Non-Muslims(Islamic) view of Ali(as)
Some non-Muslim scholars, like William Montgomery Watt and others do not accept narrations collected in later periods, and only study the early collections of narrations. This leads them to regard certain reported events as inauthentic or irrelevant, so that's why they rejected all hadith as fabrications, which colors their views. Others, like Wilferd Madelung, accept the hadith literature. A few of them, like L.Caetani, Lammens, have held a negative view of Ali. Madelung has criticized this school of thought and, like many other non-Muslim Islamic scholars have praised Ali a lot. Most modern non-Muslim scholars do not subscribe to the "Great Man" theory of the history and do not make judgments about historical figures like Ali.
Among events that Watt is dissmissive of, on the grounds that they are not included in what he calls "early sources" [meaning, essentially, the Sirat Rasul Allah of Muhammad(saw) ibn Ishaq] include:
Ali was prominent in the battlefield of Uhud and was wounded there seventeen times.
In 9 A.H. (630 CE), Muhammad prepared to lead an expedition against Syria. This was the well-known expedition of Tabuk. He left Ali behind in charge of Madinah, saying
"Will you not be pleased that you will be to me like Aaron to Moses? But there will be no prophet after me."
That this was the only battle Muhammad(saw) engaged in without Ali at his side.
"work with the narrative sources, both those that have been available to historians for a long time and others which have been published recently, made it plain that their wholesale rejection as late fiction is unjustified and that with [not without] a judicious use of them a much more reliable and accurate portrait of the period can be drawn than has so far been realized."
- Edward Gibbon
The zeal and virtue of Ali were never outstripped by any recent proselyte. He united the qualifications of a poet, a soldier, and a saint; his wisdom still breathes in a collection of moral and religious sayings; and every antagonist, in the combats of the tongue or of the sword, was subdued by his eloquence and valour. From the first hour of his mission to the last rites of his funeral, the apostle was never forsaken by a generous friend, whom he delighted to name his brother, his vicegerent, and the faithful Aaron of a second Moses. [The Decline and Fall of the Roman Empire, London, 1911, (originally published 1776-88) volume 5, pp. 381-2]
- Sir William Muir
Endowed with a clear intellect, warm in affection, and confiding in friendship, he was from the boyhood devoted heart and soul to the Prophet. Simple, quiet, and unambitious, when in after days he obtained the rule of half of the Moslem world, it was rather thrust upon him than sought. [The Life of Mahomet, London, 1877, p. 250]
- Dr. Henry Stubbe
He had a contempt of the world, its glory and pomp, he feared God much, gave many alms, was just in all his actions, humble and affable; of an exceeding quick wit and of an ingenuity that was not common, he was exceedingly learned, not in those sciences that terminate in speculations but those which extend to practice. [An Account of the Rise and Progress of Mahometanism, 1705, p. 83]
- Robert Durey Osborn
With him perished the truest hearted and best Moslem of whom Mohammadan history had preserved the remembrance. [Islam Under the Arabs, 1876, p. 120]
- Washington Irving
He was of the noblest branch of the noble race of Koreish. He possessed the three qualities most prized by Arabs: courage, eloquence, and munificence. His intrepid spirit had gained him from the prophet the appellation of The Lion of God, specimens of his eloquence remain in some verses and sayings preserved among the Arabs; and his munificence was manifested in sharing among others, every Friday, what remained in the treasury. Of his magnanimity, we have given repeated instances; his noble scorn of everything false and mean, and the absence in his conduct of everything like selfish intrigue. [Lives of the Successors of Mahomet, London, 1850, p. 165]
- Simon Ockley
One thing particularly deserving to be noticed is that his mother was delivered of him at Mecca, in the very temple itself; which never happened to any one else. [History of the Saracens, London, 1894, p. 331]
- Philip Khuri Hitti
Valiant in battle, wise in counsel, eloquent in speech, true to his friends, magnanimous to his foes, he became both the paragon of Muslim nobility and chivalry (futuwah) and the Solomon of Arabic tradition, around whose name poems, proverbs, sermonettes and anecdotes innumerable have clustered.”
- Wilferd Madelung
"In face of the fake Umayyad claim to legitimate sovereignty in Islam as God's Vicegerents on earth, and in view of Umayyad treachery, arbitrary and divisive government, and vindictive retribution, they came to appreciate his honesty, his unbending devotion to the reign of Islam, his deep personal loyalties, his equal treatment of all his supporters, and his generosity in forgiving his defeated enemies." [Book: Succession to Muhammad]
- Thomas Carlyle
"noble-minded...full of affection and fiery daring. Something chivalrous in him; brave as a lion; yet with a grace, a truth and affection worthy of Christian knighthood"
- Gerald de Gaury
Gerald opines that Ali was to be for ever the paragon of Muslim nobility and chivalry
- Charles Mills
As the chief of the family of Hashem and as the cousin and son-in-law of him whom the Arabians respected …, it is apparently wonderful that Ali was not raised to the Caliphate immediately on the death of Mohammad. To the advantages of his birth and marriage was added the friendship of the Prophet. The son of Abu Talib was one of the first converts to Islamism and Mohammad’s favourite appellation of his was the Aaron of a second Moses. His talents as an orator, and his intrepidity as a warrior, were grateful to a nation in whose judgement courage was virtue and eloquence was wisdom."
- United Nations
Nahj al-Balagha contains a long letter (letter 53) that contains instructions to Malik Ashtar, after he was appointed Governor of Egypt that how to establish and uphold a government: Never say to yourself, "I am their lord, their ruler and all in all over them and that I must be obeyed submissively and humbly". The United Nations urged the Arab nations to use that letter as a model.
Just mentioned their names as they did not give any proof from any good resources. I have listed these quotes so that you can also know how to treat such peoples. Wilferd criticizes such peoples by giving them authentic answers.
- L. Caetani
In his Annali dell' Islam Caetani levels severe criticisms against Ali's personality and policies. Wilferd Madelung in his Succession has provided a detailed critical analysis of these criticisms.
Lammens describes Ali as "dull-witted and incapable" in Scripta Pontificii Instituti Biblici