Since the latter half of the twentieth century, the number of people with Alzheimer's disease has grown to epidemic proportions. My project investigates the cognitive devastation of Alzheimer's disease from several perspectives. I first outline some medical models of Alzheimer's disease, incorporating Richard Dawkins' selfish gene theory. Next, I explore the linguistic experience of the patient. I study Arthur W. Frank's analysis of patient narratives and Elaine Scarry's theory of torture to explore the way in which Alzheimer's disease tortures the patient, stealing the patient's ability to speak and deconstructing the world of the patient. Finally, I think about the way in which Alzheimer's disease can support and challenge themes in Martin Heidegger's philosophy. In diagnosing Alzheimer's disease, the person experiences a conflation of fear and angst. I explore Heidegger's philosophy as it relates to the experience of the patient who shows no ability to function in-the-world, yet exists corporeally.