The devil’s circle is an extension of samsara, the Buddhist cycle of birth, death, and rebirth. Both samsara and the devil’s circle are ultimately marred by extreme pain and suffering. Despite this fact, many people create a devil’s circle for themselves. This is made in an attempt to associate themselves with something stable, albeit painful, and an attempt to deny impermanence. The devil’s circle does provide temporary relief from instability, but as instability and interconnectedness are the core tenets of reality, that relief is also unstable. In a final attempt to create stability, some people continue to completely reject change and further their obsessive-compulsive behaviors. This attempt only tightens the grip of the devil’s circle and causes harm to the user and those around that person. In Christopher Nolan’s film, Memento, the character of Leonard Shelby has trapped himself in a devil’s circle of his own design, one in which any attempt to escape sends him spiraling deeper into the circle, and extending the grasp that Mara holds over him.The all-encompassing backdrop of the film and its narrative is that of memory; through that foundation, all other themes are explored. In order to fully grasp the nature of memory and its relationship between Leonard and his devil’s circle, the works of another philosopher must first be superimposed. In his Treatise of Human Nature, David Hume attempted to rectify the dichotomy in the Mind-Body problem. Hume proposed that human consciousness is split into two distinct spheres: impressions and ideas. Impressions are at the moment, lively, and vivid, while ideas are memories of impressions, the imagination, and less coherent. In Memento, Leonard attempts to tie himself down to impressions by means of his photographs, notes, and tattoos; these are all attempts to keep Leonard in the impression sphere rather than the idea-sphere, which is severely damaged. Even with the idea-sphere of his brain-damaged, Leonard is still susceptible to the power of habit. After all, even without short-term memory, he is able to build habits and automatic repetitions, repetitions that send him deeper into his devil’s circle. The problem here, Hume argues, is that humans can only reason from their past conclusions, and generally disregard the underlying reasoning or logic of those conclusions. This is one of the core problems for Leonard, as although he attempts to fix himself in the impression sphere, his personal identity continues to fluctuate.One of the core tenants of both Hume’s philosophy and that of Buddhism is a lack of fundamental essence or a soul. Hume, for example, describes the soul as a commonwealth, composed of interrelated and every changing elements. For Buddhism, this is radical contingency. This lack of essence and personal identity is another core theme in Memento, and the film ultimately makes the viewer question the moral responsibility of Leonard. After all, as Leonard is the personification of lacking a core identity, logic should dictate that he cannot be held morally responsible for any of his actions. Hume, however, has an answer to this seeming contradiction, one that is tied back to the personal commonwealth. The minds of men, beyond dividing spheres of impressions and ideas, also act as mirrors to one another. It is the reactions of others and their perceptions, then, that create an identity. Buddhism would tend to agree with Hume, as it teaches of Pratityasamutpada or the dependent origin of all things. This origin is the beginning of samsara and the devil’s circle, and to break free of that cycle is to reach nirvana and true peace. For Leonard to reach this peace and break free of the devil’s circle, he must first realize that he is trapped within it.The final underlying theme of Memento and the final spiral of Leonard’s devil’s circle is that of truth and the nature of reality. In the film, Teddy mentions the unreliability of eyewitness testimony to Leonard in an attempt to illustrate that Leonard’s perception of reality is not true. Hume makes the point of connecting the perception of reality to that of time. The perception of both stems from the awareness of the two spheres of the mind, impressions, and ideas, in never-ending succession. This is the underlying logic that all ideas are linked to all other ideas, and the basis for the conclusion that humans can only reason from their past conclusions, to the point of fault. Leonard is eventually confronted with the truth and even writes a reminder to himself to get a tattoo informing him that his task has been completed. But, in the ultimate rejection of radical contingency, he rips up that note and goes after Teddy. The devil’s circle he crafted for himself is too strong and, rather than breaking free, he only falls deeper into the grasp of Mara.Reality is not unlike being adrift in a great ocean. The water is ever-changing, and the unknown is all-encompassing. Humans, who are creatures inherently adverse to the unknown, fear the ever-changing nature of reality and have developed a wide variety of coping mechanisms to reject that nature, the devil’s circle not least among them. Both David Hume’s philosophy and Buddhism teach of the unstable nature of human assumptions and their coping mechanisms, and the dangers of adopting the devil’s circle as a way of life. Memento acts as the fundamental case study of the devil’s circle, exploring the interconnected themes of memory, moral responsibility, identity, and perception of truth. Leonard rejects the lessons all of those themes attempt to instill: the interconnectedness of reality, the lack of a fundamental essence, and the impermanence of reality. In effect, then, Leonard is rejecting the fundamental truths of radical contingency, and entering into the same unsustainable cycle of violence that was present in No Country For Old Men. Even in Leonard’s death, there is unlikely to be an escape or peace. He will still be tied to samsara, the devil’s circle, and will repeat his actions ad infinitum.