The tragedy of Karbala decided not only the fate of the caliphate, but of the Mohammedan kingdoms long after the Caliphate had waned and disappeared. - William Muir

Neither their (the Muslims') tenets nor their practice will in any respect bear to come into competition with Christian, or even with Jewish morality. ... For instance, we call the Muslims chaste because they abstained from indiscriminate profligacy, and kept carefully within the bounds prescribed as licit by their Prophet. But those bounds besides the utmost freedom of divorce and change of wives, admitted an illimitable licence of cohabitation with 'all that the right hand of the believer might possess,' or, in other words, with any possible number of damsels he might choose to purchase, or receive in gift, or take captive in war.

The sword of Mahomet and the Coran are the most fatal enemies of civilization, liberty, and truth which the world has yet known.

But of this genera of writing, William Muir's The Life of Mahomet, first published in 1861 in four volumes, was the best. It was a pioneering study and it has not been improved upon since then. William Muir had strong Christian views but he was also a painstaking and conscientious researcher, and he exhausted most of the sources on the Prophet's life, which were not many. The basic material on Muhammad is limited and new biographies could not really be new except in details, treatment and emphases.