The Holy Grail is a dish, plate or cup said to have been used by Jesus at the Last Supper and is an important symbol in the Arthurian myth. The Holy Grail represents the unattainable perfection that Arthur's knights must strive towards. In Book III, The Ill-Made Knight
, Arthur sends his knights out on a quest for The Holy Grail in the hope that the search may teach them morality and justice, and direct their violence and power towards a spiritual end. Ultimately, however, this fails: out of the three knights who eventually find the Grail, only one returns. The other two knights—Sir Percival and Sir Galahad—become too perfect for life itself and are unable to use their achieved perfection for justice in the realm. Thus, the Holy Grail represents not only spiritual perfection, but also the human perfection Arthur believes is fundamental to humanity. Arthur's quest for a just England is based on his assumption that man is ultimately good; but this assumption turns out to be false as a perfect man cannot exist (just as Sir Galahad and Percival die when they reach perfection) and hence is permanently unattainable for Arthur, just as the Holy Grail forever remains elusive.