First, St Paul applied the organic model not only to a cosmic context, but also to the co-operation of different talents in the day-to-day practical life of the Church.

Second, as the body of Christ, the Church continues the incarnation. To say that its divine and human aspects are readily separable is to risk perpetrating the Nestorian heresy - that there are separate divine and human persons in Christ. In this heresy, the divine subject does not in any sense experience human passions and suffering, and the human subject does not experience eternal unity with God the Father.

In the orthodox view, however, human nature in all its aspects is joined to the eternal divine person of the Son. Similarly, the most humble everyday aspects of church life are inextricably linked to the most elevated, mystical aspects.

Third, for this reason, the New Testament clearly affirms that it is the Church as a whole to which God has guaranteed the guidance of the Holy Spirit. So, the mind of the Church, over the long term and in all its widely dispersed places, is a crucial guide to the truth.

THE PROFESSOR takes the view she does partly because of her scholarly interests. Her greatest admiration is for the theologians of the late Middle Ages, when a tendency arose to view the institutional aspect of the Church in the same terms as secular politics. This view, moreover, tended to be pessimistic, and abandoned notions of a common good for arguments about formal entitlement to power.

This could favour either royal (and sometimes papal) absolutism or the idea that power derives from a contract made between initially isolated individuals. Either the one was favoured or the many, but, in both cases, mediation by the few was played down.

Combining both positions, Professor McCord Adams's hero, William of Ockham, held that an emperor must be instated democratically by the people, but afterwards alienation ensues. The supreme ruler exercises an absolute sovereignty over the populace; and this is delegated to him directly by God.

The few, who no longer have a part to play under this theory, had comprised not just wise or saintly individuals, but also voluntary associations intermediate between the state and the individual: examples of these are monasteries, orders of friars, universities, lay confraternities, urban or manorial communes, and economic guilds.

Each of these intermediate groups had exercised a political influence that was linked with their espousing objective values that were valuable not just because a king had decreed them or a majority of people had voted for them. It is no accident that both Tudor despotism and agrarian capitalism were boosted enormously by the dissolution of the monastic orders.

THIS favouring of either the one monarch or the many individuals (or both) at the expense of the few is often the political expression of two positions: the philosophical position known as nominalism, and the theological position known as voluntarism.

Nominalism, as opposed to realism (in its philosophical sense), is the view that only individual things exist. For example, there are many particular trees, but there is no universal form of treeness which the beauty of individual trees strives to manifest in many specific and different ways.

Likewise, individual things exist outside their relations to other things, so that the various relations into which things might accidentally enter leave their basic identities unaffected. In social and political terms, this implies, as Margaret Thatcher declared, that there is "no such thing as society", and no shared common good for which we can all work.

Instead, individuals have full identity outside all relations and before any political bond. Social and political institutions are just artificial constructs, which try to serve individual material happiness and safeguard individual choices. This is the intellectual background to modern individualism.

To apply such a view to the Church is, however, to lose sight of the fact that the Church is a performed sign of the unity of the Trinity. The Church aims at establishing and re-establishing a variegated harmony that expresses a shared truth beyond mere tolerance of others' whims.

VOLUNTARISM is approximately the view that the good is the good merely because this is what God has happened to choose. This means that we can know how to behave in any detail only by attending to divine revelation.

For Professor McCord Adams, such a position lines up with her nominalist individualism. General natures - of gender, for example - are fictions. All that is natural are the various supposedly given quirks of individuals, which are the result of God's arbitrary and playful preferences. It's like the way we might one day go for raspberry and another for chocolate ice-cream, though we like both equally, and the choice is really tricky - as the Professor once wrote in an article.

This is surely a very bad way of defending gay orientation and practice. If the important thing is simply to accept our supposedly given individual nature, and to act accordingly, then all and every physical or psychological deformity is sacralised as the will of God. Likewise, a licence is granted to people to interpret their most warped tendencies as an expression of divine preference.

A better argument would begin from a positive account of gay nature in general - the way in which it can be good, and can contribute to the common good.

NEITHER nominalism nor voluntarism, which gave rise to liberalism, is typical of Anglicanism. From Richard Hooker onwards, Anglican reform, on the whole, has been marked by a considered return to the metaphysical realism of the Church Fathers and most of the Middle Ages.

Realism accepts that universal essences, generally prevailing conditions, and constitutive relations are just as much real things as are individual existences. This has gone along with intellectualism: God is identical with a knowledge of the good, whose character he does not just arbitrarily decide.

Approaches to the Church and to politics, from Coleridge down to Rowan Williams, have reflected both outlooks. An organicist outlook, which sees society as in some sense a body, has, for this tradition, implied a whole that is more than its parts only because it is formed by the interaction of relatively independent parts - in the combining of our various gifts, for example.

The authoritarianism that Professor McCord Adams dislikes derives not from this intellectual tradition, but from her own. This has taken two forms. On the one hand, it has led to the imposition of an arbitrary artificial cultural structure on supposedly natural individuals, and to a perceived need for order above everything else.

On the other, it has led to the unleashing of individualist forces, and to a desire to find a civic guarantee for "natural" freedom. This has made state authorities so neurotically concerned about any interference by one person with another that they have established over-obsessive surveillance of citizens' behaviour. This paradoxically inhibits their freedoms altogether.

In either case, a bad model of organicism is also encouraged.

Only in the modern political tradition was the mystical body of the Church perverted into the idea of a secular nationalist unity that subsumes all beneath it and to which all else must be sacrificed.

Nevertheless, because the Church is founded on the truth, not on a majority vote, it is a "mixed constitution", which blends the monarchy of Christ with the democracy of the many, led by the Holy Spirit, and the aristocracy of the few, who are priests, religious, and learned or saintly laity.

So the Church should not copy secular liberal politics. Indeed, the latter should try to approximate to the mixed constitution of the Church, since, without education and mediation by the few, the many will succumb to propaganda, and the one will impose its arbitrary will.

Surely the ideological shape of naked individualistic liberalism is now plain for all to see, when the "defence of freedom" itself demands the Ockhamist alienation of natural individual rights to the power of state decision - as has happened at Guantanamo Bay.

The CHURCH's organic unity is therefore essential to our salvation. The Primates' policies are not "illegal", as Professor McCord Adams suggests, but, rather, rooted in the foundations of canon law. These are not, as for modern secular law, written procedural contracts, but the revealed scriptures as read with true inspired reason by the Church, along with its continuing mystical eucharistic formation.

If the Anglican Communion is authentically to be part of the international Church, it needs to see more fully the need for guidance by the wisdom of individuals and groups, and for charismatic decisions taken by bishops. Otherwise, it can only degenerate into a series of constitutional national bodies, teaching a diluted doctrine in the interest of secular state power.

Nevertheless, if we rightly put Anglican union at such a premium, we cannot logically stop there, but must pursue with redoubled vigour the reunion of all the episcopally based Catholic Christian Churches.

---Dr John Milbank is Professor of Religion, Politics, and Ethics at Nottingham University.