Love of mankind; charity (12)
I believe the answer is:
philanthropy
I believe this clue is a double definition.
'love of mankind' is the first definition.
(I've seen this before)
'charity' is the second definition.
(I know that philanthropy is a type of charity)
(Other definitions for philanthropy that I've seen before include "beneficial treatment" , "Practical benevolence" , "Altruism" , "Generous deeds" , "The donating of money to good causes" .)