It is necessary to begin the story-line of our enquiry somewhere. And though it is always possible to take the story back historically beyond a chosen starting point, the primary interest of this study is systematic and conceptual, rather than historical. When I say, therefore, that a source for the Western Christian employment of the metaphors of darkness and light and of ascent and descent may be found in the impact of converging Greek and Hebraic influences on Western Christian thought, I have primarily in mind a deductive possibility, designed to shed light on an historical claim. I maintain, that is to say, that you could extract the main linguistic building blocks of the Western Christian tradition from the quarry of this convergence, and, even more particularly, that you could extract those building blocks from two stories, each foundational in the intellectual and religious cultures of its respective tradition: the ‘Allegory of the Cave’ in Book 7 of Plato's Republic, and the story in Exodus of Moses' encounter with Yahweh on Mount Sinai. You could do this: that is to say, with those two stories as premisses, you could satisfactorily derive much of the distinctiveness of the language of the Western Christian mystical tradition as conclusion.

Nevertheless, it is perfectly reasonable to go beyond a point merely in explanatory logic. There is little doubt that, whether it was the Greek cast of mind picking up the religious significance of Exodus in Platonic terms, or an Hebraic mind which seized upon the philosophical opportunities to be explored in Plato, this convergence did happen and was consciously acknowledged to have happened by theologians both of Greek and Latin traditions.

The language of interiority is a metaphorical discourse which at once structures Augustine's thought about selfhood, and organizes his personal sense of himself. It has, that is to say, both a conceptually and an experientially structuring power. As a metaphor it has no merely decorative purpose, nor in any other way could Augustine's understanding of self or of God survive its removal; nor are there any other terms to which that metaphor could be reduced.

This much I have tried to show in the last chapter. In this chapter we must raise some more detailed questions about how the metaphor articulates Augustine's thought, in particular about how the ‘inner’ as a category of thought and experience is to be distinguished from the ‘outer’ – for manifestly they are correlative, mutually defining, terms. Above all we must try to determine where the line of demarcation is meant to fall between the ‘inner’ and the ‘outer’: at what point do I cease to think or experience in an ‘outward’ way and begin to think or experience ‘inwardly’? And then we must ask how this discourse of inwardness relates with that other, complementary, discourse of ascent. We might say that if the last chapter was concerned with the dynamics of these metaphors, in this we will be concerned with their epistemological structure, their statics.

It would be a mistake to expect from Augustine any single, consistent and formal statement of how this distinction is to be made out even in any one work, let alone throughout his vast œuvre. Augustine's intellectual development is too exploratory, his temperament too tentative, for such expectations ever to be reasonable.

At the outset of our enquiry we need an explanation, if only of the most general sort, of two technical terms belonging to the vocabulary of late Platonist Christian theology, for without them the explanation of the purposes of this chapter is impossible. Those terms are ‘apophaticism’ and its complementary partner, ‘cataphaticism’. They have a technical sense, and it is a principal purpose of this essay to clarify that sense, or those senses, which they acquire within the Latin traditions of Neoplatonic mysticism, but for the immediate purpose of getting that discussion going, they can be given an accessibly non-technical explanation. ‘Apophaticism’ is the name of that theology which is done against the background of human ignorance of the nature of God. It is the doing of theology in the light of the statement of Thomas Aquinas in the thirteenth century, that ‘we do not know what kind of being God is’. It is the conception of theology not as a naive pre-critical ignorance of God, but as a kind of acquired ignorance, a docta ignorantia as Nicholas of Cues called it in the fifteenth century. It is the conception of theology as a strategy and practice of unknowing, as the fourteenth-century English mystic called it, who, we might say, invented the transitive verb-form ‘to unknow’ in order to describe theological knowledge, in this its deconstructive mode. Finally, ‘apophaticism’ is the same as what the Latin tradition of Christianity called the via negativa, ‘the negative way’. These are among the things which are meant by the term ‘apophaticism’.

