I briefly summarise some talks below. (See here for the full programme with abstracts.)
In some cases, there is no non-circular justification of a particular rational norm or rule. For instance, Hume's famous discussion of inductive inferences seems to show that there is no non-circular justification of inductive inferences. One might try to justify inductive inferences on the basis of their past success but, as Hume pointed out, this justification itself is inductive and hence circular. In his talk "Circularity and Objective Rational Norms", Jonathan Ichikawa (British Columbia) argued that that some norms or rules are simply and brutely objectively correct, even if there is no non-circular justification of them and, and even if we cannot distinguish the good cases of circular justification from the bad cases. He discussed some interesting implications to the externalism/internalism debate about rationality.
Neil Van Leeuwen's (Georgia State)"Imagination and Sacred Value" was about the peculiar features of religious preferences and beliefs. First he introduced Scott Atran's recent study which reveals the the peculiar features of religious preferences, such as the violation of transitivity and the lack of temporal discounting. Then, he argued that, in causing behaviour, the non-standard system of preferences in religious contexts (called "sacred value") should be combined with the non-standard system of beliefs. In particular, he argued the “beliefs” that interact with sacred values should be more similar to imaginings than to ordinary factual beliefs, which is consistent with his claim in this paper.
In his talk "Cognitive Bias and the Evolution of Self Deception", James Marshall (Sheffield) discussed irrational biases from an evolutionary point of view. He critically discussed the evolutionary account of overconfidence by Johnson & Fowler and proposed his alternative account according to which overconfidence is a sort of behavioural bias (i.e., the bias of behaving as if the probability of an event is other that it actually is). Then, he connected the proposal with the account of self-deception by Robert Trivers which predicts the selection pressure for individuals that act as if the state the world were different that what it actually is. Marshall presented the formal, mathematical model of Trivers' account.
I gave a talk "Aliefs and Pushmi-Pullyu Representations" in which I argued that pushmi-pullyu representations (PPRs), introduced by Ruth Millikan, play the crucial role in some kinds of irrational human behaviours. According to Millikan, there are three kinds of representations; descriptive representations, directive representations and PPRs. The job of descriptive representations is to describe states of affairs. The job of directive representations is to direct behaviours. And, the job of PPRs is to describe states of affairs and direct behaviours at the same time. In this talk, I discuss Tamar Gendler's skywalk case, and provide the PPR account of it. On the one hand, the PPR account is similar to Gendler's alief account because PPRs share many features with aliefs. But, on the other hand, the PPR account is more plausible than the alief account because the former is free from the major objections to the latter, including what I call "the hodgepodge objection" and "the disunity objection".