‘Marriage … is a lifelong union between one man and one woman …’ (Professor Norman Doe, Christian Law (2013), p.394)
Though formulated less than a decade ago, this alleged ‘principle of Christian law common to Christian Churches’ has not aged well. It was, of course, published in the same year that Parliament approved the Marriage (Same Sex Couples) Act.
Now the Professor’s own ‘ecclesial community’, as he describes it (p.viii), the Anglican Church in Wales, is considering a proposal to authorise a liturgical rite of blessing of same-sex marriage. (Blessing only, because the solemnisation of same-sex marriage in church is at present forbidden by the secular law.)
The proposal is accompanied by an ‘Explanatory Memorandum’ signed by all 6 of the Welsh bishops. This argues that blessing a same-sex marriage is justified by the Bible, as interpreted with the aid of ‘new social, scientific and pyschological understandings of sexuality’.
Despite a widespread and 2,000-year-old perception to the contrary, the Bible does not condemn homosexual acts per se. It condemns only lust (or porneia in Greek), albeit it tends to identify lust with homosexual acts rather than heterosexual ones. The moral quality of a homosexual act therefore depends, not on the act itself, but on the intention or motive of the actors. An act that is motivated by lust is bad. However, one that is motivated by love is good.
Persons who enter a same-sex marriage demonstrate thereby that they are motivated by love, not lust. The Church should therefore bless such marriage.
In pre-modern times legal discussion of marriage concentrated on the conditions necessary for a valid marriage (consent, absence of impediments, dispensation from impediments, ceremonial formalities) and the consequences of invalidity (the legitimacy of children, title to property). Recent incidents of forced marriage, and of marriage ceremonies not recognised by law, have led to a revival of interest in these matters. In modern times, discussion turned to the circumstances (if any) in which a marriage can be dissolved, and the consequences of marriage breakdown (financial support, custody of children).
However, the recent phenomenon of same-sex marriage raises the most fundamental issue of all. What is marriage? Assuming that all conditions for its validity are satisfied, how does a marriage come into being?
The Church in Wales Memorandum does not begin to address this question. Even if it was possible to accept its biblical exegesis on homosexual acts, this does not explain how a same-sex relationship, with or without sexual acts, is capable of constituting a marriage. Allusions to marriage are expressed in fluffy abstractions: ‘faithful and mutual commitment’, ‘loving and faithful commitment’, ‘lifelong fidelity and mutual comfort’.
Recent political controversies on both sides of the Atlantic have prompted much discussion of the constitutions of the United States and the United Kingdom. The American and British constitutions are different in many ways, but they have one thing in common: they are both man-made.
Like the United States and the United Kingdom, marriage also has a constitution. Unlike them, however, this constitution is God-given, not man-made. The Book of Common Prayer teaches that marriage was ‘instituted of God [i.e constituted by God] in the time of man’s innocency’. In the case of Dalrymple v Dalrymple (1811) 161 English Reports 665, Sir William Scott, Lord Stowell, observed that marriage ‘is the parent, not the child, of civil society’ (p.669). This God-given constitution of marriage is the foundation of all other constitutions of human society.
Marriage has 2 essential constitutive elements, which are conveniently summed up in 2 Latin words (1) consensus and (2) copula.
The Prayer Book describes marriage as a covenant. Lord Stowell described it as ‘a contract according to the law of nature … wherever 2 persons of different sexes engage by mutual contracts to live together (Lindo v Belisario (1795) 161 English Reports 530, p.636). The different terminology reflects the dual heritage of Christianity, Jewish-Biblical (covenant) and Graeco-Roman (contract, natural law).
Secular law agrees with ecclesiastical law. ‘The contract [of marriage] itself, in its essence … is a consent on the part of a man and a woman to cohabit with each other, and with each other only’ (Harrod v Harrod (1854) 69 English Reports 344, p.349)
Consensus or contract / covenant is, of course, not remotely unique to marriage. A vast multitude of human relationships – economic, political, international and ecclesiastical (including the Church in Wales itself, of course) – are constituted by contracts of one sort or another.
The unique constitutive element of marriage is therefore the union, or copula, that proceeds from the consensus.
Consensus is inseparable from copula. Lacey and Mortimer confirm that ‘the institution [of marriage] consists in  a contract [consensus] and  its fulfilment [copula]’ (Marriage in Church and State (1912-47), p.39). They explain the relationship between the two
‘the surrender of the body is common alike to marriage and to illicit intercourse … the intention which makes it marriage cannot be adequately expressed without words or their equivalent’.
Thus sexual intercourse per se does not constitute copula. Copula requires prior consensus. Pre-marital intercourse between the couple is not consummation.
