Everything everyone ever does can be viewed as self-interested in the appropriate lens, but it's for precisely the same reason that that lens doesn't give you more information on how to predict people's behaviour.

A father risks his life to save his daughter. Did he do it for his daughter? Or did he do it because it made him feel better? Or to avoid feeling terrible if he didn't act? Or because genetics compels him to take care of offspring sharing, on average, 50% of his genetic distinctiveness?

There may be a causal chain in these things, genetics -> love -> joy of helping, fear of loss from not helping -> acting on behalf of another.

But we lose much of our descriptive, analytic and predictive powers if we insist on only looking at what we think are the first movers in this chain. It's not productive to try and predict the weather on the basis of quantum theory; for practicality, we look at the system at higher levels of abstraction, with their own conceptual bundles, and yes, their own names.

So I can agree with you that, in the most facile and base senses, altruism is not a "proper virtue", and that humans are "intrinsically self-interested". But I can also say that some humans are more altruistic than others, and that some humans are less self-interested than others, because saying these things expresses more information than trying to describe how one human seems to have a causal chain whose self interest leads him to seem paradoxically less self-interested and more altruistic, etc. etc.

In other words, I'm talking about personality at the conceptual level of personality, using its generally accepted meanings of words, rather than pedantically hammering away at first principles of selfishness.

Perhaps a more complete definition of altruism would be this: you are altruistic to the degree that your personal welfare is driven by your observations of the welfare of those around you, and the level of action you take as a result.

This satisfies both the commonplace meaning and the annoying but correct sophomoric objection.

It all adds up to normality.

One can also cause damage from being selfish. I'm not sure what your point is, no one's claiming that just wanting to help people is good enough. You have to actually help people.

> I also believed that humans are intrinsically self-interested even if human beings couldn't exist without other human beings. No man is an island but every man is an individual worthy of respect and dignity.

Agreed to an extent, and your last point is why a lot of altruists want to help the poor and downtrodden instead of just the individuals they happen to like. It's a straw-man form of "altruism" that treats individuals as scum.