ABSTRACT
This chapter compares the two kinds of possibility such as epistemic and natural possibility. There is a positive logical connection between natural and relative possibility, since knowledge that an event of a particular kind is naturally possible can play the same logical part as knowledge of its past occurrence. The chapter distinguishes between three kinds of probability-statement, and it may throw some light on possibility and its relation to probability and also considers how far the same classification can be applied to possibility. The kinds of probability-statement are corresponding to Carnap's 'probability1', where the evidence is actually specified as a part of the statement and is statistical, corresponding to 'probability2', the evidence being specified as a part of the statement, and being purely specificatory, and where no evidence is specified, the whole statement being relative to the available evidence.
