Voltaire, Rousseau, Henri de Boulainvilliers and Napoleon all commented on Prophet Muhammad. The Enlightenment in France had changed the way they thought of him.
Islamic scholars have traditionally categorized the enemies of Islam during the time of Prophet Muhammad (salAllahu alayhi wa sallam) into two categories. The first are those who vehemently opposed Islam, to the point where they were willing to sacrifice their own pre-Islamic values in their efforts to put down Prophet Muhammad, his followers, and his mission. In this category one may find, for example, Abu Jahl ibn Hishām or Umayyah ibn Khalaf, and they along with many others in this category perished in the Battle of Badr. But in the second category were those who opposed Islam and persecuted/fought the Muslims but they remained noble in character and held on to certain admirable pre-Islamic values, not trampling all over them in trying to subdue the Islamic movement. In this category one may find, for example, Khālid ibn al-Walīd or ‘Amr ibn al-‘Ās, and even ‘Umar ibn al-Khattāb (radiAllahu anhum ajma‘īn). It is noteworthy that Allah (subhānahu wa ta‘āla) eventually guided most, if not all, of the people in this category to Islam. 
Another area of historical study where this categorization of the opponents of Islam can be applied is in the perception of Prophet Muhammad (salAllahu alayhi wa sallam) in European intellectual thought. For most of European history after the dawn of Islam, Prophet Muhammad has been demonized by Christian scholars, including the famous reformer Martin Luther, for example. This has not been because a critical understanding of the Prophet’s life was acheieved by European intellectuals – for the most part, they didn’t even try. Thus, more often than not it was preferable to them (and “they” at this time was the Roman Catholic Church) to utterly demonize Prophet Muhammad, because by doing so they could pinpoint him as the man who embodied everything that they, as Christians living the tough life in medieval Europe, ought to hate about the Muslims, be they Muslims in Spain, Sicily, or Anatolia.
By the 18th century, however, the situation had changed drastically. Muslims were no longer the rulers of Spain or Sicily, and even in Anatolia the power of the once feared Ottoman Empire was starting to decline. But even more importantly, the Renaissance (c. 14th-17th centuries) and Protestant Reformation (c. 1517-1648) had occurred in Europe, leaving the Roman Catholic Church with a lot less influence over the European population than it once had. Intellectuals could now independently challenge beliefs that had been unquestioned in European society for centuries, and the long-held negative perception of Prophet Muhammad (salAllahu alayhi wa sallam) in Europe finally began to be challenged as well. This period of intellectual rethinking came to be known as the Age of Enlightenment (c. 1620s-1780s), and was particularly popular in France (where it would culminate in the French Revolution in 1789).
Henri de Boulainvilliers (1658-1722) was a French nobleman and historian, inspired by the famous philosophers René Descartes and John Locke, and an Enlightenment-era intellectual who wrote on physics, philosophy, theology and, of course, on history. In one of his more famous works, titled Vie de Mahomed (The World of Muhammad), he defended Prophet Muhammad against common allegations that he was inspired by a Christian assistant, that his doctrine was irrational, and that he was an imposter. Instead, Henri argued, Muhammad was a divinely-inspired messenger whom God had sent to liberate the Near East from the despotic rule of the Romans and Persians and to spread the message of tawhīd, or God’s indivisible unity, from India to Spain. Muhammad’s success, said Henri, was such that it “could only be from God.” About Islam, Henri said that Muhammad’s doctrine merely removed all that was irrational and undesirable about Christianity as it was practiced at the time. Muhammad “seems to have adopted and embraced all that is most marvelous in Christianity itself,” wrote Henri, “so that what he retrenched, relates obviously to those abuses alone, which it was impossible he should not condemn.” Henri de Boulainvilliers’ work was banned in Catholic France but was published in 1730, after his death, in Protestant Amsterdam and London. 
