Cicero claimed 'When a man thinks of a true friend, he is looking at himself in the mirror'.
'Greater love hath no man than this, that he lay down his life for his friends' (John 15:13).
Professor Justin Champion considers what friendship meant to the early Christian scholars.
Francis Bacon wrote 'Those that want friends to open themselves unto, are cannibals of their own hearts'.
Justin Champion ponders the notion of friendship in the 21st century.