Abstract

According to dogmatism, our perceptual experience provides immediate justification for our beliefs about the external world. In particular, according to some versions of dogmatism, an experience with phenomenological strength (aka ‘phenomenal force’) is sufficient for immediate perceptual justification (call this ‘the phenomenal sufficiency thesis’). However, the sufficiency thesis has been challenged based on cases in which certain imaginative experiences with phenomenal force fail to justify. So, the dogmatist may claim that while phenomenal force is not sufficient, it’s still necessary for immediate perceptual justification (call this ‘the phenomenal necessity thesis’). In this paper, I would like to challenge the phenomenal necessity thesis on the basis of a psychopathological condition called ‘derealization disorder’. In particular, I’ll argue that cases of derealization show that phenomenal force isn’t necessary for immediate perceptual justification.