Dr Carmichael has produced a most valuable and scholarly book. She proceeds by organising her material in seven chapters, each including helpful introductions to her comprehensive group of writers. Readers are guided from the classical and New Testament world, through the western Latin tradition as far as Augustine, (with some attention to the east) and thence to the monastic world (Aelred) and Aquinas. A most interesting collection of contributors (Roman Catholic, Anglican, Reformers and philosophers) includes at last some sane and perceptive comment by women, and the whole moves to concluding reflections on God's friendship. Chapter 3–4 on Aelred and Aquinas probably say all that could be said on these two pivotal theologians. Turn to the end (p. 199) and we find the framework for the narrative: friendship-love, love of a friend, the kind of love one associates with a friend. The framework includes love as relationship, with friendship at its core. Such love is grounded in ‘shared being’, goodness expressing itself in action, other-directed with a view to fulfilment in joy. The ‘other’ may be God's creature or God, and Dr Carmichael might more forcefully have made the point that the Christian tradition's discomfort about the relationship between the two may have had its own part to play in disabling the determination to negotiate and renegotiate relationships between human beings, given the complexities of human circumstance, not least in marital and familial bonds.

Not only is hers the first book to pull together a wealth of material from the past and that from writers most of whom began their work hardly if at all knowing of one another's reflections, but she has spotted that the discussion of friendship is a genuinely new phenomenon in twentieth-century theology. Publication of hitherto often unavailable writing, ecumenism and the arrival of women theologians on the public scene since the 1980s have all made a difference. Female persons as friend-worthy are now more or less in focus though not yet inter-generational friendship, friendship between colleagues at work and even friendship with the non-human.

Notable achievements from a selection of the riches on offer in the book include not only that ‘the good person is a friend’ but in Aristotle a moment of recognition that maternal love may be an excellent example of active well-doing and even that in marriage (with the male superior) friendship might be possible. Friendship with a woman to whom one was not married, or friendships between women seem never to have been considered. Cicero was helpful on the way in which friends might sustain a good estimate of one's own proper worth, and the New Testament material reflects the evolution of Greek language (hence the critique of Nygren, p. 36). Agape emerges as Aristotle's ‘unnamed virtue’, i.e. the love which makes friendship possible, the reliable behaviour of an excellent friend. Augustine's focus on love directed towards God prompted him to a brilliant reinterpretation of the virtues as functions of such love – a decisive break with the classical tradition. And in a move of central importance for the more systematic treatment of the topic which Dr Carmichael acknowledges is needed, Augustine sees the virtues modelled in Christ with his exemplary humility and capacity for forgiveness. And we may note at this point the Johannine insight that Christ addresses his disciples as friends precisely at the juncture when he faces laying down his life for them.

From Aelred we may note the remarkable paragraph (p. 84) on the equality of female and male human beings, and his unique insight, as central in importance as Augustine's christological discernment, that friendship can lead to the knowledge and love of God (p. 88). Life on earth held open the possibility of offering experience of union between human beings, and not only with God in prayer, a perspective he shared with Maximus the Confessor. Rare indeed was Aelred's vision of eternal life as restored universal friendship: Deus amicitia est, and his insights were ignored, with the weight of negative attitudes to friendship within the monastic tradition shifting over into paradigms for lay holiness – a damaging legacy indeed.

Important contributions are then discernible in William of Auxerre's identification of faith, hope and love as virtues of God's gift, and his distinction between the kind of desire we may have for objects and the love and friendship we may have for persons whose good we desire and in whom we delight; and Abelard's discovery of disinterested love, born from the excruciating pain of his relationship with Heloïse. With Aquinas and his appropriation of Aristotle's Ethics when it arrived in the West, we find ‘body’ as an object of the friendship of caritas, given the distinct importance of a sacramentally related practice of the virtues by a person destined, perhaps, for re-creation in resurrection. The particularities of human friendship expand, as it were, into openness to all, because that is the way in which God loves, in whose friendship lies our happiness. Only in the twentieth century, however, were Aquinas' insights rediscovered (in the work of Häring and others pp. 127–8). In the aftermath of the distortions represented by a certain kind of ‘Thomism’, Aquinas' profound reflections on caritas may now contribute to a much-needed enrichment of Christian ethics where friendship should take its rightful place as a topic of great importance.

From chapter 7 we may appreciate the contributions of Mrs Katherine Phillips, one of Jeremy Taylor's friends and, at long last, Taylor's recognition of marriage as the locus of friendship above all – Taylor himself being the first major contributor on the subject to be himself married, and of course in an age where access to education was making a difference to how women might perceive themselves and be perceived. A Mrs Knowles rightly defended her own egalitarian Quaker tradition with vigour. The ‘Society of Friends’ may first have appeared in an anti-Quaker tract, but it is interesting, to say the least, not only that Quaker moves towards egalitarianism between women and men made such a label most appropriate, but that it should have issued in characteristically friend-like principles of behaviour. Food for thought, too, that it is a Baptist trinitarian theologian, James Houston, who produced a strongly recommended book The Transforming Friendship (1989) which includes a normative maxim, that ‘no one can be the friend of Jesus without having many other friends’. Among the many other invaluable suggestions to follow up are Helen Oppenheimer's attention to the ‘irreplaceability’ of human persons.

To conclude: if we were to take Augustine's christological point seriously, and ally it with James Houston's maxim, we would be some way to respond to Jürgen Moltmann's proposal (p. 2) that Christ himself be adored not only as Prophet, Priest and King but as Friend as well. At the other end of the book (pp. 191–2), Elisabeth Moltmann-Wendel moves in that direction in seeing God as friend as a healing and reconciling image, in which forgiveness and reconciliation are inextricably enjoined. Dr Carmichael writes her own brief for another book when she comments that no ‘christology of friendship’ would be likely to emerge until friendship itself was widely recognised as transfigured by Jesus’ actions. So we might conclude that if Augustine's christology were developed in the light of all the new understandings which are now available to us, Christian theology might well have something to offer in the matter of personal inter-and intra-relationality which was distinctive and, above all, would offer much to enhance human living.