"Perhaps the most famous icon of the holiday is the jack-o-lantern. Various authorities attribute it to either Scottish or Irish origin. However, it seems clear that it was used as a lantern by people who traveled the road this night, the scary face to frighten away spirits or faeries who might otherwise lead one astray. Set on porches and in windows, they cast the same spell of protection over the household. (The American pumpkin seems to have forever superseded the European gourd as the jack-o-lantern of choice.) Bobbing for apples may well represent the remnants of a Pagan 'baptism' rite called a 'seining', according to some writers. The water-filled tub is a latter-day Cauldron of Regeneration, into which the novice's head is immersed. The fact that the participant in this folk game was usually blindfolded with hands tied behind the back also puts one in mind of a traditional Craft initiation ceremony."
-- Mike Nichols, “All Hallow's Eve’’