I present in this dissertation a theory of moral disillusion. In chapter 1 I explain moral innocence and its loss. I show that becoming morally responsible requires shattering the illusion that one is not an appropriate candidate for the reactive attitudes. The morally responsible individual must understand that she can be an agent of wrongdoing. In chapter 2 I explore the nature of the understanding that accompanies the different phases of disillusion. I show that moral disillusion is an ability, not to follow moral principles, but to question them. In chapter 3 I argue that another phase of disillusion involves an acquaintance with evil. One shatters the illusion that only malicious individuals can be evildoers. Morally good people can also bring about evil. I conclude that evil is the exploitation of the extremely vulnerable. In chapters 4 and 5, I analyze more complex phases of moral disillusion. These stages are characterized by an understanding that one can be an agent of unchosen evil, that one might bring about evil even when pursuing the morally best course of action, and that one can be morally responsible for doing so. In order to understand unchosen evil and the tragedy of inescapable moral wrongdoing, the individual sees that moral responsibility ought to track what we care about, rather than what we believe. In chapter 6 I show that Kierkegaard's conception of the self is a philosophy of moral disillusion. I argue that his prescription that we shatter moral illusions is congruent with Harry Frankfurt's prescription that we ought to care about some things and not others. From this discussion emerges the explicit distinction between moral disillusion and moral goodness. Moreover, I conclude that the morally disillusioned are morally accountable for more than those still harboring moral illusions. Although moral disillusion does not entail becoming morally good, by acquiring the ability to raise questions about moral principles and to affect the content of one's cares, one acquires the ability to take responsibility for, and potentially minimize, evil. To have and understand these abilities, but not to care about them, increases one's moral accountability.