 According to the ‘frontloading’ argument, we can have conclusive apriori knowledge of material conditionals of the form (PQTI  \(\supset\) S). Chalmers argues that all empirical information relevant to justifying a verdict about S can be ‘frontloaded’ into the antecedent of the conditional, so information about one’s real-world environment, E, cannot play any essential role in justifying verdicts about the conditional. If E is itself apriori entailed by PQTI, it is not needed to justify a verdict about the conditional. And if E is not apriori entailed by PQTI, E will be irrelevant to justifying a verdict about the conditional. So our justification for the application conditionals that ground 1-intensions is wholly apriori, and immune to empirical  defeat.[20]