"We cannot be tied beyond our strength and meanes. The reason is, because the effects and executions are not any way in our power,and except our will, nothing is truly in our power: on it onely are all the rules of man's dutie grounded and established by necessitie."
(Michel de Montaigne, Essays; you can find the whole essay here.)
Hence, we should consider the purpose behind the action rather than the consequences.
Recently I have been exposed to a careless person - not that I am not careless myself, but I try my best. The problem with this person is that in its self-indulgence he does not even realize how bad his lack of consideration is affecting those who surround him. I was really mad at him because the results of his lack of concern (not returning calls, not thinking about others, etc.) where the same ones as those of a selfish person. But given that it is the reason behind the act - the lack of act in this case - what must be taken into account and not the act itself, I know I should not be mad at him.