There’s a moment in Pauli Murray’s book about her family, “Proud Shoes,” where she expresses shock at learning as she dug through genealogical records that one of her great-grandfathers, Thomas Fitzgerald, had indeed once been a slave. Fitzgerald lived most of his life as a free man, but his past had been carefully concealed from his descendants, it seemed, out of shame. At learning this, Murray wrote: “I would always be in rebellion… until people no longer needed legends about their ancestors to give them distinctiveness and self-respect.” Murray’s stories still provide ample material for the debates of our time on race, heritage and identity. Gone are the old iron-clad divisions when it comes to race. But the old battlegrounds have been scattered via pop culture to a larger world, resulting in new fights and possibly, new walls. For instance, if you have a black father and a white mother, are you black or are you white? That is apparently still a much-debated question. When Paris Jackson, daughter of pop icon Michael Jackson, said she …