He approved of assassination, when it furthered his cause; however barbarous or treacherous the means, the end justified it in his eyes; and in more than one case he not only approved, but also instigated the crime.
Concerning his moral character and sincerity, contradictory opinions have been expressed by scholars in the last three centuries.
He was a man of retiring disposition, addicted to prayer and fasting, and was subject to epileptic fits. His converts were about forty in all, including his wife, his daughter, his father-in-law Abu Bakr, his adopted son Ali Omar, and his slave Zayd.Nevertheless, with every allowance for exaggeration, Mohammed is shown by his life and deeds to have been a man of dauntless courage, great generalship, strong patriotism, merciful by nature, and quick to forgive.And yet he was ruthless in his dealings with the Jews, when once he had ceased to hope for their submission.He was affectionate and magnanimous, pious and austere in the practice of his religion, brave, zealous, and above reproach in his personal and family conduct.Palgrave, however, wisely remarks that "the ideals of Arab virtue were first conceived and then attributed to him".Maracci held that Mohammed and Mohammedanism were not very dissimilar to Luther and Protestantism.Spanheim and D'Herbelot characterize him as a "wicked impostor", and a "dastardly liar", while Prideaux stamps him as a wilful deceiver. Modern scholars, such as Sprenger, Noldeke, Weil, Muir, Koelle, Grimme, Margoliouth, give us a more correct and unbiased estimate of Mohammed's life and character, and substantially agree as to his motives, prophetic call, personal qualifications, and sincerity.He took the field against his enemies, conquered several Arabian, Jewish, and Christian tribes, entered Mecca in triumph in 630, demolished the idols of the Kaaba, became master of Arabia, and finally united all the tribes under one emblem and one religion.In 632 he made his last pilgrimage to Mecca at the head of forty thousand followers, and soon after his return died of a violent fever in the sixty-third year of his age, the eleventh of the Hejira, and the year 633 of the Christian era.According to them, Mohammed was simple in his habits, but most careful of his personal appearance. Of a highly nervous temperament, he shrank from bodily pain.Though gifted with great powers of imagination, he was taciturn.