In this paper I will argue that Boghossian’s explanation of how we can acquire a priori knowledge of logical principles through implicit definitions commits a transmission of warrant-failure. To this end, I will briefly outline Boghossian’s account, followed by an explanation of what a transmission of warrant-failure consists in. I will also show that this charge is independent of the worry of rule- circularity which has been raised concerning the justification of logical principles and of which Boghossian is fully aware. My argument comes in two steps: firstly, I will argue for the insufficiency of Boghossian’s template which is meant to explain how a subject can acquire a warrant for logical principles. I will show however that this insufficiency...