The classical Anglican case for modesty and reserve in Trinitarian doctrine

Where exactly, one might wonder, did they acquire such a vivid feeling for the inner life of the deity?

So said Karen Kilby in her influential paper critiquing social Trinitarianism, 'Perichoresis and Projection: Problems with Social Doctrines of the Trinity'. Particularly significant is Kilby's sense that social Trinitarianism is placing too great a burden on Trinitarian teaching, making the doctrine hold and say much more than it can sustain:   

I began by noting a concern in recent theology to re-establish the vitality and relevance of the doctrine of the Trinity, and in fact I think it is here that the whole thing actually starts to go wrong. Does the Trinity need to be relevant? What kind of relevance does it need to have? The doctrine of the Trinity arose in order to affirm certain things about the divinity of Christ, and, secondarily, of the Spirit, and it arose against a background assumption that God is one.  So one could say that as long as Christians continue to believe in the divinity of Christ and the Spirit, and as long as they continue to believe that God is one, then the doctrine is alive and well; it continues to inform the way they read the Scriptures and the overall shape of their faith.  But clearly many theologians are wanting something in addition to this, something beyond this, some one particular insight into God that this particular doctrine is the bearer of. It is when one gets to thinking about three being one, and how this might be possible, that most Christians grow puzzled, silent, perhaps even uninterested, and this is what so many theologians are troubled by.

This leads to a conclusion radically opposed to the social Trinitarianism's supposed 'recovery' of the doctrine of the Trinity.  Social Trinitarianism, Kilby declares, has put too great an emphasis on the doctrine of the Trinity:

The doctrine of the Trinity, I want to suggest, does not need to be seen as a descriptive, first order teaching - there is no need to assume that its main function must be to provide a picture of the divine, a deep understanding of the way God really is.  It can instead be taken as grammatical, as a second order proposition, a rule, or perhaps a set of rules, for how to read the Biblical stories, how to speak about some of the characters we come across in these stories, how to think and talk about the experience of prayer, how to deploy the “vocabulary” of Christianity in an appropriate way.  The doctrine on this account can still be seen as vitally important, but important as a kind of structuring principle of Christianity rather than as its central focus: if the doctrine is fundamental to Christianity, this is not because it gives a picture of what God is like in se from which all else emanates, but rather because it specifies how various aspects of the Christian faith hang together.

Kilby's challenge to the social Trinitarian claim to "a deep understanding of the way God really is", and instead proposing the Trinity as a "grammatical ... second order proposition", brings to mind an earlier Anglican tradition of urging a modesty and reserve in Trinitarian doctrinal claims.  Consider, for example, this extract from a Tillotson sermon:

So that to baptize "in the name of the Father, and of the Son, and of the Holy Ghost", is to perform this rite or sacrament by the authority of, and with special relation to, the three persons of the blessed Trinity, Father, Son, and Holy Ghost, as the chief objects of the Christian faith, whereof solemn profession was then made. So that upon this form of baptism, appointed by our Saviour, compared with what is elsewhere said in Scripture, concerning the divinity of the Son, and the Holy Ghost, is principally founded the doctrine of the blessed Trinity; I mean in that simplicity in which the Scripture hath delivered it, and not as it hath been since confounded and entangled in the cobwebs and niceties of the schools. The Scripture, indeed, nowhere calls them persons, but speaks of them as we do of several persons; and therefore that word is not unfitly used to express the difference between them, or at least we do not know a fitter word for that purpose (Volume VI of The Works of Tillotson, Sermon CXXIII).

Tillotson's concern for avoiding excessive claims about the Trinity, claims which lead to being "confounded and entangled in the cobwebs and niceties of the schools" with their speculations about the inner life of God, is also to be found in Taylor:

He that goes about to speak of and to understand the mysterious Trinity, and does it by words and names of man's invention, or by such which signify contingently, if he reckons this mystery by the mythology of numbers, by the cabala of letters, by the distinctions of the school, and by the weak inventions of disputing people; if he only talks of essences and existences, hypostases and personalities, distinctions without difference, and priority in co-equalities, and unity in pluralities, and of superior predicates of no larger extent than the inferior subjects, he may amuse himself, and find his understanding will be like S. Peter's upon the mount of Tabor at the transfiguration: he may build three tabernacles in his head, and talk something, but he knows not what. But the good man that feels the power of the Father, and he to whom 'the Son is become wisdom, righteousness, sanctification, and redemption'; he 'in whose heart the love of the Spirit of God is spread', to whom God hath communicated the 'holy Ghost, the Comforter'; this man, though he understands nothing of that which is unintelligible, yet he only understands the mysteriousness of the holy Trinity. No man can be convinced well and wisely of the article of the holy, blessed, and undivided Trinity, but he that feels the mightiness of the Father begetting him to a new life, the wisdom of the Son building him up in a most holy faith, and the love of the Spirit of God making him to become like unto God.

He that hath passed from his childhood in grace under the spiritual generation of the Father, and is gone forward to be a young man'in Christ, strong and vigorous in holy actions and holy undertakings, and from thence is become on old disciple, and strong and grown old in religion, and the conversation of the Spirit; this man best understands the secret and undiscernible economy, he feels this unintelligible mystery, and sees with his heart what his tongue can never express, and his metaphysics can never prove. In these cases faith and love are the best knowledge, and Jesus Christ is best known by the grace of our Lord Jesus Christ; and if the kingdom of God be in us, then we know God, and are known of Him; and when we communicate of the Spirit of God, when we pray for Him, and have received Him, and entertained Him, and dwelt with Him, and warmed our selves by His holy fires, then we know Him too. But there is no other satisfactory knowledge of the blessed Trinity but this; and therefore whatever thing is spoken of God metaphysically, there is no knowing of God theologically, and as He ought to be known, but by the measures of holiness, and the proper light of the Spirit of God (Volume VIII of The Works of Taylor, 'Via Intelligentiae; a sermon preached to the University of Dublin').

There is, then, classical Anglican precedent for Kilby's proposal to moderate theological claims regarding the Trinity.  Both Tillotson and Taylor urge, in particular, against excessive metaphysical claims for Trinitarian doctrine, pointing instead - as does Kilby - to the Trinity as a means of interpreting our experiences of reading Scripture and prayer.  Doubting, as they do, that scholastic discourse on the Trinity meaningfully contributes to the life of faith, they suggest something akin to Kilby's claim that most Christians are rightly "uninterested" in such speculations. Taylor and Tillotson also articulate a view not unlike Kilby's statement that beyond affirming the deity of Son and Spirit, and confessing that God is One, Christians need no further Trinitarian language: hence Tillotson's "that simplicity in which the Scripture hath delivered it" and Taylor's "this man, he understands nothing of that which is unintelligible, yet he only understands the mysteriousness of the holy Trinity".  

Following Taylor and Tillotson, we have grounds for heeding Kilby's call for significantly greater modesty and reserve in Trinitarian claims than much recent theology has recognised, understanding that confessing the Trinity is not dependent upon answering the speculative questions of "the schools", for - as Kilby states - the meaning of the confession 'three persons, one substance' is "a secondary question".