Quote Originally Posted by TexasBob View Post
If you define altruism in a way that is self-contradictory then you need a better definition.

This is one of those "you know it when you see it" things. Mother Teresa was not just being selfish in a clever way. If we have trouble categorizing her behavior that's our shortcoming not a proof of her character flaw. If we can't come up with something better we could define altruism to mean "whatever Mother Teresa would do".
Altruism is helping someone, at a cost to you, and gaining nor expecting anything in return.

I don't have trouble categorizing her behavior, she helped people because she enjoyed it and she would have been morally compromised if she hadn't.

If you can't find a behavior that fits, that doesn't mean there is a flaw in the definition.