 No matter how intuitive, Hempel proceeded to demonstrate that this creates a paradox. By Nicod’s criterion, “\((x)(Rx \supset Bx)\)” is confirmed by ravens that are black. But, by that same standard, “\((x)(\neg Bx \supset \neg Rx)\)” is confirmed by non-black non-ravens, such as white shoes! Since these are logically equivalent and have the same empirical content, they must be confirmed or disconfirmed by all and only the same instances. This means that—no matter how counter-intuitive—the lawlike hypothesis, “All ravens are black”, is confirmed by observations of white shoes! Since these hypotheses are also equivalent to “\((x)(\neg Rx \vee Bx)\)”, which asserts that everything either is not a raven or is black, it is also the case that observations of non-ravens confirms the hypothesis, regardless of their color. Observations of non-ravens, however, unlike those of black ravens, confirm alternative hypotheses, like “All ravens are blue” and “All ravens are green”. Hempel’s point was that the application of Nicod’s criterion means that, since even observations of non-ravens are confirmatory, the class of neutral instances in fact has no members.