Do Masons take oaths on the Bible?
Yes, or on whichever Holy Book he holds sacred. In each of the three degrees, a Mason takes on an obligation that relates to the welfare of the organization, to his relationships with his fellow Masons, and to their mutual care and support.
These obligations are very old—truly medieval in character—and they include references to punishments from the Middle Ages. These punishments are understood to be strictly symbolic of the emotional distress an honest man would feel if he broke his sacred promises to his fellow men.