This post is an addendum to my series on marriage. You should probably read at least part one of that series before this post in order to understand what I’m talking about.

The most common objections to a procreative understanding of marriage result from the failure to appreciate that institutions are teleofunctional in nature, and so possess the distinctive character of teleological kinds. Teleological kinds display the following features:

A) Human intentions do not determine an object’s function. One may intend to use a toaster as a door jam, or a space heater, or to illuminate a room by the glow of its electric coils, but none of these things are its function (what Millikan calls a direct proper function). These uses are what Millikan would call “derived” proper functions; the sense in which we would say that the toaster is functioning as a heater is derived from the user’s intentions (Language, Thought, and Other Biological Categories, ch. 2). Prototypes of artifacts have only derived functions, when they begin to be replicated because they produce some effect they acquire a direct function as well.

B) An item may be able to perform its function only if external conditions are right, and yet because conditions are never right, the item may never perform its function. Millikan gives as an example an ice-cream machine. In order for an otherwise working ice-cream machine to perform its function, it needs to be hooked up to the appropriate environment and receive the appropriate ingredients as inputs. But because in this example the environment is never right and this particular ice-cream machine is never actually loaded with the correct ingredients, or plugged in and turned on, it never performs its function. And yet making ice cream remains its function (see “Existence Proof for a Viable Externalism,” The Externalist Challenge. New Studies on Cognition and Intentionality, p. 230).

C) An item with a teleofunction may be physically unable to perform it. A diseased heart may be unable to pump blood, yet that remains its function. It is because the possession of a teleofunction is a matter of what one’s ancestors did that the current item may lack these features and yet still have the performance of that action as its function.

D) The possession of a function is an objective fact. It is not a matter of opinion, or interpretation, or a matter of social agreement. It is a fact that the function of the heart is to pump blood. Anyone thinking otherwise is factually wrong. Aristotle thought that the function of the brain was to cool the blood; his proposition to that effect was false. Indeed, generations of biologists may be in agreement as to the function of some mechanism, and yet be wrong about it.

E) An item may fail in the performance of its function more often that it actually achieves it. For example, certain animal mating dances might fail more often than they succeed, yet they succeed often enough to make it worthwhile to keep them in use.

F) Saying that an item has a function is not to provide a conceptual analysis of the concept of that item. In describing an item’s function one is not giving a list of necessary and sufficient conditions for being that thing; having a function is neither necessary nor sufficient for producing the effect in question. Being a heart is a matter of possessing a certain history, and this history can not be revealed by conceptual analysis. In addition to possessing this history, in order to perform a function conditions must be what Millikan calls Normal conditions (LTOBC, p. 33). Even pumping blood can be missing from a heart, as is the case in deceased, diseased, or damaged hearts, and yet pumping blood remains the heart’s function.

With these features of teleological phenomena in mind we can see how the arguments for gay marriage make invalid assumptions. They almost always assume an essentialism where a single counterexample can invalidate a principle. Teleological phenomena, however, do not work this way. Take the following commonly heard arguments for gay marriage:

Objection 1: Preventing the problems that result from heterosexual intercourse can not be the function of marriage since people get married for all sorts of reasons other than the having and rearing of children. Couples might marry for wealth, to secure an alliance, to receive tax breaks, for companionship, to avoid deportation, and so on.

Feature (A) above answers this objection; functions have nothing to do with an individual or group’s intentions. For example, a screwdriver could be used to fulfill various intentions–as a weapon, a can opener, a hole puncher, etc.–but its (direct as opposed to derived) function is to turn screws. That is what it was reproduced for its ability to do. Furthermore, even if it is constantly used as a space heater, toasting remains the function of a toaster. Whatever its derived function may be, its direct function does not change. Likewise, those entering a police force might be doing it for financial gain, and not law-enforcement, but that remains the institution’s function.

Objection 2: Marriage can have nothing to do with the production of children since lots of people might get married and decide not to have children. Or they may be infertile and unable to have children. A procreative understanding of marriage would say that these couples are not married because they do not perform the function of marriage. To quote Adele Mercier, “Anyone who thinks that the essence of their union is to produce children are mistaken unless they are ready to consider their marriage as having never existed at all should it result in no children” (The Monist, 91 (2008), p. 4).

