It has been argued by several authors that material implication does not fully capture the meaning of "If formula_52 then (see the paradoxes of material implication). "For every object, formula_94 is either black or not a raven" is "true" when there are no ravens. It is because of this that "All ravens are black" is regarded as true when there are no ravens. Furthermore, the arguments that Good and Maher used to criticize Nicod's criterion (see , above) relied on this fact – that "All ravens are black" is highly probable when it is highly probable that there are no ravens.