Here are some quotes about Prophet Mohammed (PBUH) as described by some Non-Muslim Intellectuals of their time.
Thomas Carlyle in 'Heroes and Hero Worship and the Heroic in History' 1840
"The lies (Western slander) which well-meaning zeal has heaped round this man (Muhammad) are disgraceful to ourselves only."
"A silent great soul, one of that who cannot but be earnest. He was to kindle the world, the world’s Maker had ordered so."
A. S. Tritton in 'Islam,' 1951
The picture of the Muslim soldier advancing with a sword in one hand and the Qur'an in the other is quite false.
De Lacy O'Leary in 'Islam at the Crossroads,' London, 1923.
History makes it clear, however, that the legend of fanatical Muslims sweeping through the world and forcing Islam at the point of sword upon conquered races is one of the most fantastically absurd myths that historians have ever repeated.
Gibbon in 'The Decline and Fall of the Roman Empire' 1823
The good sense of Muhammad despised the pomp of royalty. The Apostle of God submitted to the menial offices of the family; he kindled the fire; swept the floor; milked the ewes; and mended with his own hands his shoes and garments. Disdaining the penance and merit of a hermit, he observed without effort of vanity the abstemious diet of an Arab.
Edward Gibbon and Simon Oakley in ‘History of the Saracen Empire,’ London, 1870
"The greatest success of Mohammad’s life was effected by sheer moral force."
“It is not the propagation but the permanency of his religion that deserves our wonder, the same pure and perfect impression which he engraved at Mecca and Medina is preserved after the revolutions of twelve centuries by the Indian, the African and the Turkish proselytes of the Koran....The Mahometans have uniformly withstood the temptation of reducing the object of their faith and devotion to a level with the senses and imagination of man. ‘I believe in One God and Mahomet the Apostle of God’ is the simple and invariable profession of Islam. The intellectual image of the Deity has never been degraded by any visible idol; the honors of the prophet have never transgressed the measure of human virtue, and his living precepts have restrained the gratitude of his disciples within the bounds of reason and religion.”
Reverend Bosworth Smith in 'Muhammad and Muhammadanism,' London, 1874.
"Head of the State as well as the Church, he was Caesar and Pope in one; but he was Pope without the Pope's pretensions, and Caesar without the legions of Caesar, without a standing army, without a bodyguard, without a police force, without a fixed revenue. If ever a man ruled by a right divine, it was Muhammad, for he had all the powers without their supports. He cared not for the dressings of power. The simplicity of his private life was in keeping with his public life."
"In Mohammadanism every thing is different here. Instead of the shadowy and the mysterious, we have history....We know of the external history of Muhammad....while for his internal history after his mission had been proclaimed, we have a book absolutely unique in its origin, in its preservation....on the Substantial authority of which no one has ever been able to cast a serious doubt."
Edward Montet, 'La Propagande Chretienne et ses Adversaries Musulmans,' Paris 1890. (Also in T.W. Arnold in 'The Preaching of Islam,' London 1913.)
"Islam is a religion that is essentially rationalistic in the widest sense of this term considered etymologically and historically....the teachings of the Prophet, the Qur'an has invariably kept its place as the fundamental starting point, and the dogma of unity of God has always been proclaimed therein with a grandeur a majesty, an invariable purity and with a note of sure conviction, which it is hard to find surpassed outside the pale of Islam....A creed so precise, so stripped of all theological complexities and consequently so accessible to the ordinary understanding might be expected to possess and does indeed possess a marvelous power of winning its way into the consciences of men
Mahatma Gandhi, statement published in 'Young India,'1924.
I wanted to know the best of the life of one who holds today an undisputed sway over the hearts of millions of mankind.... I became more than ever convinced that it was not the sword that won a place for Islam in those days in the scheme of life. It was the rigid simplicity, the utter self-effacement of the Prophet the scrupulous regard for pledges, his intense devotion to his friends and followers, his intrepidity, his fearlessness, his absolute trust in God and in his own mission. These and not the sword carried everything before them and surmounted every obstacle. When I closed the second volume (of the Prophet's biography), I was sorry there was not more for me to read of that great life.