In the middle of the fifteenth century, at the very end of the mediaeval period, Denys the Carthusian, a Flemish monk of extraordinary learning and of distinctly conservative theological disposition, looked back upon the preceding twelve hundred years of theological writing about ‘contemplation’ and attempted a compendious survey and an assessment. Denys' De Contemplatione is an eclectical work; it makes few claims to originality, but rather attempts to reconcile conflicting positions within the history of Patristic and mediaeval mystical writing. In particular he is concerned to effect a reconciliation on the issue which had so often preoccupied late mediaeval mystics, and as often distracted them from their main purposes: the issue of ‘intellectualist’ as against ‘Voluntarist’ accounts of ‘union with God’. For his own part Denys' acknowledged sources of influence are principally his namesake Denys the Areopagite and his compatriot Jan Van Ruusbroec. But what is of interest to us in this chapter is less the distinctiveness of Denys' theology – which admittedly is not great – than the character of De Contemplatione as a survey of the history of Western Christian mysticism in the Middle Ages; and this the more particularly since his interests, as ours have been, are focused upon the apophatic traditions of mediaeval Christian mysticism.

It is appropriate, though in an important way misleading, to open a discussion of Bonaventure's Itinerarium Mentis in Deum with an acknowledgement of his intellectual debts. ‘Bonaventure's work is regarded with good reason as the supreme example of mediaeval Augustinianism’, writes Grover Zinn, and in no work of Bonaventure's is this debt more manifest than in his Itinerarium. But if, as we will see, Bonaventure's Augustinianism is often filtered through the prism of an equally enthusiastic Augustinian of the twelfth century, Hugh of St Victor, the effect of Hugh's influence was to bring that Augustinianism into play with the other main stream of Christian Neoplatonism, the Dionysian. Zinn therefore adds: ‘This confluence of Augustinian and Dionysian materials in Hugh of St Victor's thought is most important for the development of theology, and especially in relation to Bonaventure.’

Having begun our discussion with extended reflections on these two great streams of Christian Neoplatonism, their convergence in Bonaventure gives him a pivotal importance for our discussion. But though it is appropriate to begin this chapter with a mention of Bonaventure's major sources, it is potentially misleading. For a reader of the Itinerarium, uninstructed in these and other, lesser sources, the most vivid impression will be of both the unity and coherence of thought, style and imagery and of the personal distinctiveness of Bonaventure's theology. Consequently, an analysis which did no more than to fragment this integrity into the multiplicity of its ‘influences’ – an effect of source-critical method which is always to be resisted – would miss the point, more particularly in this work than in many another, less integrated, text. Yet a compromise must be struck.

We have seen in Denys the Carthusian the emergence of what I have called ‘experientialism’, if only negatively in and through his resistance to it. Denys, however, is not familiar to a contemporary readership, whereas John of the Cross is all too familiar to it, to the point where the history of Western Christian ‘mystical theology’ is in some ways distorted by his prestige. It is, in any case, all too easy to read John of the Cross exclusively as an ‘early modern’ writer, to detach his work from its roots in the medieval tradition, and in no respect is this more likely, or more misleading, than in the tendency to characterize John's ‘modernity’ precisely by its ‘experientialism’. It cannot be wrong to see John as an ‘early modern’. It cannot be right, however, to neglect those respects in which John is deeply indebted to – that is to say, is thoroughly dependent upon – the mediaeval traditions of apophatic mysticism. And if ‘modernity’ is to be characterized by a preoccupation with the phenomena of the subjective and the experiential, then there is no doubt that in this respect John is a ‘modern’. On the other hand, if ‘experientialism’ is to be characterized by its translation of the dialectical categories of a Ncoplatonic theological epistemology into categories of subjective experience, then it is the argument of this chapter that John of the Cross is distinctly not an ‘experientialist’.

Our approach to the development of Western Christian apophatic theology has thus far been severely and narrowly textual, an approach which would have very little justification were our purposes otherwise than with theoretical issues, specifically of the relationship between a metaphorical discourse and the ontological and epistemological conditions of its employment; moreover, with theoretical issues raised by works in the genre of the ‘high’, technical theological treatise. Had our concerns been with popular piety and spirituality, or with texts written for specific readerships less academically equipped than were their authors, or with texts responsive to immediate and historically specific circumstances, it could not have been seriously proposed to examine them without reference to those historical contingencies. But since Denys and Augustine, Hugh of St Victor, Gallus and Bonaventure wrote their most influential works of spirituality without any conscious sense of occasion and as set-pieces intended to stand on their own, it has been at least possible, if not in every way desirable, to consider them in those terms in which they were written.

In the early fourteenth century, however, the apophatic tradition becomes for the first time in its long Christian history embodied in formulations which are regarded with suspicion of heresy. Though it is possible to consider these formulations without regard to their contemporary reception or to the historical conditions which determine it, it is rather less easy to justify doing so. Two cases stand out, those of Marguerite Porete and of Meister Eckhart.