Henri de Boulainvilliers’ historical representation of Prophet Muhammad (salAllahu alayhi wa sallam) had an effect on other Enlightenment-era thinkers, particularly the French philosopher Voltaire (1694-1778). Voltaire, a renowned poet, essayist, playwright and also a historian, is most famous for his attacks on the established Roman Catholic Church, his advocacy of freedom of religion and of expression, and his advocacy of secularism. His opposition to Islam and his demonization of Prophet Muhammad, however, was carried out even more vehemently than his attacks on the Church and the Pope. In 1736, he wrote a play called Le Fanatisme, ou Mahomet le Prophete (Fanaticism, or Muhammad the Prophet) and it was first staged in 1741. As the name suggests, it portrayed the Prophet as “an impostor desiring self-glorification and beautiful women who is willing to lie, to kill, and even to wage war against his homeland to get what he desires.”  He expressed similar views about the Prophet in two of his letters, one to Frederick II of Prussia in 1740 and the other to Pope Benedict XIV in 1745. Sometime after 1745, however, he read Boulainvilliers’ Vie de Mahomed, and it seems to have had a lasting impact on his perception of Prophet Muhammad (salAllahu alayhi wa sallam). Later in life, particularly in his historical writings such as the Essay on the Customs and the Spirit of the Nations (1756), Voltaire praised the Prophet as an effective and tolerant leader and a successful conqueror, though he still maintained that Prophet Muhammad was not divinely inspired but was “so carried away [by his success as a leader] that he believed himself inspired by God.” 
Jean-Jacques Rousseau (1712-1778) was yet another Enlightenment-era French philosopher who couldn’t help but comment on Prophet Muhammad (salAllahu alayhi wa sallam), and that too in his magnum opus, The Social Contract (1762). Muhammad, he said, was neither an imposter nor a sorcerer, but an admirable legislator who successfully combined spiritual and worldly power.  In 1787, Claude-Emmanuel Pastoret (1755-c. 1830), a French author and politician, published his Zoroaster, Confucius and Muhammad, in which he compared and contrasted the careers of the three Eastern religious “great men”, “the greatest legislators of the universe.” He defended Prophet Muhammad against the allegations commonly made against him, and praised the Qur‘ān for the way it upholds the unity of God (tawhīd). 
Henri de Boulainvilliers, Voltaire, Jean-Jacques Rousseau and Claude-Emmanuel Pastoret all lived during the Enlightenment and all were French intellectuals, but Napoleon Bonaparte (1769-1821), another Frenchman who was very interested in Prophet Muhammad (salAllahu alayhi wa sallam), came to the stage after the French Revolution and is remembered far more as a military and political leader than as an intellectual or historian. In May 1798, he set out towards the Egypt and Syria leading 55,000 men of the French navy in an effort to challenge British control over the area, which was officially still part of the Ottoman Empire. On July 1, 1798, before landing at Alexandria, he sent the following written declaration to the Egyptian people:
“In the name of God the Beneficent, the Merciful. There is no other God than God, [and] He has neither son nor associate to His rule. On behalf of the French Republic founded on the basis of liberty and equality, the General Bonaparte, head of the French Army, proclaims to the people of Egypt that for too long the beys [i.e. Ottoman governors] who rule Egypt insult the French nation and heap abuse on its merchants; the hour of their chastisement has come. For too long, this rabble of slaves brought up in the Caucasus and in Georgia [i.e. the ruling-class Mamluks of Egypt] tyrannizes the finest region of the world; but God, Lord of the worlds, [the] All-Powerful, has proclaimed an end to their empire. Egyptians, some will say that I have come to destroy your religion. This is a lie, do not believe it! Tell them that I have come to restore your rights and to punish the usurpers; that I respect, more than do the Mamluks, God, His prophet Muhammad and the glorious Qur‘ān… Qādī, shaykh, shorbagi, tell the people that we are true Muslims. Are we not the one who has destroyed the Pope [during the Italian Campaign of 1796-97] who preached war against Muslims? Did we not destroy the Knights of Malta, because these fanatics believed that God wanted them to make war against the Muslims?” 
This definitely sounds very much like the self-serving, propagandistic rhetoric that is always used by imperialists, but it shows Napoleon’s cultural and historical awareness and the way he used it to his advantage. It also shows that, far from vilifying Prophet Muhammad (salAllahu alayhi wa sallam) and trying to convince the Egyptian people that Islam was the cause of the tyrannical leadership from which he was supposedly here to liberate them, he actually used Islam to legitimize his cause. But nevertheless, this was most probably mere lip service. But many years later, as he was exiled to the remote island of Saint Helena after having lost the Napoleonic Wars, he wrote down his thoughts on Prophet Muhammad in his memoirs. Since there was no conceivable ulterior motive by this point for him to be saying about Prophet Muhammad what he did not actually believe, the following passage from his memoirs may show his genuine admiration for Prophet Muhammad:
“Arabia was idolatrous when Muhammad, seven centuries after Jesus Christ, introduced the cult of the God of Abraham, Ishmael, Moses and Jesus Christ. The Arians and other sects that had troubled the tranquility of the Orient had raised questions concerning the nature of the Father, the Son and the Holy Spirit. Muhammad declared that there was one unique God who had neither father nor son; that the trinity implied idolatry. He wrote on the frontispiece of the Qur‘ān: “There is no other god than God.”
