Papers published about the need for a theoretical core in the information systems (IS) discipline can be characterized as either nature-of-the-discipline commentaries or logicof-the-core commentaries. The former articulate the authors’ views on those phenomena that research in the IS discipline ought to investigate. The latter scrutinize some of the logic that underlies arguments made by those who either support or reject the need for a theoretical core. Unfortunately, nature-of-the-discipline commentaries are unlikely to help clarify or resolve fundamental issues that underpin the debate. Too often they are based on idiosyncratic views that are difficult to either justify or refute. Logic-ofthe-core commentaries, however, lay bare the arguments made by the protagonists so they can be evaluated. In this paper, I examine the logic-of-the-core arguments made by Lyytinen and King (2004) and evaluate their validity.