When Samuel Palmer praised Blake as ‘a man without a mask’, in August 1855, he was careful to include an account of his irascible temperament. There were, ‘some strange passages in his [Descriptive] Catalogue, written in irritation, and probably in haste’, and while, ‘No man more admired Albert Dürer; yet, after looking over a number of his designs, he would become a little angry with some of the draperies … materialism was his abhorrence: and if some unhappy man called in question the world of spirits, he would answer him … by putting forth his own views in their most extravagant and startling aspect’. One conspicuous object of Blake’s ‘irritation’ was, of course, William Hayley. Though other individuals were sometimes similarly subjected to what Swinburne called his “curious outbreaks of passionate dispraise and scorn”, they had given real grounds for offence—the Hunt brothers, for example, with their criticism of Blake’s 1809 exhibition or Richard Watson with his drily rational defence of orthodox Anglican theology. Hayley had done nothing so objectionable. Blake should have been grateful—and in letters to Hayley in 1804 and 1805 he was. But he denounced him in letters to his brother James Blake and his friend and patron Thomas Butts, mocked him in satirical verses in his Notebook, attacked him as ‘Hyle’ in Milton and Jerusalem, and (in one interpretation at least) condemned him as ‘Satan’ in the Bard’s Song episode of Milton. Were Blake’s denunciations of him justified? Or were they simply another instance of the irritation which Samuel Palmer remembered?