Muhammad is not the father of any of your men, but he is the Messenger of God and the Last of the Prophets. (Holy Qur'an 33:40)
This is a collection of short quotations from a wide variety of Non-Muslim notables, including academics, writers, philosophers, poets, politicians, and activists belonging to the East and the West.
To our knowledge none of them ever became Muslims. These words, therefore, reflect their personal views on various aspects of the life of the Prophet.