Feature (B) above explains why an item or institution may have a function and yet never perform it. Imagine a police department that is lucky enough to exist in a place where there is no crime and so no criminals ever need to be apprehended. The apprehension of criminals is still its function despite the fact that it is not performed. Or simply imagine an otherwise working toaster that is never actually used to toast items. Toasting is still its function even though it is never performed. Similarly, a marriage that never performs its function still has that function. Likewise, with infertile couples, feature (C) shows that even if an item is unable to perform its function, it still has that function as its function. A broken toaster or malformed heart still has their distinctive functions even if they are unable to perform them. An infertile heterosexual couple still forms a natural reproductive unit with the function to produce offspring even if it is unable to perform that function. All that is required for marriage is that the couple forms a natural reproductive unit and takes the vows.

Objection 3: It can not be the function of marriage to prevent the problems that result from the production of children because many married couples do not prevent these problems. Parents may be abusive or neglectful, or otherwise make bad parents. In fact, they may make the problems worse than they would have been if they did not raise the child.

Feature (E) answers this objection. An item may still have a function even if it sometimes, frequently, or almost always fails. Police departments have the function to prevent crime even though they often fail to do so, the camouflage of a snowshoe hare has the function to avoid detection by predators even though most hares get eaten anyway, and the vast majority of sperm fail to perform their function of fertilizing an egg. All that matters is that the item succeeds often enough to make it worth while to keep around.

Objection 4: An infertile couple may happily remain together for decades. How can you say that this is an unsuccessful marriage?

Mutual love and happiness are great Aristotelian virtues of marriage; they are properties that help to enable a marriage to perform its function. And so this marriage is good insofar as it displays these virtues. However, it has been a monumental error to mistake the virtue of marriage for its function: love is not the function of procreative marriage. Furthermore, no one would deny that a couple that lovingly raise a child display other virtues, and that these are by necessity missing in the case of a childless couple. People may join all sorts of institutions and get much satisfaction out of them without ever successfully performing the function of the institution.

Objection 5: The argument begs the question by describing the problem in such a way that it excludes homosexual couples. It has defined marriage as preventing the problems that result from heterosexual intercourse, namely, the production of a child. Considering that this definition of marriage contains “heterosexual” right in the definition, of course homosexuals will be excluded.

Feature (F) above answers this objection. A teleofunctional account of marriage is not a definition or conceptual analysis of the concept of marriage. Since the argument does not rely on an analysis of “marriage” it does not beg the question to point out that functionally successful heterosexual intercourse has certain consequences missing from homosexual intercourse, and that these consequences might need a social institution with which to address them. If Aristotle was allowed to define the brain as an organ whose function it is to cool the blood, then he could never be refuted by those arguing otherwise, he could only be shown that the item which he took to be a brain, that lump of grey matter in the skull, was not in fact a brain. Anyone arguing otherwise would be accused of begging the question by including their new account of its function in their definition.

Objection 6: “Marriage is neither necessary nor sufficient for recognizing the dignity of children, for procreation, or for encouraging the flourishing of another person (by bringing him or her into existence.” (Brook Sandler, Social Philosophy Today 26 (2010) p. 27.)

Feature (F) answers this objection as well. No social institution is necessary or sufficient for performance of its functions: police departments are neither necessary nor sufficient for stopping crime, schools are neither necessary nor sufficient for education, hospitals are neither necessary nor sufficient for healing the sick. Yet those activities remain the institutions’ functions. The same goes for other functional items such as biological organs, behaviors, or manufactured artifacts. Functions are a matter of what has happened sufficiently often in the past (even if rarely) that explains why an item has been reproduced, and that something has happened in the past is no guarantee (in the form of necessary and sufficient conditions) that it will happen in the present since conditions may not currently be those found in the past that enabled the item to produce the effect for which it has been selected. In Normal conditions an item will be caused to perform its function as a matter of natural law, not metaphysical or logical necessity.

Objection 7: What if a homosexual undergoes a sex change operation to become the opposite sex. Can they then marry their partner?

Sex change operations do not change an individual’s sex (and are usually instead called gender reassignment procedures). Sex is a functional category and is assigned by nature. Sex change operations may however make life more pleasant for one whose sex and sense of sexual identity do not correspond.

Objection 8: Even if it once was the function of marriage to prevent the problems that result from the production of children, its function can change over time and so come to possess a different function.

The function of marriage does not change. More specifically, for as long as the combination of egg and sperm produces children, and this creates problems that can be prevented by the parents taking on certain obligations, marriage will have the function of preventing these problems. This is different from saying that this institution will inevitably be called “marriage.” And it is different from denying that the obligations of an institution might change, even to the extent that it no longer addresses the original problem. And it is different from saying that an institution may start solving a new problem, and no longer address the old one, and carry the institutional name along with it as it now solves this new problem. However, once a “new” institution is started to address the original problems, this institution will be marriage (again, even if it does not carry the name and some other institution does).