Kelsen advanced a sophisticated naturalist conception of intention and adumbrated a methodological strategy that would enable the transformation of the sophisticated naturalist conception of ‘intention’ into a cognizable object of legal science while simultaneously providing an explanation of the legal ‘ought’. The methodological strategy is the ‘inversion thesis’ which establishes that legal norms enable us to objectively identify and determine the ‘will’ or the intention of legal authority. Contrary to nineteenth century psychologism, Kelsen argues that it is not the case that the will or the intention of the sovereign determines what the norm is, rather it is the legal ought that ‘objectifies’ the will. However, it is argued that in spite of the fact that Kelsen advanced a sophisticated account of intentional action, he fails to understand the complexities of the notion of the ‘will’, intentional action and practical reason. What does he miss in his understanding of the notion of the practical? I will advance the view that the notion of the practical or deliberative involves, both in Kant and Aristotle, the transparency condition which establishes that the agent or deliberator intentionally acts for reasons that are self-evident or transparent to him or her. It is a recalcitrant feature of the deliberative standpoint that cannot be theorised. For Aristotle, Aquinas and Anscombe the deliberative standpoint can be known through the end or goal of the intentional action as this provides the form of the action. The end is presented as a good-making characteristic. As problematic as that might be, this means that the end needs to be presented as a good-making characteristic and therefore it involves evaluation. For Kelsen, the soundness of this conception is an insurmountable obstacle to theorise the ‘ought’ and therefore the ‘will’. Yet, surprisingly and contrary to Kelsen’s own notions, I will show that Kelsen’s ‘inversion thesis’ is parasitic on Aristotle–Anscombe’s ‘ought’.