"Common descent in Darwin's younger day was ubiquitous in anti-slavery tracts. Consider the words of the famous cameo, depicting a kneeling slave asking "Am I Not a Man and a Brother?" That cameo was in fact the brainchild of the pottery-dynasty founder, Josiah Wedgwood, Darwin's grandfather. New evidence shows how indebted Darwin was to this anti-slavery heritage. Darwin knew that going into print would have invited derision" - Michael Muller