The social circle of the painter Joshua Reynolds was remarkable even by the clubbable standards of Georgian London. Goldsmith, Fox, and Garrick were chums. Boswell dedicated a book to Reynolds. Edmund Burke executed his will. Having revolutionised British art education by founding the Royal Academy of Arts, he died in 1792, knighted and rich as a hog. He lives on in endless portraits of Georgian grandees and a series of lectures which have plagued art students ever since. They reveal a man of strong opinions, certain of his standing and of what constitutes artistic excellence. That question vexes us, but Sir Joshua was a son of the Enlightenment, empirical to his core. “What has pleased and continues to please,” he declares, “is likely to please again; hence are derived the rules of art, and on this immovable foundation they must ever stand.”

　　Pleasingly enough, the great teacher’s most famous student was one he barely noticed, William Blake. Obscure in life, dying in poverty, Blake has had the most glorious artistic afterlife imaginable. His apotheosis is an inspiration to mad bastards everywhere. In April, the National Gallery of Ireland brings us an exhibition to confirm what an odd duck he was, William Blake: The Age of Romantic Fantasy.

　　In Cambridge last year, a trigger warning for another Blake exhibition promised, “depictions of suffering, sexual violence and enslavement.” The Guardian’s review lamented that Blake, “is clearly a racist by modern standards.” As you can imagine, tickets sold out quickly. In an increasingly domesticated world, the appeal of this artistic wild man is obvious.

　　The Age of Romantic Fantasy is a compilation of the Tate’s Blake collection that has been touring Europe for a few years. It comes now from Turin to Dublin. To see some of the cranky cockney’s best-known works hanging alongside paintings of contemporaries will be a reminder that artistic reputations are fleeting.

　　In the late eighteenth century, when young Blake was practicing drawing in the Royal Academy, the world’s finest sculpture was known to be the Apollo Belvedere. It was the standard by which contemporary sculptors like Canova and Flaxman were judged. A cast of it was amongst the plasters Royal Academy students were obliged to study. Copying such masterpieces was the way for neophytes to hone their craft and, just as vital, to imbibe good taste. Today, the Apollo’s star has dimmed. It gets hardly a glance from the crowds that pour through the Vatican Museum each morning to gawp at the Sistine Chapel. The serenity and order that appealed to the Neoclassicists leave us cold. The Grand Style championed by Joshua Reynolds is considered pompous. The art we prefer is disorderly, expressive, and rarely in good taste. That revolution is one reason why William Blake, a radical possessed by apocalyptic visions and wild fancies, has so eclipsed his peers.

　　It is not obvious why. Many of the artists that curator Anne Hodge has chosen to hang with Blake are better draftsmen. The figures painted by Irishman James Barry are more naturalistic.John Hamilton Mortimerand J. M. W. Turner are better painters. The “Romantic Fantasy” promised in the exhibition’s subtitle is abundantly found in Henry Fuseli. And Blake’s fellow Londoner Rowlandson was a more prolific and popular print maker—in life at least.

　　So what accounts for Blake’s august standing today? His figures are often clumsy and crude. His colours can be distracting and downright ugly. His poetry, regularly obscure to the point of unintelligibility, has similar defects. At its worst, it has a sing-song quality of doggerel coupled with an annoying earnestness. Scanning a line as inane as “The Caterpillar on the Leaf / Repeats to thee thy Mother’s grief” brings one up short. The pathetic tiger with which Blake illustrated his most famous verse inspires similar dismay. As G. K. Chesterton said, “Blake could do so many things. Why is it that he could do none of them quite right?”

　　For all that, Blake’s reputation is deserved. He is much more than the sum of his parts. He is not the only great artist to write or great writer to draw—Cellini, Van Gogh, Victor Hugo, and Sylvia Plath could do both well—but none of them expresses the same unique personality so powerfully in both mediums. Blake’s deceptively simple poetry has an aphoristic quality that is mirrored in his boldly graphic prints. Their blazing originality refutes Joshua Reynolds’ dictum that, “What has pleased and continues to please is likely to please again.” Blake pleases in a way no one has ever quite done before or since.

　　There is no better example of that originality in this exhibition than Cain Fleeing from the Wrath of God. Cain has been discovered in the act of burying his slain brother. He is a heroic nude, in the style of Blake’s hero Michelangelo. There is no attempt at realism in the setting. The background is reduced to shapes and colour like a minimalist theatre set. And that theatricality extends to the hammy gestures of the characters. With medieval fervour, Eve swoons over her dead son. Adam glares at the fleeing fugitive. The murderer’s face is a mask of tragedy. He tears his hair in grief. Above his head hover flames. We are witnessing not just the aftermath of a sordid crime but a moment of cosmic significance. 

　　Blake is, quite obviously, the most Christian poet since Milton, the most Christian artist since Michelangelo. Truly madly deeply, Blake believes.

