John T., Having the documented proof and making assumptions or best guess, based upon information that one currently has is the major difference. I believe that you will also find in the book a statement that references the "family legend" of Abraham Adam and David being brothers but no real proof had been found. At this time I am not in a position to state with confidence that Abraham Adam is the son of Abraham, Sr. or Jacob. The same applies to David. Until we find additional information that will help to determine this, I will continue to maintain that the parents of Abraham Adam and David are unknown and whether or not David and Abraham Adam are brothers would still be a question. John Walter