Psychopaths have traditionally been excluded from the moral realm and have regularly been used as a paradigm case for explaining why emotions, or emotional knowledge, is necessary for the acquisition of moral knowledge. Psychopaths possess an affective deficit that results in an almost total lack of empathy. Emotionists argue that emotions (specifically empathy) are central to moral understanding, and that, since the psychopaths possess this affective deficit, they lack the capacity to acquire moral knowledge which is necessary to be morally responsible. Given recent neurological findings regarding psychopaths, I ague that Emotionists cannot use the psychopath as a case example supporting their argument that emotions are necessary for moral knowledge. I argue that despite psychopaths’ affective disorder, they possess three of the capacities (via cognitive mechanisms) considered by many to be necessary for moral responsibility. Those three capacities are the capacity to acquire moral knowledge, the capacity to be reason-responsive to moral demands, and the capacity to control one’s actions in light of moral demands and reasons. The upshot of my analysis is a rethinking of what it means to possess the right kind of emotional knowledge and a rethinking of the capabilities of psychopaths in relation to the moral realm. / Thesis / Doctor of Philosophy (PhD) / The commonly held view in philosophy is that psychopaths are not morally responsible. Psychopaths amount to about 1% of the current population and up to 25% of male criminal offenders. While these numbers seem rather small in comparison to the total population, philosophers, psychologists and behavioural psychologists regularly point to psychopaths for insight into the moral realm. The main aim of this dissertation is to block the Emotionist argument that emotions are necessary for moral knowledge and argue that psychopaths, despite their affective disorder, possess three of the capacities considered by many to be necessary for moral responsibility. The three capacities are the capacity to acquire moral knowledge, the capacity to be reason-responsive to moral demands, and the capacity to control one’s actions in light of moral demands and reasons. I conclude by arguing that psychopaths are capable of moral responsibility from a cognitive standpoint and that the Emotionist argument must seek another route to establish its conclusion that emotions are necessary for moral knowledge.