English writers talking about the Koran

Instead of a perpetual and perfect measure of the divine will, the fragments of the Koran were produced at the discretion of Mahomet; each revelation is suited to the emergencies of his policy or passion; and all contradiction is removed by the saving maxim, that any text of Scripture is abrogated or modified by any subsequent passage. The word of God, and of the apostle, was diligently recorded by his disciples on palm-leaves and the shoulder-bones of mutton; and the pages without order or connexion, were cast into a domestic chest in the custody of one of his wives.
Edward Gibbon, Decline and Fall of the Roman Empire, Chapter 50

Instead of inspiring the blessed inhabitants with a liberal taste for harmony and science, conversation and friendship, he [Mahomet] idly celebrates the pearls and diamonds, the robes of silk, palaces of marble, dishes of gold, rich wines, artificial dainties, numerous attendants, and the whole train of sensual and costly luxury, which becomes insipid to the owner, even in the short period of this mortal life. Seventy-two Houris, or black-eyed girls, of resplendent beauty, blooming youth, virgin purity, and exquisite sensibility, will be created for the use of the meanest believer; a moment of pleasure will be prolonged to a thousand years, and his faculties will be increased a hundred fold, to render him worthy of his felicity. Notwithstanding a vulgar prejudice, the gates of heaven will be open to both sexes, but Mahomet has not specified the male companions of the female elect, lest he should either alarm the jealousy of their former husbands, or disturb their felicity, by the suspicion of an everlasting marriage. 

Edward Gibbon, Decline and Fall of the Roman Empire, Chapter 50

If the composition of the Koran exceed the faculties of man, to what superior intelligence should we ascribe the Iliad of Homer or the Phillipics of Demosthenes?

Edward Gibbon, Decline and Fall of the Roman Empire, Chapter 50

I have no knowledge of either Sanscrit or Arabic. But I have done what I could to form a correct estimate of their value. I have read translations of the most celebrated Arabic and Sanscrit works. I have conversed, both here and at home, with men distinguished by their proficiency in the Eastern tongues. I am quite ready to take the oriental learning at the valuation of the orientalists themselves. I have never found one among them who could deny that a single shelf of a good European library was worth the whole native literature of India and Arabia.
Lord Macaulay, Minute on Education

I must say, it [the Koran] is as toilsome reading as I ever undertook. A wearisome confused jumble, crude, incondite; endless iterations, long-windedness, entanglement; most crude, incondite—insupportable stupidity in short!

Thomas Carlyle On Heroes, Hero-Worship, and The Heroic in History

It is a great shame for anyone to listen to the accusation that Islam is a lie and that Mahomet was a fabricator and a deceiver. We saw that he remained steadfast upon his principles, with firm determination; kind and generous, compassionate, pious, virtuous, with real manhood, hardworking and sincere. Besides all these qualities, he was lenient with others, tolerant, kind, cheerful and praiseworthy and perhaps he would joke and tease his companions. He was just, truthful, smart, pure, magnanimous and present-minded; his face was radiant as if he had lights within him to illuminate the darkest of nights; he was a great man by nature who was not educated in a school nor nurtured by a teacher as he was not in need of any of this.

Thomas Carlyle, On Heroes, Hero-Worship, and The Heroic in History. Actually the earliest information we have about the prophet's life is very late, as Gibbon pointed out in a footnote. It cannot be dated to less than two centuries after his supposed death. I explained why we know almost nothing for sure about his life and why I think we do know he really existed here.

It’s very one-dimensional, and people talk about the beauty of the Arabic and so on, but the English translation I read was, from a literary point of view, very dis­appointing. ...With the Koran there are no stories. And it has no ethical dimension like the New Testa­ment, no new plan for life. It says: ‘the Jews and the Christians were along the right tracks, but actually, they were wrong and I’m right, and if you don’t believe me, tough — you’ll burn for ever.’ That’s basically the message of the book.

Sebastian Faulkes in an interview in the Sunday Times, 2009.