In this issue of JCE, Douglas Diekema argues that the best interest standard (BIS) has been misemployed to serve two materially different functions. On the one hand, clinicians and parents use the BIS to recommend and to make treatment decisions on behalf of children. On the other hand, clinicians and state authorities use the BIS to determine when the government should interfere with parental decision-making authority. Diekema concedes that the BIS is appropriately used to "guide" parents in making medical treatment decisions for their children. But he argues that the BIS is inappropriately used as a "limiting" standard to determine when to override those decisions. Specifically, Diekema contends that the BIS "does not represent the best means for determining when one must turn to the state to limit parental action." He argues that this limiting function should be served by the harm principle instead of by the BIS. I contend that we should not reassign the BIS's limiting function to the harm principle. In this article I make two arguments to support my position. First, the BIS has effectively served, and can serve, both guiding and limiting functions. Second, the harm principle would be an inadequate substitute. It cannot serve the limiting function as well as the more robust BIS.