場所：京都大学 文学部校舎１階 会議室
Masashi Kasaki (Nagoya University, Osaka University)
Damian Szmuc (University of Buenos Aires, CONICET)
16:00–17:30: Damian Szmuc “Paraconsistent logics, Meta-paraconsistent logics and beyond”
17:45–19:15: Masashi Kasaki “How Many Cartesian Skepticisms?“
Each of the three ways of demarcating the two kings of skeptical hypotheses entails that certain solutions to the skepticism with the brain in a vat hypothesis or the evil genius hypothesis won’t
work for the skepticism with the dreaming hypothesis. If the first way is correct, the denial of closure cannot be marshalled against the skepticism with the dreaming hypothesis. If the second way is correct, the safety-based response to the skepticism with the brain in a vat hypothesis or the evil genius hypothesis does not fare well with the skepticism with the dreaming hypothesis. And yet, if the third way is correct, it is difficult to dispel the dreaming hypothesis as metaphysically impossible.
In this paper, I will argue that the three ways of differentiating between the two kinds of skeptical hypotheses are not well-grounded. Notice that even the brain in a vat hypothesis is compatible with, or even strongly, cannot contradict certain ordinary empirical propositions, such as there are computers, there are scientists, there are brains, and so on. On the other hand, the dreaming hypothesis includes some true ordinary empirical propositions. Once the brain in a vat hypothesis is set up so as to include little true ordinary propositions, there is no reason to differentiate between the brain in a vat hypothesis and the dreaming hypothesis, and hence the first way fails. The same can be said of the relationship between the evil genius hypothesis and the dreaming
hypothesis. Indeed, if the dreaming hypothesis includes less true ordinary propositions, then the possible worlds in which it is true are more distant from the actual world. Thus, the second way also fails. The same consideration is advanced against the third way. If my arguments are correct, one needs no distinct response to the skepticism with the dreaming hypothesis. Good news!