Light Yagami, the protagonist of Death Note, is a perfect example of the phrase “absolute power corrupts absolutely.” In the world of Death Note, people can obtain powerful notebooks owned by Shinigami—Japanese Gods of Death. If somebody writes a person’s name in the notebook with that person’s face in mind, they will die.
Light receives a notebook from Ryuk, a Shinigami who comes to the human world out of boredom. Light’s subsequent ascension to a position of unlimited power allows him to impose his personal justice on the world around him, but the delusion this power unlocks ensures that his justice is paradoxically unjust. As he proceeds with his Reign of Terror under the pseudonym Kira, he develops brutish tendencies, becoming more hardened with every murder.
The best way to understand Light’s descent into madness is by interrogating the psychic apparatus of his psyche, conceptualized by the Austrian psychoanalyst Sigmund Freud as the Id, the Ego, and the Superego. Although Freud’s theories have been mostly discarded in psychiatry, they are still employed in literary studies, and can be useful in examining depicted motivations of fictional characters.
Id, Ego, Superego
The id is the part of the psyche that operates according to the pleasure principle. It is the part that acts impulsively, and often selfishly, pursuing the easiest and most immediate gratification available. The most primitive part of the psyche, the Id wants what it wants now.
Mediating the id’s desires is the ego, which either rejects them through the process of repression, or converts them into something more realistic. It is the reasoning, decision-making apparatus which deals with the external world.
Finally, the superego subconsciously retains social and cultural rules and norms. The information it carries is largely obtained from a person’s parents, teachers, and other early authority figures, and it functions to control the impulsive id and channel the ego’s rational decision-making towards moral ends.
Light Yagami’s case is an interesting one because it is one that isn’t often told. By obtaining the Death Note, he essentially becomes a Shinigami—a Japanese God of Death. Having the power to control death causes a person to ascend to a near-divine role, as they become the judge, jury, and executioner presiding over the most basic of all decisions—whether someone lives or dies. When Light recognizes that he can instigate the murders of countless people without getting caught, he becomes absorbed by the fact that he can kill—and becomes more and more uninterested in the question of whether or not he should.
What’s happened is that Light’s id—usually repressed in the unconscious part of the psyche and mediated through the rationality of the ego—has started to collude with the subconscious superego. The sense of justice imbued in Light by his father, the Chief of Police, as well as by his family, his school, and other institutions which have influenced him throughout his life, is essentially his undoing. His divine power unlocks the id, because the superego contorts to suit a hyper-accentuated version of Light’s sense of justice, which happens to resonate with the distorted desires of the id. Essentially, Light’s idea of a perfect world in which justice prevails becomes the goal of a powerful Id given free reign to act impulsively and without consequence. The fact that his superego is in agreement with the Id negates the role of the ego, which cannot intervene with something that the superego has deemed appropriate.
Essentially, Light is willing to pursue his idea of a utopia at all costs, which is why his divine, godlike power transforms him into a monster. In the mirror, Light sees a God; however, the image is distorted. Gods and monsters are the same thing where Gods of Death are concerned. The most interesting part of Death Note in relation to this theory is that Light has his Shinigami, Ryuk, get rid of the eponymous Death Note at one point. This is done in an attempt to convince L, the world class detective who is catching up to Light, that he is not Kira, the celebrity killer who is said to be killing dozens of people every week.
When Light forfeits the Death Note, he loses all memory of it. This is because of one of the rules of the Note—when ownership of the Note is forfeited, the previous owner will not remember anything related to it. Light’s Id sinks back into the unconscious, and his ego becomes capable of performing its function again. However, his return to a more civilized and sane state of mind happens as the result of a decrease in his power.
Paradoxically, Light’s ability to remain sane is inversely proportional to the amount of power he can wield. When his power is boundless, he descends into the lowest, most primal chambers of his psyche. In spite of this descent, he becomes remarkably more intellectually capable. When he loses this power, he becomes reasonable, empathetic, and to put it plainly, humane. Light’s id is immediately unleashed once more when he regains ownership of the Note, highlighting that the effect of this power on his psyche was not a singular occurrence, but something that would happen a hundred times over given the same conditions.
The depiction of Light Yagami is Death Note highlights the fact that power is a double-edged sword. His divine power desensitizes him to its consequences—Light no longer thinks like a person, he thinks from the perspective of a God of Death, in which people are nothing more than pawns. Driven by the conviction that what he is doing is right, Light becomes more committed to his cause in direct proportion to the amount of power his superego affords the id.
Slavoj Zizek once wrote that “desire’s raison d’être is not to realize its goal, to find full satisfaction, but to reproduce itself as desire.” Thus, Light’s distorted desires are a dragon he can never stop chasing. Disguised as a desire for a better world, Light’s brutal predisposition to murder is something that becomes necessary to satiate his psyche’s thirst for exhibiting power. The world will never be perfect in his eyes—not because it isn’t, but because he is a God of Death, and a God of Death must take lives, even if it makes him a monster.