Lord Stowell observed that ‘A marriage is not every casual commerce [i.e sexual relationship]; nor would it be so even in the law of nature … But when 2 persons agree to have that commerce for the procreation and bringing up of children, and for such lasting cohabitation … That, in a state of nature, would be a marriage and … in the sight of God’ (Lindo v Belisario again, p.636).
Union, or copula, has both a metaphysical and a physical dimension.
The Prayer Book tends to emphasise the metaphysical dimension of union. The couple are ‘joined together by God’. Marriage signifies ‘the mystical union that is betwixt Christ and His Church’. However, the Prayer Book does refer to the physical dimension of union as ‘one flesh’.
The concept of marriage as one flesh is, of course, of biblical origin, and is affirmed by Christ Himself
‘the Creator made them from the beginning male and female … For this reason a man shall leave his father and mother, and be made one with his wife; and the two shall become one flesh … they are no longer two individuals; they are one flesh’ (Matthew 19, vv4-6).
This makes clear that marriage engages, not merely the constitution of all human society, but the very constitution of the human person, created male and female.
A married couple are joined together by a metaphysical act. Marriage is made in Heaven. But even Divine Grace yet requires human cooperation. The newlyweds cannot simply rely on God to effect their union. They are called to do their bit as well! The physical dimension of copula is effected by marital intercourse. Intercourse between the couple completes, or consummates, their marriage. The biblical phrase ‘one flesh’ could hardly make this clearer.
The precise relationship between consensus and copula was much discussed in the mediaeval Church. Robert E Rodes noted that ‘mediaeval canon law vacillated between  consent and  marital intercourse as the effective consummation of the marriage’ (‘Canon Law as a Legal System’, Natural Law Forum (1964) p.47n)
Messrs Coriden, Green and Heintschel relate that
‘the Paris school [theologians] taught that consent alone was necessary for a true marriage, while the Bologna school [canonists] held that consent was the beginning of marriage, but only with sexual consummation did a true marriage come into existence’ (The Code of Canon Law. A Text and Commentary (1985), p.812)
The papacy, characteristically, struck a compromise between these 2 schools of thought
‘true marriage exists from the moment of consent; when this consent is completed with sexual intercourse, the property of absolute indissolubility is added … the two becoming one flesh’.
Law has much more to say about consensus than about copula. If a marriage contract is validly made then consummation is presumed. However, proven non-consummation is a ground of nullity in law.
It is interesting to compare the English and Roman Catholic laws on this matter. Non-consummation is not an automatic ground of nullity under either law. In England and Wales, an unconsummated marriage is said to be voidable rather than void. There is a prima facie right to a decree of nullity, but this may be lost on equitable grounds (Matrimonial Causes Act 1973, ss.12 and 13).
In Roman Catholic law an unconsummated marriage may be dissolved, rather than annulled, for a ‘just cause’ (1983 Code, canon 1142). This power forms a rare exception to the Catholic teaching that a valid marriage contract is indissoluble. In England and Wales a non-consummation case can be decided by the local county court. In the Catholic Church such cases are reserved to the Pope himself. No lesser authority may decide them.
English law therefore implies a spouse’s right to consummation of the marriage. Roman Catholic law implies the couple’s joint duty to consummate. However, both laws make clear that an unconsummated marriage is constitutionally incomplete.
Constitution and Purpose
The Prayer Book identifies 3 purposes of marriage, ‘the causes for which matrimony was ordained’:
(1) children. Thus children are not constitutive of marriage. Copula does not require conception. The Prayer Book explicitly acknowledges this by providing that a prayer for the procreation of children ‘shall be omitted where the woman is past child-bearing’.
(2) sexual love. Influenced, no doubt, by celibate mediaeval theologians, the Prayer Book is somewhat grudging in its treatment of this purpose, describing it as ‘a remedy against sin, and to avoid fornication, [for] such persons as have not the gift of continency …’. (This also explains the paucity of reference to marriage as ‘one flesh’.)
Lacey and Mortimer astutely point out that marriage qua ‘remedy against sin … seems to conflict with the statement that it was instituted in the time of man’s innocency’ (op cit, p.28).
Modern liturgies are more generous. Common Worship states that ‘Marriage brings husband and wife together in the delight and tenderness of sexual union’. Its predecessor, the Alternative Service Book (1980), stated that marriage is given so that the couple ‘may know each other in love, and, through the joy of their bodily union, may strengthen the union of their hearts and lives’.
