 While some instances of self-deception seem morally innocuous and others may even be thought salutary in various ways (Rorty 1994), the majority of theorists have thought there to be something morally objectionable about self-deception or its consequences in many cases. Self-deception has been considered objectionable because it facilitates harm to others (Linehan 1982) and to oneself, undermines autonomy (Darwall 1988; Baron 1988), corrupts conscience (Butler 1722), violates authenticity (Sartre 1943), manifests a vicious lack of courage and self-control that undermine the capacity for compassionate action (Jenni 2003), violates an epistemic duty to properly ground self-ascriptions (Fernández 2013), or violates a general duty to form beliefs that “conform to the available evidence” (Nelkin 2012). Linehan (1982) argues that we have an obligation to scrutinize the beliefs that guide our actions that is proportionate to the harm to others such actions might involve. When self-deceivers induce ignorance of moral obligations, of the particular circumstances, of likely consequences of actions, or of their own engagements, by means of their self-deceptive beliefs, they may be culpable. They are guilty of negligence with respect to their obligation to know the nature, circumstances, likely consequences and so forth of their actions (Jenni 2003; see also Nelkin 2012). Self-deception, accordingly, undermines or erodes agency by reducing our capacity for self-scrutiny and change. (Baron 1988) If I am self-deceived about actions or practices that harm others or myself, my ability to take responsibility and change are also severely restricted. Joseph Butler, in his well-known sermon “On Self-Deceit”, emphasizes the ways in which self-deception about one’s moral character and conduct, ‘self-ignorance’ driven by inordinate ‘self-love’, not only facilitates vicious actions but hinders the agent’s ability to change by obscuring them from view. Such ignorance, claims Butler, “undermines the whole principle of good … and corrupts conscience, which is the guide of life” (“On Self-Deceit”). Existentialist philosophers such as Kierkegaard and Sartre, in very different ways, viewed self-deception as a threat to ‘authenticity’ insofar as self-deceivers fail to take responsibility for themselves and their engagements past, present and future. By alienating us from our own principles, self-deception may also threaten moral integrity (Jenni 2003). Furthermore, self-deception also manifests certain weakness of character that dispose us to react to fear, anxiety, or the desire for pleasure in ways that bias our belief acquisition and retention in ways that serve these emotions and desires rather than accuracy. Such epistemic cowardice and lack of self-control may inhibit the ability of self-deceivers to stand by or apply moral principles they hold by biasing their beliefs regarding particular circumstances, consequences or engagements, or by obscuring the principles themselves. In all these ways and a myriad of others, philosophers have found some self-deception objectionable in itself or for the consequences it has on our ability to shape our lives.