It seems like this point of view is unassailable because for every example that, in regular understanding, would be selfless behaviour, the definition of self-interest is stretched to encompass it.
- Anonymous philanthropy => feelings of self worth
- Low reward public service (Mother Theresa) => fame and influence
- Parents sacrificing personal good for kids => some kind of evolutionary advantage
- Falling on a grenade => Avoiding survivors guilt
I don't mean to present strawman arguments for these scenarios - if they are silly I apologize. In any case, it seems to me that denial of altruism always ends up stretching the definition of selfish and shrinking the definition of selfless, so that any scenario can fit.
- Anonymous philanthropy => feelings of self worth
- Low reward public service (Mother Theresa) => fame and influence
- Parents sacrificing personal good for kids => some kind of evolutionary advantage
- Falling on a grenade => Avoiding survivors guilt
I don't mean to present strawman arguments for these scenarios - if they are silly I apologize. In any case, it seems to me that denial of altruism always ends up stretching the definition of selfish and shrinking the definition of selfless, so that any scenario can fit.