (i.e., of the small band or troop, or of, say, our families) to the macro-cosmos (our wider civilization), as our instincts and sentimental yearnings often make us wish to do, we woud destroy it. Yet if we were always to apply the rules of the extended order to our more intimate groupings, we would crush them. So we must learn to live in two sorts of world at once" (1988, p. 18).
Family life serves at least three functions in satisfying our evolved natural desires for sexual mating, parental care, and familial bonding. Parental care provides for human offspring who have evolved needs for adult care to secure their existence, their nourishment, and their social education, which make possible their growth into healthy adults. Childless families satisfy the evolved human desires for spousal love and kinship ties.
As Horwitz indicates, Hayek's idea of "living in two worlds at once" points to the need for the family as an institution in which children can learn the moral rules for both the micro world of face-to-face interactions and the macro world of anonymous interactions in the extended spontaneous order of society.
The Hayekian insight is that families are best situated to do this because of their advantage in knowledge and incentives. The intimacy of the family allows parents to have an intimate knowledge of each child's individual character and situation that allow parents to teach them their social lessons--by both explicit instruction and implicit example--in a manner that is suitable for the individual child. At the same time, parents (normally) have a love for their children that gives them the incentives to care for their children's rearing in a way that is specially designed for them. No extended order of spontaneous cooperation could provide either the knowledge or the incentives that arise within the intimate experience of families.
The reasons that justify private families--because parents have the most knowledge of their children and the strongest incentives to care properly for their children--are comparable to the reasons that justify private property, because private property owners have the knowledge and the incentives to care best for that property.
We might also notice that this special role of the family in transmitting social learning about how best to succeed in society could explain the great transformation that came with the Industrial Revolution. If we accept Gregory Clark's argument about the importance of an evolutionary process of "survival of the richest" by which families that taught their children the bourgeois virtues were more successful in England in the 18th century, which led to the Industrial Revolution, then we could explain this great transition into Hayek's Great Society as a product of an evolutionary transformation in family life.
Hayek, F. A., Law, Legislation, and Liberty, Vol. 1 (Chicago: University of Chicago Press, 1973).
Hayek, The Fatal Conceit: The Errors of Socialism (Chicago: University of Chicago Press, 1988).
Horwitz, Steven, "The Functions of the Family in the Great Society," Cambridge Journal of Economics, 29 (2005): 669-684.
Some related posts and articles can be found here here, here, here, and here.