This thesis considers William Langland’s engagement with sacramenta, natural signs which manifest some semblance of the divine nature within the created universe. It makes the distinctive claim that the sacramental theology of Piers Plowman is interwoven with its natural theology, and that this relationship is the key to understanding the narrator’s epistemic progress across the poem. I argue that Will’s ability to draw supernatural knowledge from natural signs at the rhetorical climax of the narrative is the fruit of an epistemic journey led by grace and participation in the sacraments of the Church. For Hugh of St Victor, a key figure in the history of sacramental theology, all of creation was thought to have some ‘sacramental’ significance that humans might be drawn to interpret mystically or allegorically. This idea has its origins in Christian Platonism, including Alexandrian logos theology. It found its most influential expositor in pseudo-Dionysius who married the Platonist ideas of ontological participation and the natural mystical sign with the ecclesial sacraments of Christian ritual. Both Hugh and Dionysius conceived of the ritual sacraments as mediators of man’s relationship with God and particularly of man’s ability to perceive God within the natural order.

The introduction outlines my overarching argument and explains some of the central claims of medieval sacramental theology alongside their scriptural sources. It also explores biographical and historical question which are foundational to my arguments about philosophical influence. It critically synthesises existing debates about Langland’s identity and reaches the conclusion that the author of Piers Plowman was probably a clerk in minor orders. Sources for Langland’s learning are postulated in the light of this identification, which increases the likelihood that he encountered sacramental theology. As well as reviewing existing secondary research, it presents new bibliographical evidence on the circulation of works of pastoral theology.

Chapter two establishes that three crucial ideas are carried over from Dionysius into medieval sacramental theology: ontological participation, sacramental mediation, and the natural mystical sign (or ‘natural sacrament’). This account of the Christian Platonist tradition reveals the interconnectedness of natural and sacramental theology. It shows that these ideas were transmitted to the late Middle Ages, especially by Hugh of St Victor. Another strand of the chapter is its identification of Augustinian ideas about creation and the nature of evil that I later argue are reflected in Langland’s pessimism about cognitive faculties.

In chapter three, I argue that the current settled critical view that Langland has a Chartrian theology of nature is misguided. Among other objections, I highlight that Langland is too sceptical about the ability of the fallen intellect to ‘read’ nature, and this is at odds with the more optimistic Chartrian outlook. I see Langland’s view of nature as a synthesis of Augustinian pessimism about the effects of the Fall and Dionysian optimism about the redemptive power of the sacraments. This synthesis matches Hugh’s integration of Augustine and Dionysius in his De sacramentis.

In chapter four, I substantiate these claims further with a close study of Langland’s theology of nature as it is presented through his personification Kynde. My reading emphasises that Langland is attentive to the negative epistemic consequences of the Fall when he writes about nature, and that his narrator cannot adequately comprehend God in nature with his own unguided faculties. Even outside of the degenerative effects of the Fall, there remains the metaphysical problem of the ontological gap that stands between creator and creation, which means that a primarily intellectual pursuit of God in nature is likely to prove fruitless.

At this stage, I argue that Langland’s Dionysian and Victorine sacramentalism provides an answer to his pessimism about Fallen nature (which was explored in chapter four). It shows that nature can be redeemed by grace channelled through material signs. It also offers an alternative explanation for how humans might ‘read’ nature, one that locates this capability in participation and the mediation of signs (in contrast to the intellectualist Chartrian view rejected in chapter three). It addresses the problem of the ontological gap through mediation and grace. Chapter five thinks about the restorative power of Penitence encountered by Will and a very similar figure called Hawkyn (B.XIII-XIV). It also considers the inner experience of sacramental participation which involves the will, affect, grace and virtue – especially the virtue of patientia which is dramatised by Langland’s character Patience.

Chapter six argues that the narrator’s participatory engagement with Penitence has restored Will’s ability to see God in nature. Just as Dionysius, and later Hugh of St Victor, had suggested the natural mystical signs of the world could be elucidated through participation in the ecclesial sacraments, so Will now finds the ability to discern the Trinity in natural objects. The climax of my thesis is a close reading of what I take to be the poem’s theological and sacramental zenith: a revelation of the Trinity through analogic interpretations of the human hand and fire (in B.XVII). Before I reach this natural sacramental moment, I look at the interlude between the reception of the ecclesial sacrament (B.XIII-XIV) and the revelation of God in nature. Here, I emphasise the need to cooperate with grace in order to participate in the sacrament; something I take to be allegorised by the ‘Tree of Charity’ sequence. Patientia remains important here, but so is caritas. This is a supernatural love kindled by grace which enables the penitent to remain in a state of grace. The attention to the mechanics of grace in Piers Plowman reflects the influence of Hugh of St Victor and later pastoralia on Langland. Although the influence of Dionysian Platonism is crucial to my argument, I also believe that Langland engaged with these ideas in the light of later works of theology that have their own independent emphases.

As well as looking back over this epistemic journey, my conclusion comments on the Dionysian ideas of apophasis and cataphasis. It suggests that they can help us to appreciate the role of the apparently impenetrable mystery of the true definition of Dowel, Dobet, and Dobest. I conclude by reflecting on my methodology and the advantages to engaging with the History of Philosophy in literary scholarship.