Moral judgments seem to claim objective validity. To believe torture is permissible is a mistake. But how should we understand this error? Within Kantian ethics, this objectivity is currently seen as the result of a process of "construction": moral principles are rules of action to which we subscribe as rational beings. Moral knowledge, then, takes shape through a rational process. This research argues that Kant employed a more robust idea of moral knowledge through a close analogy between the practical and theoretical. Not only does this provide a more faithful Kant interpretation, but also a stronger foundation for moral knowledge.