 However, before we rest too easily with this conclusion, we must first address an important objection to default  principles.[4]  The challenge insists that they are all vacuously true simply in virtue of their logical form. Since default principles are universally quantified conditionals, they can be false only if they have an instantiation in which the antecedent is true and the consequent is false. The worry behind the vacuity objection is that the logical form of a default principle in conjunction with some very plausible assumptions about moral explanation entails that whenever the consequent of a default principle is false, its antecedent will be false as well, in which case the principle itself is vacuously true. Consider the following inane default principle: