Hempel describes the paradox in terms of a hypothesis that all ravens are black. This statement is equivalent, in logical terms, to the statement that all non-black things are non-ravens. If one were to observe many ravens and find that they were all black, one's belief in the statement that all ravens are black would increase. But if one were to observe many red apples, and concur that all non-black things are non-ravens, one would still become more sure that all ravens are black.