In legal decisions standpoints can be supported by formal and also by substantive interpretative arguments. Formal arguments consist of reasons the weight or force of which is essentially dependent on the authoritativeness that the reasons may also have: In this connection one may think of linguistic and systemic arguments. On the other hand, substantive arguments are not backed up by authority, but consist of a direct invocation of moral, political, economic, or other social considerations. Formal arguments can be analyzed as (...) exclusionary reasons: The authoritative character excludes—in principle—substantial counterarguments. Formal arguments are sometimes used to conceal value judgements based on substantial arguments. This paper deals with reconstructing problems regarding this strategic use of formal arguments in legal decisions, with a focus on linguistic argumentation. (shrink)