Karen Armstrong is a British author of numerous works on comparative religion, who first rose to prominence with her highly successful History of God. A former Catholic nun, she asserts that "All the great traditions are saying the same thing in much the same way, despite their surface differences." They each have in common, she says, an emphasis upon the overriding importance of compassion, as expressed by way of the Golden Rule: Do not do unto others as you would not have done unto you.

Author of several books on the Muslim tradition, she has, since 9/11, become much in demand on the US lecture circuit. In February 2008, Armstrong called for the drawing up of a Charter of Compassion, a global interfaith initiative which, she announced, already enjoyed the support of the likes of Archbishop Desmond Tutu and the United Nations.