Revenge. Earlier in the character's history this was what many
thought but Batman's goal is not revenge. His goal is to make sure
no one else has to suffer what made him lose his childhood.
Crime.
Batman's goal it was to make people to fight for themselves.He
knew that Batman couldn't exist forever to save gotham,so he wanted
to raise up there courage to fight for gotham and help the one's
who can't defend thereselves.