Alphonse de LaMartaine in 'Historie de la Turquie,' Paris, 1854.
"Never has a man set for himself, voluntarily or involuntarily, a more sublime aim, since this aim was superhuman; to subvert superstitions which had been imposed between man and his Creator, to render God unto man and man unto God; to restore the rational and sacred idea of divinity amidst the chaos of the material and disfigured gods of idolatry, then existing. Never has a man undertaken a work so far beyond human power with so feeble means, for he (Muhammad) had in the conception as well as in the execution of such a great design, no other instrument than himself and no other aid except a handful of men living in a corner of the desert. Finally, never has a man accomplished such a huge and lasting revolution in the world, because in less than two centuries after its appearance, Islam, in faith and in arms, reigned over the whole of Arabia, and conquered, in God's name, Persia Khorasan, Transoxania, Western India, Syria, Egypt, Abyssinia, all the known continent of Northern Africa, numerous islands of the Mediterranean Sea, Spain, and part of Gaul.
"If greatness of purpose, smallness of means, and astonishing results are the three criteria of a human genius, who could dare compare any great man in history with Muhammad? The most famous men created arms, laws, and empires only. They founded, if anything at all, no more than material powers which often crumbled away before their eyes. This man moved not only armies, legislations, empires, peoples, dynasties, but millions of men in one-third of the then inhabited world; and more than that, he moved the altars, the gods, the religions, the ideas, the beliefs and the souls.
"On the basis of a Book, every letter which has become law, he created a spiritual nationality which blend together peoples of every tongue and race. He has left the indelible characteristic of this Muslim nationality the hatred of false gods and the passion for the One and Immaterial God. This avenging patriotism against the profanation of Heaven formed the virtue of the followers of Muhammad; the conquest of one-third the earth to the dogma was his miracle; or rather it was not the miracle of man but that of reason.
"The idea of the unity of God, proclaimed amidst the exhaustion of the fabulous theogonies, was in itself such a miracle that upon it's utterance from his lips it destroyed all the ancient temples of idols and set on fire one-third of the world. His life, his meditations, his heroic revelings against the superstitions of his country, and his boldness in defying the furies of idolatry, his firmness in enduring them for fifteen years in Mecca, his acceptance of the role of public scorn and almost of being a victim of his fellow countrymen... This dogma was twofold the unity of God and the immateriality of God: the former telling what God is, the latter telling what God is not; the one overthrowing false gods with the sword, the other starting an idea with words.
"Philosopher, Orator, Apostle, Legislator, Conqueror of Ideas, Restorer of Rational beliefs.... The founder of twenty terrestrial empires and of one spiritual empire that is Muhammad. As regards all standards by which human greatness may be measured, we may well ask, is there any man greater than he?"
Reverend Bosworth Smith in 'Muhammad and Muhammadanism,' London, 1874.
"Head of the State as well as the Church, he was Caesar and Pope in one; but he was Pope without the Pope's pretensions, and Caesar without the legions of Caesar, without a standing army, without a bodyguard, without a police force, without a fixed revenue. If ever a man ruled by a right divine, it was Muhammad, for he had all the powers without their supports. He cared not for the dressings of power. The simplicity of his private life was in keeping with his public life."
"In Mohammadanism every thing is different here. Instead of the shadowy and the mysterious, we have history....We know of the external history of Muhammad....while for his internal history after his mission had been proclaimed, we have a book absolutely unique in its origin, in its preservation....on the Substantial authority of which no one has ever been able to cast a serious doubt."
Edward Montet, 'La Propagande Chretienne et ses Adversaries Musulmans,' Paris 1890. (Also in T.W. Arnold in 'The Preaching of Islam,' London 1913.)
"Islam is a religion that is essentially rationalistic in the widest sense of this term considered etymologically and historically....the teachings of the Prophet, the Qur'an has invariably kept its place as the fundamental starting point, and the dogma of unity of God has always been proclaimed therein with a grandeur a majesty, an invariable purity and with a note of sure conviction, which it is hard to find surpassed outside the pale of Islam....A creed so precise, so stripped of all theological complexities and consequently so accessible to the ordinary understanding might be expected to possess and does indeed possess a marvelous power of winning its way into the consciences of men."