From the author’s footnote to Anecdotes – Juvenal in v.1 of Thomas de Quincey’s Posthumous Works:
‘The passion which made Juvenal a poet.‘ The scholar needs no explanation; but the reader whose scholarship is yet amongst his futurities (which I conceive to be the civilest way of describing an ignoramus) must understand that Juvenal, the Roman satirist, who was in fact a predestined poet in virtue of his ebullient heart, that boiled over once or twice a day in anger that could not be expressed upon witnessing the enormities of domestic life in Rome, was willing to forego all pretensions to natural power and inspiration for the sake of obtaining such influence as would enable him to reprove Roman vices with effect.