Unlike the question of whether self-deception can be understood on the model of other-deception, the relationship between the two phenomena at the level of practice is hardly ever explored. Other-deception can support self-deception and vice versa. Self-deception often affects not only the beliefs and behavior of the self-deceiving person but also the beliefs and behavior of others who may become accomplices of self-deception. As I will show, however, it is difficult to describe this supportive relationship between self-deception and the deception (...) of others without conceptual contradiction. While “deflationary” approaches offer a convincing way to avoid the so-called paradoxes of self-deception, they do not resolve the conceptual tensions that arise here. I conclude by outlining a solution. (shrink)

I critically examine the plausibility of Kant’s conception of rationalising, a form of self-deception that plays a crucial role for Kant’s moral psychology and his conception of the functions of critical practical philosophy. The main problem I see with Kant’s conception is that there are no theory-independent criteria to determine whether an exercise of rational capacities constitutes rationalising. Kant believes that rationalising is wide-spread and he charges the popular philosophers and other ethical theorists with rationalising. Yet, his opponents could, in (...) turn, charge him with rationalising and some theorists, namely Act-Consequentialists, seem to be in an even stronger position to charge Kant with rationalising than vice versa. In response, I propose standards that do not assume a specific normative theory and that become apparent when we look at clear-cut abuses of rationality. These standards of minimally decent reasoning can help us diagnose rationalising. I develop these standards by looking at inadequate uses of rational capacities that should strike us as problematic regardless of the specific ethical theory we adopt. I emphasise that even an abuse of rational capacities can yield true results and that we can never tell from a single judgement that someone rationalises. Rather, we must look for patterns. (shrink)