(3) Archbishop Cranmer, the first married Archbishop of Canterbury, sought to balance the negative mediaeval view of sex by the providing that marriage is also ‘for the mutual society, help, and comfort, that the one ought to have of the other, both in prosperity and adversity’ (D MacCulloch, Thomas Cranmer (1996), pp.420-1)
Purposes (2) and (3) are essentially the same – love. They merely refer to different aspects of married love, erotic or sexual love, and friendly, companionable love. Thus marriage has 2 essential purposes, love and children.
It is important not to confuse the constitution of marriage (what is marriage?) with the purpose of marriage (what is it for?). Pleasant-sounding abstract references to marriage (such as those in the Church in Wales Memorandum) tend to do this.
Faith assures that God constituted marriage out of love for humanity, and love is, of course, a good motive for marriage. But love, like children, is not constitutive of marriage. Sad though it is, a marriage can still exist without love, just as it can exist without children.
Mere tender feelings cannot be constitutive of marriage. And the suggestion that love is constitutive of marriage carries the false implication that the only valid marriage is a happy one.
The Marriage Quadrilateral
The phenomenon of same-sex marriage raises 2 questions, which this analysis has sought to answer
(1) What is marriage? Marriage is consensus-copula.
(2) What is marriage for? Love and children.
Consensus, copula, love, children. Having identified this marriage quadrilateral, let us apply it to a same-sex relationship.
A same-sex relationship is not incompatible with consensus. It is, of course, perfectly possible for 2 persons of the same sex to make a contract, or ‘covenant’, to live together unto their lives’ end.
A same-sex relationship is biologically incapable of producing children. However, as discussed, children are not constitutive of marriage. A childless marriage is prima facie just as validly constituted as any other.
A same-sex relationship is capable of love. But again, love, like children, is not constitutive of marriage.
However, a same sex relationship is incompatible with copula. Even the current secular law does not deny the obvious biological fact, which it has no power to change. As amended by the 2013 Act, it acknowledges that its non-consummation provisions (discussed above) ‘do not apply to the marriage of a same-sex couple’ (1973 Act, s.12(2)).
It may be thought that the mediaeval uncertainty about consensus-copula affords some sort of precedent for same-sex marriage. However, that debate concerned only the indissolubility of marriage, a different issue. It involved no denial that sexual consummation is a duty of marriage, or that procreation is a purpose of marriage.
Modern permissiveness is essentially the divorce of consensus-copula, albeit for contradictory reasons. Cohabitation outside marriage (what used to be called ‘living in sin’) implies that prior consensus is not necessary to copula, and may even hinder or restrict copula in some way. Same-sex marriage, by contrast, implies that consensus alone constitutes marriage, without the need for copula. Thus the permissive society both rejects the marriage contract and insists upon it.
Same-sex marriage is also the divorce of the 2 purposes of marriage, love and children. Children are not constitutive of marriage. And marriage is not, of course, a guarantee of children. As the Prayer Book makes clear, children are a blessing, not a right, of marriage. But the constitution of marriage serves the purpose of procreation. A same-sex relationship, by contrast, is constitutionally incapable of serving this purpose. A same-sex relationship is therefore not comparable to a childless marriage.
The link between married love and children first became controversial in the mid-20th century. The famous papal encyclical Humanae Vitae (1968) affirmed ‘the inseparable connection, established by God, which man on his own initiative may not break, between
 the unitive significance [love] and
 the procreative significance [children]
which are both inherent to the marriage act’ (para 12).
The Lambeth Conference 1930 loosened this connection somewhat by suggesting that ‘where there is … a clearly felt moral obligation to limit or avoid parenthood and where there is a morally sound reason for avoiding complete abstinence … other methods [than complete abstinence] may be used …’ (resolution 15).
However, despite the 20th century confusion over the precise nature of the link between married love and children, there was no denial that the link exists.
It is controversial to equate same-sex love with married love. It may seem self-evident that married love is unique to marriage, i.e consensus-copula. The Catholic Church apparently denies that same-sex love is of the same quality as married love. Homosexualitatis Problema (1986) (not an encyclical, but a letter issued with papal approval) stated that ‘the [homosexual] inclination itself must be seen as obiective inordinata‘ (para 3). The harsh-sounding Latin phrase could perhaps be rendered ‘confused’ in vernacular English. But law and love (and Latin) are different subjects, of course.
The authorities and commentaries discussed above support Professor Doe’s ‘common principle’. A same sex relationship is capable of 1 of the constitutive elements of marriage, and arguably resembles 1 of its purposes. However, it is not capable of the other 2 elements of the marriage quadrilateral. It is therefore not on all fours with the constitution of marriage to which the common principle bears witness.