Crusoe’s discovery of a mysterious single footprint in the sand is one of the most unforgettable and significant events of the novel, since it condenses into one moment Crusoe’s contradictory attitude toward other humans: he has been craving human society, yet when it arrives he is deeply afraid of it. Crusoe himself comments on this irony when he says, “How strange a checker-worker of Providence is the life of man! . . . Today we love what tomorrow we hate!” Indeed, he hates this human intruder almost as much as he hates the devil himself, whose footprint he originally suspects it is. It is hard to explain why Crusoe immediately leaps to a negative conclusion about the footprint, why he is sure it is the sign of an enemy rather than a friend. Crusoe’s reaction shows how solitude has become his natural state, making any human contact seem unnatural and highly disturbing.
The appearance of Friday is a major development in the novel, which has had only one character in it for a large part. The sweetness and docility of Friday, who is a cannibal, and the extraordinary ease with which Crusoe overcomes Friday’s two pursuers, leads us to rethink Crusoe’s earlier fear. Crusoe lives in terror of the cannibals for many years, scarcely daring to leave his cave and reduced to a cavemanlike existence. Then, in only a few minutes, he stops two cannibals and makes another his lifelong servant. Suddenly it seems that Crusoe has feared not the savages themselves, but his own exaggerated mental image of them. Thus, Crusoe’s self-awareness arises as a major theme of the novel, and Crusoe illustrates that a better understanding of himself and his fears leads him to more prosperity and satisfaction in life. Friday’s instantaneous servitude to Crusoe also raises questions about Crusoe’s sense of his own rank and power. Crusoe easily could lift Friday from the ground when Friday grovels before him, but he does not. Without so much as a second thought, Crusoe accepts Friday as a servant and an inferior, assuming his own superiority. Friday may be the first New World “savage” in English literature to force a questioning of whether white people should automatically assume superiority over other races.
Crusoe’s religious awareness continues to grow in these chapters. Almost every major event is taken either as cause for repentance or as proof of God’s mercy. Crusoe’s first assumption on seeing the footprint on the beach is that it is a mark of the devil, showing that supernatural or divine explanations have priority over natural ones in his mind. When the gunshots are heard from the wrecked ship, Crusoe is reading the Bible, and when he compares the fate of the shipwrecked men to his own fate, it seems as if he begins to see the whole process as a religious lesson. When Crusoe decides not to open fire on the cannibal feast, he does so out of a religious conviction that he has not the “authority or call . . . to pretend to be judge and executioner upon these men as criminals.” Though he later admits there were also practical reasons for not killing them, his religious reason comes across with sincerity. Perhaps most strikingly, in Chapter XXII Crusoe compares his disobedience of his father to Adam and Eve’s disobedience of God in Eden, referring to his own “original sin.” The Bible, the devil, and God are all becoming very closely entwined in the fabric of Crusoe’s everyday life on the island.