　　Even as Blake apes Michelangelo, the contrast with his artistic idol was never starker. The Italian was an effortless draftsman; Blake’s every stroke is agonised. Yet much as the Sistine Chapel astounds, it does not move us as Blake’s painfully wrought visions do. To call Blake an idiot savant would be unfair, but he certainly struck many sophisticated contemporaries as naïve. They saw well-worn biblical tales as opportunities to show off their skills; Blake treats them as sacraments. And it works. The laconic drama of the Pentateuch springs to life with raw emotion. We feel the full horror of fratricide, the crime that makes the Earth bleed, and condemn Cain anew.

　　This timeless quality eventually raised Blake far above his contemporaries, earning him a legion of champions from Coleridge to T. E. Lawrence. Most admirers attempt to remake Blake in their own image. Pre-Raphaelites seeking to imbue their painting with a medieval purity saw Blake as an exemplar. William Butler Yeats convinced himself that Blake was Irish nobility. That theory is not taken seriously, but Yeats’ notion of Blake the Occultist still has currency in pop culture. To 1950s Beatniks, Blake became an apostle of free love. The author Philip Hoare has recently argued that James Joyce “deploys Blake’s queerness like a grenade in Ulysses and Finnegans Wake.” The National Gallery has even invited Hoare to Dublin to apply this fashionable frame to their exhibition. Modern curators are oddly keen to repackage Blake (happily married to Catherine Boucher for 45 years) as a genderfluid, “poet of the queer brotherhood.”

　　The elephant nobody cares to mention is Blake’s Christianity. He is, quite obviously, the most Christian poet since Milton, the most Christian artist since Michelangelo. Truly madly deeply, Blake believes. It’s safe to say that a man who regularly conversed with ghosts would have been a mystic no matter what station of life he was born into. Still, it is no surprise that religious attitudes in this era were affected by class. Blake’s family was not only lower middle class; they were also devotees of the theologian Swedenborg. On that base of eccentric mysticism, Blake built his highly individual faith. To be sure, his Christianity is uniquely nonconformist and rooted in the Old Testament. A true dissenter, he disdained the Church of England, “And Priests in black gowns, were walking their rounds, / And binding with briars, my joys desires.” Indeed, anyone with the power to say “Thou shalt not” earns Blake’s suspicion. Even God. Blake’s work is full of bearded patriarchs who look like they have been sleeping rough—Nebuchadnezzar, Ezekiel, and the Ancient of Days all need a cup of coffee and a shower. Blake had daddy issues. His beef with authority extended to King George III. He celebrated America throwing off her “heavy iron chains,” he wore a bonnet rouge when the French Revolution began, and was even tried for sedition in 1803. 

　　But the biggest chip on William Blake’s shoulder was “the Oppression of Sr Joshua his Gang of Cunning Hired Knaves.” I recall a collection of Reynolds’ Royal Academy lectures being pressed into my hands as a student in Florence. I thumbed through the pages, searching for the secret sauce, the wisdom from on high to fast-track me to artistic virtuosity. Reynolds’ advice, though sound, was underwhelming: practice. I paraphrase, of course. Georgian gents take their time saying everything. “If you have great talents,” he counsels, “industry will improve them. … Excellence is never granted to man, but as the reward of labour.” As an example of that excellence, he cites the “grace of the Apollo [Belvedere]” and defends its proportions.

　　These judgments and strictures did not ring as tyrannical to my young ears as they did to William Blake’s. In the book’s appendix, I smiled to read Blake’s opinion on the lectures: “The following Discourse is particularly Interesting to Blockheads.” The erratic capitalisation, vocabulary, and spelling date these marginalia, but anyone who has had an overbearing teacher, boss, or spouse will instantly recognise the relish Blake takes in privately rebutting Reynolds’ platitudes. “I do not believe this Anecdote … O Shame False … This Whole Book was Written to Serve Political Purposes … Is not this a Manifest Lie … The Following sentence is Supremely Insolent … This is all False Self-Contradictory … Contemptible Mocks … Damn The Fool Never! This must be how Liars Reason … Infernal Falshood … There is no End to the Follies of this Man … The Mind that could have produced this Sentence must have been Pitiful … Abundance of Stupidity … Here is Nonsense!”

　　Yes, Blake was the antithesis of Reynolds, lacking the tact and manners of a courtier, but this unrestrained spleen does not accord with Blake’s popular reputation for saintly unworldliness. It gives us instead a vivid sense of why this humourless, blunt man could not long keep a patron. Admirers and romantics will argue that no one could create as Blake did without feeling so strongly, but this is more than artistic disagreement. Envy is at play. It irks Blake that Sir Joshua died “rolling in Riches” while he, the pure artist true to his genius, goes unrecognised and unrewarded.

　　But even in his private bile, Blake is honest. When Reynolds says something wise, he grudgingly acknowledges it. “A Noble Sentence. … Well said. … These remarks on Poussin are Excellent.” And, in the middle of this strange one-sided argument, there is a throwaway remark that illuminated Blake’s unique interior life. “The Man who never in his Mind Thoughts traveld to Heaven Is No Artist.” This exhibition is an opportunity to see the treasures this irascible English genius brought back from that celestial journey.