Historian John Burton states In judging the content, the only resort of the scholar is to the yardstick of probability, and on this basis, it must be repeated, virtually nothing of use to the historian emerges from the sparse record of the early life of the founder of the latest of the great world religions ... so, however far back in the Muslim tradition one now attempts to reach, one simply cannot recover a scrap of information of real use in constructing the human history of Muhammad, beyond the bare fact that he once existed.