This thesis seeks to analyse what the word 'prophetic' means, in practice, and has identified the following as categories of activity within which prophetic endeavour is carried out, viz: compulsion to utter; call and commissioning; prophet as medium; authority; critical function; context; witness; task; sight; revelation; language and rhetorical persuasion; vocation; failure in mission; faithfulness and cost; burden and gift. An analysis of the prophetic activity and characteristics of some of the Hebrew Bible prophets instigated these criteria and the categories have been applied as a structural methodology to three poets: Gerard Manley Hopkins, R S Thomas, and William Blake, who lived and wrote within three different timeframes. One of these was a Priest, one a Minister, the other neither, but all were in their own unique ways with their prophetic 'poetry of protest' working both within and against organised and structured religion. Within this analysis therefore, this thesis seeks to articulate a chiasmus between poetry and prophecy as activities which explore the human realm, and between poets and prophets as inspired individuals working within and against wider society. The question of both divine revelation to and inspiration of these poet/prophets is a thorny one, and no attempt has been made to 'prove' the existence of these forces other than to accept, according to the personal testimony that has been left to us, the writers' experience of the a priori nature of these phenomena and their active presence within the articulation of vision. This exploration seeks to locate prophetic poetry within an already-existing arena where other interpreters have trodden, and accordingly the Chapter One Introduction reviews some ways in which others have approached the subject. However, with a grounding intention - an analysis in Chapter Two of some of the prophetic texts of the Hebrew Bible - this thesis carries the connection forward from other approaches into its own territory and seeks to locate prophetic utterance and prophetic characteristics within an identifiable and imposable structure of activity which could be applied to writers outwith the biblical canon, projecting the phenomenon of prophecy into the literary realm. Accordingly, Chapters Three, Four, and Five endeavour to analyse the ways in which the poets here discussed could be designated as prophets. Overall, the thesis proposes that there exists an underlying solum of prophecy as a diachronic phenomenon that can arise in synchronic form within ongoing human timescales, with the object of interjecting 'truths' by way of individual voices in specific times, from the eternal and ideal realm into the temporal and real world, in order to leave behind didactic imperatives to us that challenge and change our perspective and therefore our behaviour.