He addressed savage, poor peoples, who lacked everything and were very ignorant; had he spoken to their spirit, they would not have listened to him. In the midst of abundance in Greece, the spiritual pleasures of contemplation were a necessity; but in the midst of the deserts, where the Arab ceaselessly sighed for a spring of water, for the shade of a palm where he could take refuge from the rays of the burning tropical sun, it was necessary to promise to the chosen, as a reward, inexhaustible rivers of milk, sweet-smelling woods where they could relax in eternal shade, in the arms of divine hūrīs with white skin and black eyes. The Bedouins were impassioned by the promise of such an enchanting abode; they exposed themselves to every danger to reach it; they became heroes. Muhammad was a prince; he rallied his compatriots around him. In a few years, his Muslims conquered half the world. They plucked more souls from the false gods, knocked down more idols, razed more pagan temples in fifteen years, than the followers of Moses and Jesus Christ did in fifteen centuries. Muhammad was a great man.” 
“Muhammad was a great man.” Boulainvilliers, Rousseau and Pastoret would definitely agree, though none of them are known to have ever practiced Islam. ‘Umar, Khālid, and ‘Amr would definitely agree as well, whether you asked them before they embraced Islam or afterwards. But what do all of them have in common? The answer, I would argue, was their enlightened, which provided them with certain values which shaped their understanding of the life of Prophet Muhammad (salAllahu alayhi wa sallam). They lived during periods of uncertainty and major social and intellectual shake-ups of society. The Frenchmen all lived during the Enlightenment, and so they challenged the traditional way of thinking about Prophet Muhammad using their shifting values (a shift towards objectivity when studying history, for example). The Arabs, for their part, were all relatively young at the time of the dawn of Islam, and therefore were not as caught up in the traditions of pre-Islamic Arabia as their elders were, so they challenged the traditional way of thinking about Prophet Muhammad as well, using their own shifting values (a shift from tribal identity to faith-based identity, for example).
The reminder in this for Muslims today is that not all those who oppose Islam do so for the same reason or in the same way. There are always certain trends, yes, but Muslims should remain keenly aware of non-Muslim individuals who are attaining enlightenment through social, cultural and intellectual shifts, because these shake-ups in history often present excellent opportunities for fulfilling the obligation of da’wah to Islam. ‘Umar, Khālid, and ‘Amr all received this da’wah; Boulainvilliers, Voltaire, Rousseau, Pastoret and Napoleon almost certainly did not. And we will never know, given their general admiration for the Prophet, how close these enlightened French disbelievers may have been to embracing Islam if only they had been properly invited to it.
- Yasir Qadhi, “Seerah of Prophet Muhammed 3 – Why study the Seerah? & Pre-Islamic Arabia”, YouTube video, June 22, 2012, https://www.youtube.com/watch?v=4F5qzMI2IKs.
- Henri de Boulainvilliers, La vie de Mahomed (Amsterdam: P. Humbert, 1730); Boulainvilliers, The Life of Mahomet (London: W. Hinchliffe, 1731), 179-222.
- John Tolan, “European Accounts of Muhammad’s Life”, in Jonathan Brockopp (Ed.), The Cambridge Companion to Muhammad (New York: Cambridge University Press, 2010), 241.
- Voltaire, Essai sur les moeurs, chap. 6.
- Jean-Jacques Rousseau, Du contrat social (Amsterdam: Marc Michel Rey, 1762), 303–304.
- Emmanuel Pastoret, Zoroastre, Confucius et Mahomet, comparés comme sectaires, législateurs, et moralistes; avec le tableau de leurs dogmes, de leurs lois et de leur morale (Paris: Buisson, 1787), 385, l. 1 and 234-236.
- Qtd. in Henri Laurens, L’Exp´edition d’Egypte, 1798–1801 (Paris: Seuil, 1997), 108.
- Napoléon Bonaparte, Campagnes d’Egypte et de Syrie (Paris: Imprimerie Nationale, 1998), 140-141.
Image: Napoleon in Egypt (1863) by Jean-Léon Gérôme (https://s-media-cache-ak0.pinimg.com/originals/f4/f3/41/f4f3415ec2e9bb7913c4d67931082bb7.jpg)