In the original Beowulf epic, Grendel displays nothing but the most primitive human qualities. In Grendel, however, he is an intelligent and temperamental monster, capable of rational thought as well as irrational outbursts of emotion. Throughout the novel, the monster Grendel often seems as human as the people he observes. Grendel’s history supports this ambiguous characterization. As a descendant of the biblical Cain, he shares a basic lineage with human beings. However, rather than draw Grendel and humankind closer together, this shared history sets them in perpetual enmity. In this regard, Grendel recalls the nineteenth-century literary convention—used in novels such as Victor Hugo’s The Hunchback of Notre-Dame and Mary Shelley’s Frankenstein—of using monsters to help us examine what it means, by contrast, to be human. Indeed, aside from Grendel’s horrible appearance and nasty eating habits, very little actually separates him from humans. Even his extreme brutality is not unique—time and again, Gardner stresses man’s inherent violence. Moreover, Grendel’s philosophical quest is a very human one, its urgency heightened by his status as an outsider.
The novel follows Grendel through three stages of his life. The first stage is his childhood, which he spends innocently exploring his confined world, untroubled by the outside universe or philosophical questions. Grendel’s discovery of the lake of firesnakes and the realm beyond it is his first introduction to the larger world, one full of danger and possibility. As such, crossing the lake is a crucial step for Grendel in his move toward adulthood. The second step—which decisively makes Grendel an adult—occurs when the bull attacks him, prompting him to realize that the world is essentially chaotic, following no pattern and governed by no discernible reason. This realization, in turn, prompts the question that shapes Grendel’s adult quest, perhaps the greatest philosophical question of the twentieth century: given a world with no inherent meaning, how should one live his or her life? In the second, adult stage of his life, Grendel tries to answer this question by observing the human community, which fascinates him because of its ability to make patterns and then impose those patterns on the world, creating a sense that the world follows a coherent, ordered system. The third and final stage of Grendel’s life encompasses his fatal battle with Beowulf and the weeks leading up to that battle. The encounter provides, ultimately, a violent resolution to Grendel’s quest.