David Mitchell said this quote

“ What if the differences between social strata stem not from genomics or inherent xcellence or even dollars, but merely differences in knowledge? Would this not mean the whole Pyramid is built on shifting sands? I speculated such a suggestion could be seen as a serious deviancy. Melphi seemed delited. Try this for deviancy: fabricants are mirrors held up to purebloods' consciences; what purebloods see reflected there sickens them. So they blame you for holding up the mirror. I hid my shock by asking when purebloods might blame themselves. Melphi relplied, History suggests, not until they are made to. ”