Hopkins began his time in Oxford as a keen socialiser and prolific poet, but he seems to have alarmed himself with the changes in his behaviour that resulted, and he became more studious and began recording his sins in his diary. In particular, he found it hard to accept his sexuality; hence, he began to exercise strict self-control in regard to it, especially after he became a follower of Henry Parry Liddon and of Edward Pusey, the last, lingering member of the original Oxford Movement. It was during this time of intense scrupulosity that Hopkins seems to have begun confronting his strong homoerotic impulses. (See section below on Erotic influences)
In 1866, following the example of John Henry Newman, he converted from Anglicanism to Roman Catholicism. After his graduation in 1867 Hopkins was provided a teaching post by Newman, but the following year he decided to enter the priesthood, pausing only to visit Switzerland, which officially forbade Jesuits to enter.
Hopkins's attempts at poetry began at an early age, influenced by his father's own attempts at the art. His decision to become a Jesuit led him to burn much of his early poetry as he felt it incompatible with his vocation. Writing would remain something of a concern for him as he felt that his interest in poetry prevented him from wholly devoting himself to his religion. He continued to write a detailed journal until 1874. Unable to suppress his desire to describe the natural world, he also wrote music, sketched, and for church occasions he wrote some "verses," as he called them. He would later write sermons and other religious pieces. While he was studying in the Jesuit house of theological studies, St Beuno's, near St Asaph in North Wales, he was asked by his religious superior to write a poem to commemorate the foundering of a German ship in a storm. So in 1875 he was moved to take up poetry once more and write a lengthy poem, The Wreck of the Deutschland. This work was inspired by the Deutschland incident, a naval disaster in which 157 people died including five Franciscan nuns who had been leaving Germany due to harsh anti-Catholic laws (see Kulturkampf). The work displays both the religious concerns and some of the unusual meter and rhythms of his subsequent poetry not present in his few remaining early works. It not only depicts the dramatic events and heroic deeds but also tells of the poet's reconciling the terrible events with God's higher purpose. The poem was accepted but not printed by a Jesuit publication, and this rejection fuelled his ambivalence about his poetry. Most of his poetry remained unpublished until after his death.
Hopkins chose the austere and restrictive life of a Jesuit and was at times gloomy. The brilliant student who had left Oxford with a first class honours degree failed his final theology exam. This failure almost certainly meant that, though ordained in 1877, Hopkins would not progress in the order. Though rigorous and sometimes unpleasant, his life during Jesuit training had at least some stability; the uncertain and varied work after ordination was even harder on his sensibilities. In 1874 he returned to Manresa House to teach classics. He then went to St Beuno's College in North Wales for three years of theological studies. He served in various parishes in London, Chesterfield, Oxford, Liverpool and Glasgow. He taught Greek and Latin at Mount St Mary's College, Sheffield, and Stonyhurst College, Lancashire. In 1884 he became professor of Greek literature at University College Dublin. His English roots and his disagreement with the Irish politics of the time, as well as his own small stature (5'2"), unprepossessing nature and own personal oddities meant that he was not a particularly effective teacher. This as well as his isolation in Ireland deepened his gloom and his poems of the time, such as I Wake and Feel the Fell of Dark, reflected this. They came to be known as the "terrible sonnets," not because of their quality but because according to Hopkins's friend Canon Dixon, they reached the "terrible crystal," meaning that they crystallized the melancholy dejection which plagued the latter part of this life.
Though he suffered from what today might be diagnosed as manic depression, and battled a deep sense of anguish throughout his life, upon his death bed, he evidently overcame some of his feelings of despondency, at times stygian in their intensity. His last words were "I am so happy, I am so happy."
Hopkins is commemorated by a blue plaque in Roehampton, London.
He uses many archaic and dialect words, but also coins new words. One example of this is twindles, which seems from its context in Inversnaid to mean a combination of twines and dwindles. He often creates compound adjectives, sometimes with a hyphen (such as dapple-dawn-drawn falcon) but often without, as in rolling level underneath him steady air. This concentrates his images, communicating the instress of the poet’s perceptions of an inscape to his reader.
Hopkins was influenced by the Welsh language that he acquired while studying theology at St Beuno's College near St Asaph. The poetic forms of Welsh literature and particularly cynghanedd with its emphasis on repeating sounds accorded with his own style and became a prominent feature of his work. This reliance on similar sounding words with close or differing senses mean that his poems are best understood if read aloud. An important element in his work is Hopkins's own concept of "inscape" which was derived, in part, from the medieval theologian Duns Scotus. The exact detail of "inscape" is uncertain and probably known to Hopkins alone but it has to do with the individual essence and uniqueness of every physical thing. This is communicated from an object by its "instress" and ensures the transmission of the item's importance in the wider creation. His poems would then try to present this "inscape" so that a poem like "The Windhover" aims to depict not the bird in general but instead one instance and its relation to the breeze. This is just one interpretation of probably Hopkins's most studied poem and one which he called his best.
During his lifetime, Hopkins published few poems. It was only through the efforts of Robert Bridges that his works were seen. Despite Hopkins burning all his poems on entering the Jesuit novitiate, he had already sent some to Bridges who, with a few other friends, was one of the few people to see many of them for some years. After Hopkins's death they were distributed to a wider audience, mostly fellow poets, and in 1918 Bridges, by then poet laureate, published a collected edition; an expanded edition, prepared by Charles Williams, appeared in 1930, and a greatly expanded edition by W. H. Gardiner appeared in 1948 (eventually reaching a fourth edition, 1967, with N. H. Mackenzie).
Hopkins was completely taken with Dolben, who was nearly four years his junior, and his private journal for confessions the following year proves how absorbed he was in imperfectly suppressed erotic thoughts of him
He pursued Dolben during the course of their correspondence, writing about him in his diary and composing two poems about the youth, "Where art thou friend" and "The Beginning of the End." Robert Bridges, who edited the first edition of Dolben's poems as well as Hopkins's, cautioned that the second poem "must never be printed," though Bridges finally decided to include it in the first edition (1918). Another indication of the nature of his feelings for Dolben is that Hopkins's High Anglican confessor seems to have forbidden him to have any contact with Dolben except by letter. Their relationship was abruptly ended by Dolben's drowning in June 1867, an event from which Hopkins never fully recovered: "Ironically, fate may have bestowed more through Dolben’s death than it could ever have bestowed through longer life ... [for] many of Hopkins’s best poems — impregnated with an elegiac longing for Dolben, his lost belovèd and his muse — were the result.
Some of his poems, such as "The Bugler's First Communion" and "Epithalamion", embody homoerotic themes, and he has been associated recently with the Uranian poets, whose writings derived, in many ways, from the prose works of Walter Pater, Hopkins's academic coach for his Greats exams, and later his lifelong friend.