The last chapter was concerned with one of the great issues of Eckhart's speculative metaphysics and theology. The purpose of this chapter is to approach Eckhart's theology from the ascetical end of the spectrum of his interests and to take up the subject of detachment, that is to say, the practice of apophatic anthropology. At any rate, the topics of these chapters are distinguished in so far as it is possible to distinguish between an ascetical topic and a speculatively theological one, for in Eckhart there is reason to doubt the value of this distinction. For my part I am disinclined to view Eckhart's writings, whether in the Latin or in the vernacular, either as those of one of the great practical spiritual teachers of the Western Christian tradition, or, alternatively, as those of a great speculative philosopher-theologian; or finally as writings which severally fall some in one category, some in the other. Rather, he belongs within a tradition which has wholly disappeared since the Middle Ages – indeed, perhaps since Eckhart himself – in which one could talk about all these things at once within a single, unified discourse and so could talk intelligibly about a ‘mystical theology’. It is not, however, appropriate yet to comment upon the disappearance of this tradition further than to recall how, in our meanings of the terms, the words ‘mystical’ and ‘theology’ pull apart from one another in opposed directions; and to guess that, as often as not, those directions appear to be as opposed as the ‘experiential’ and ‘speculative’ are: and that opposition increasingly concerns us in the rest of this book.

This book is an essay in the philosophical history of some theological metaphors. The metaphors – of ‘interiority’, of ‘ascent’, of ‘light and darkness’ and of ‘oneness with God’ – appear to have occupied a central role in the description of the Christian ways of spirituality for as long as Christians have attempted to give one. And they still do. There are many other metaphors – in particular, there are many metaphors of Christian love – whose role is equally crucial, but I have chosen to study the particular metaphors I have mentioned, and not others, for a number of reasons, among which the following are perhaps the most important.

First, because the metaphors of inwardness, ascent and light–darkness form a closely related cluster; secondly, because taken together they have an impact on the description of the Christian way of life which is distinctively ‘negative’ or ‘apophatic’, for which reason I have called them ‘metaphors of negativity’; thirdly, because they are metaphors characteristic of a Neoplatonic style of Christian theology, so that the study of them opens up lines of enquiry into an important aspect of the influence of Neoplatonism on Christian spirituality; fourthly, because they are metaphors which retain a currency still, and so it seemed that the study of them could also shed some light on what they do for us, by way of an account of the traditions from which we inherited them; and finally, this last reason seemed important to me because I suspected when I embarked on this study that the purposes which these metaphors serve for Christians today are very different from the purposes which they served within the ancient and mediaeval traditions of Christianity in the West, and that therefore it might be useful to know what those differences are.

It is time to calculate what gains have been made from the preceding discussion and to draw some conclusions. They appear to be the following.

First, in every author we have considered, the metaphors of ‘exteriority’, ‘inferiority’ and ‘ascent’ are central to the description of the progress of the soul towards God. Moreover, in all of them there is a more or less explicit recognition that that imagery must be employed ‘dialectically’ or as I have otherwise put it ‘self-subvertingly’. And we found that the metaphorical embodiment of that dialectic is most commonly that of the self-subverting imagery of the divine light which, through its very excess, causes darkness and unknowing to the soul; hence, in that most Platonic of images, it is a light which is also a darkness, a ‘dazzling darkness’, a ‘cloud of unknowing’.

Secondly, in the elucidation of the complexities of that dialectic it has seemed to me to be helpful to distinguish, first in Denys the Areopagite and subsequently in the others, between first- and second-order levels of description. Indeed, more than helpful; it seems that this distinction is necessary, and that even if it is not a distinction made as such by any of our authors, it is one implied in all the distinctions they do make. We, at least, need it if we are to read the mediaeval apophatic tradition adequately.

In this, his prologue to a translation of Denys' Mystical Theology, the Cloud Author rather puzzlingly claims both to have made a close rendering, following ‘the nakyd lettre of the text’ (which is far from true) and to have done so in accordance with the ‘sentence’ of Thomas Gallus, the thirteenth-century Abbot of St Andrew at Vercelli (which, for sure, he has). The Cloud Author thus at once makes clear that his indebtedness to Denys has been acquired through personal acquaintance with his writings and concedes that his reading of them is filtered through at least the century of Victorine interpretation which fed into Gallus, if not through the influence of others since that time.