Like T.S. Eliot's poem The Waste Land, much of The Natural is informed by a book entitled From Ritual to Romance, by Jessie Weston. Weston examines the many myths and legends that have grown up around the Holy Grail, particularly Arthurian legends, arguing that these Celtic and Christian stories have evolved from rituals relating to ancient fertility cults. These vegetative-fertility myths are so primeval, argues Weston, that they have insinuated themselves in myth and literature ever since the creation of writing.
These vegetative myths are based on nature, particularly on the cycle of the seasons. Spring is clearly a time of life and birth, when the trees grow leaves and animals come out of hibernation. Summer is the high tide of this life; in the fall things start to die, ending with the dark and dormant months of winter. Many ancient rituals marked the passage of the seasons, often occurring at times of solstice or equinox—even Christmas has strong roots in pagan winter solstice festivals. These rituals often invoked one god or another; when fall and winter came, these gods or goddesses were often thought of as "dying" only to be reborn, or replaced by new gods, the following spring.
In the Grail stories, Weston sees many characters as having parallels in the older vegetative-fertility myths. Most significant is the figure of the Fisher King, who, like the vegetative god, is inherently tied to the land. When the Fisher King is ill, the land itself is ill. This is the quest that Sir Perceval must fulfill: he must find a way to heal the Fisher King, and thus heal the land. In The Natural, Roy Hobbs is easily identified as being the Perceval figure, just as Pop Fisher is the Fisher King. But Roy is not simply Perceval; he is also the hero-god of the vegetative cycle itself, who defeats and replaces the previous god (the Whammer) only to be replaced himself many years later.
The Fisher King is a character found in several mythological sources, mostly Celtic in origin. However, he is best known from Arthurian mythology, particularly in the story of Perceval. There are several versions even of that story, but the basic elements are consistent. According to the story, Sir Perceval is out questing for the Holy Grail, as are all of Arthur's knights. While traveling, Perceval comes across a strange, ruined land. In the midst of this land he discovers a castle, and inside there is an old man. The old man has a regal bearing, but is deathly ill; in some versions of the story, his hands are wounded. The old lord invites Perceval to stay the night. The old man even gives the knight a special sword. After dinner, Perceval witnesses a strange procession. A youth enters the hall, carrying a white lance that holds a single drop of blood on its tip. Next, two more youth enter bearing golden candelabra. Finally, a beautiful maiden enters bearing a dazzling golden cup. Perceval wants to ask about these items, but he holds his tongue for fear of offending the old man. The next morning, Perceval awakes to discover that everyone is gone. He leaves the castle, which then disappears. Later, he encounters a woman who informs him that the lance was the one that pierced Jesus' side, and that the cup was no less than the Holy Grail itself. If Perceval had simply asked about these things, he could have brought about the healing of the old man, who is the Fisher King. If the King were healed, then the land would be healed as well. This story is found in Chrétien de Troyes's Conte del Graal, a series of stories about knights questing for the Holy Grail. Chrétien never finished the tale of Perceval, so the outcome of the knight's quest is not known, although most critics believe he was eventually successful.
In The Natural, the most obvious representative of the Fisher King is Pop Fisher. His hands are wounded, afflicted with "athlete's foot." As the team continues to lose, Pop is ill; the playing field is dry and dead, and the fans are absent. However, it is difficult to equate Pop Fisher entirely with the Fisher King. Malamud admitted to using Eliot's The Waste Land as an inspiration for his novel; one of the implications in Eliot's poem is that the waste land of modern civilization has no Fisher King to be healed.
In the legend of the Fisher King, the Waste Land the king's domain. Based on a belief that surfaces in a number of ancient cultures, the idea behind the Waste Land is that the King is so tied to the land that when he falls ill, the land itself falls ill as well. This parallel has a very literal meaning in the story of the Fisher King; when Perceval heals the King, the land, which is barren and cracked, suddenly bursts into new life, covered with plants and animals. In The Natural, the Waste Land is represented by the Knights' baseball field. When Roy first arrives, the field is dry and barren; there has been a drought, in both the team's long losing streak and the weeks without rain. Roy ends both of these droughts: when he makes his first hit, it not only results in a tie game (though not a win, at least not a loss), but it also heralds the arrival of a great storm that drenches the playing field for three days, making it green once again when the grass springs back to life.