They do not relate to the present any more than they relate to the person.
I came across this sentence from the book The Fire Next Time and just couldn’t understand it. Than would indicate some sort of comparison, but it's not a construction I've come across before.
How do I interpret “they do not X any more than they Y”?
A fuller context that may be more helpful here:
The person who distrusts himself has no touchstone for reality—for this touchstone can be only oneself. Such a person interposes between himself and reality nothing less than a labyrinth of attitudes. And these attitudes, furthermore, though the person is usually unaware of it (is unaware of so much!), are historical and public attitudes. They do not relate to the present any more than they relate to the person. Therefore, whatever white people do not know about Negroes reveals, precisely and inexorably, what they do not know about themselves. [from page 57 of The Fire Next Time, see the Goodreads quotes page ]