I hate to say this,
because I think Herskovits was a really good anthropologist. But he was
not a very good philosopher.
Herskovits was very loose in his use of terms like 'valid' and he
never seems to have questioned the idea that the dominant values of a
culture are binding within it. Today, after the civil rights
movement and the women's movement, many people would question that.
Ruth Benedict made similar mistakes. She thought that morality was
simply another name for socially approved habits. I doubt that any
moral philosopher would agree. If it were true, none of us could
criticize the habits that are socially approved. After all, if what is
right in my culture is simply that which is socially approved, how
could I meaningfully and consistently say that the dominant (i.e.,
socially approved) view is mistaken or immoral? But we do this all the
time.