The Holy Grail is a symbolic talisman around which numerous medieval legends and poems revolve. It may have started out as a Celtic pagan tale and then later became associated with the cup used at the LAST SUPPER in which the blood of Christ was collected. The Grail was sought by various knights of King Arthur's Round Table in several medieval romances. The quest for the Grail proved futile for all but one since the Grail can only be found by a hero free from sin. Most everyone who left out in search of the Grail failed to achieve their quest. Legend has it that Galahad, a knight of unexcelled spiritual purity, succeeded in the quest for the Holy GRAIL. Galahad was taken into heaven with the Holy Grail.
In summary, the Holy Grail is unachievable for any group or collective because no group (or collective) and few individuals can be free of sin. Yet, this does not stop politicians and others, from promising to seek the equivalent of the Holy Grail of socialism to raise society towards a nirvana in which everyone is taken care of with equality and fairness to all.