Full Idea
Love is the extremely difficult realisation that something other than oneself is real.
Gist of Idea
Love is realising something other than oneself is real
Source
Iris Murdoch (The Sublime and the Good [1959], p.215)
Book Reference
Murdoch,Iris: 'Existentialists and Mystics', ed/tr. Conradi,Peter [Chatto and Windus 1997], p.215
A Reaction
I suspect that this is a necessary condition for love, but not the thing itself. The realisation she describes may not be love. You would attain her realisation if you shared a prison cell with a terrifying psychopath.