Thomas Carlyle.

The famous historian, Thomas Carlyle, in his book “Heroes and Hero worship”, refers to this misconception about the spread of Islam: “The sword indeed, but where will you get your sword? Every new opinion, at its starting is precisely in a minority of one. In one man’s head alone. There it dwells as yet. One man alone of the whole world believes it, there is one man against all men. That he takes a sword and try to propagate with that, will do little for him. You must get your sword! On the whole, a thing will propagate itself as it can.”