Don't be misled by the title of this book, nor by what others may have told you about it. In the first place, it isn't so much a book about 'Melancholy' (or abnormal psychology, or depression, or whatever) as a book about Burton himself and, ultimately, about humankind. Secondly, it isn't so much a book for students of the history of English prose, as one for lovers of language who joy in the strong taste of English when it was at its most masculine and vigorous. Finally, it isn't so much a book for those interested in the renaissance, as for those interested in life.
Burton is not a writer for fops and milquetoasts. He was a crusty old devil who used to go down to the river to listen to the bargemen cursing so that he could keep in touch with the true tongue of his race. Sometimes I think he might have been better off as the swashbuckling Captain of a pirate ship. But somehow he ended up as a scholar, and instead of watching the ocean satisfyingly swallowing up his victims, he himself became an ocean of learning swallowing up whole libraries. His book, in consequence, although it may have begun as a mere 'medical treatise,' soon exploded beyond its bounds to become, in the words of one of his editors, "a grand literary entertainment, as well as a rich mine of miscellaneous learning."
Of his own book he has this to say : "... a rhapsody of rags gathered together from several dung-hills, excrements of authors, toys and fopperies confusedly tumbled out, without art, invention, judgement, wit, learning, harsh, raw, rude, phantastical, absurd, insolent, indiscreet, ill-composed, indigested, vain, scurrile, idle, dull, and dry; I confess all..." But don't believe him, he's in one of his irascible moods and exaggerating. In fact it's a marvelous book.
Here's a bit more of the crusty Burton I love; it's on his fellow scholars : "Heretofore learning was graced by judicious scholars, but now noble sciences are vilified by base and illiterate scribblers."
And here is Burton warming to the subject of contemporary theologians : "Theologasters, if they can but pay ... proceed to the very highest degrees. Hence it comes that such a pack of vile buffoons, ignoramuses wandering in the twilight of learning, ghosts of clergymen, itinerant quacks, dolts, clods, asses, mere cattle, intrude with unwashed feet upon the sacred precincts of Theology, bringing with them nothing save brazen impudence, and some hackneyed quillets and scholastic trifles not good enough for a crowd at a street corner."
Finally a passage I can't resist quoting which shows something of Burton's prose at its best, though I leave you to guess the subject: "... with this tempest of contention the serenity of charity is overclouded, and there be too many spirits conjured up already in this kind in all sciences, and more than we can tell how to lay, which do so furiously rage, and keep such a racket, that as Fabius said, "It had been much better for some of them to have been born dumb, and altogether illiterate, than so far to dote to their own destruction."
To fully appreciate these quotations you would have to see them in context, and I'm conscious of having touched on only one of his many moods and aspects. But a taste for Burton isn't difficult to acquire. He's a mine of curious learning. When in full stride he can be very funny, and it's easy to share his feelings as he often seems to be describing, not so much his own world as today's.
But he does demand stamina. His prose overwhelms and washes over us like a huge tsunami, and for that reason he's probably best taken in small doses. If you are unfamiliar with his work and were to approach him with that in mind, you might find that (as is the case with Montaigne, a very different writer) you had discovered not so much a book as a companion for life.